There seems to be alot of chroma abrasion with the default canon lense, thats not cool... any ideas? this is not my footage, And I cannot seem to find any noticable chroma abrasion in Dempsey's work.

here is an example of what i'm talking about.

http://img70.imageshack.us/img70/2486/bluelinesov3.jpg

Many blame the lens for this effect; My XL H1 creates same kind of HDV image on borders between light and dark objects. However, such an effect almost disappears and is hardly visible with the image from HD-SDI signal (captured with AJA Xena card and compressed with Cineform Prospect HD). So, my prelimanary conclusion has been that the question is not only of the lens but as well about the HDV compression. But, to be sure of this, I'm going to test this by capturing both the HDV and HD-SDI signal simultaneously. That should give a good idea how much this effect you observed depends on the lens.

May I suggest you perform a test using the photo modes of the XL-H1.

First, setup a shot using a tripod.

1. Take a snapshot using the Photo button. In my experience you will get a ".jpg" over 1 megabyte.

2. While recording the same material, start recording and also take a snapshot.
(I do not currently know what the size of this ".jpg" will be.)

3. While playing back the tape, take another snapshot. This should be another ".jpg", but it will only be about half a megabyte.

Compare the three snapshots. I belive the first will be the best quality. I have not performed test 2. Test 3 will be inferior, in my opinion.

However, all three will have used the same lens.

I spoke with Joe Bogacz (Assistant Director of Product Development and Support for Canon's Video Division) at great length before I purchased the camera. He states that the chroma abberation is not the lens and that they have had the lens tested for this effect.

It will be interesting if the CA only appears after the image has gone through the HDV compression. I am only assuming that the snapshots taken using "1" are processed differently, processed without going through the HDV compression.

I really want to purchase this canon... but if chroma aberration is an issue I might have to reconsider waiting untill there is somthing nicer..... Any idea if it does this at 1280x720? or just 1920x1080?

or maybe only certain recording methods?

We need dempsey to speak up lol, his videos don't have any noticable abberation, not that i've seen anyway.

any test results?

I don't think that's chromatic abberation. The CA that I have measured (and I certainly don't claim to have done a complete set) on the 20X lens shows it to be about a pixel at most at the edges of the picture. So if it isn't CA what is it? For starters keep in mind that the chroma information is sampled at 1/4 the rate of the luminance information (in HDV mode; in the SDI signal it's 1/2). You can think of this as meaning that the picture is painted in black and white first with a fine brush with the color later applied with one 4 times wider. Colors will overlap the boundaries of their objects for this reason. The reason this is done is that the human eye does not resolve color to the same degree that it does brightness and the fact that less color information can be transmitted/stored is what makes color video possible. Ordinarily this 'blur' of color is not noticed but if you go looking for it you will find it. It is a genuine problem when trying to use color for keying. That's when you really want 4,2,2 or beter still, 4,4,4 sampling.

Second, the camera at its default settings does quite a bit of sharpening. What this means is that near the boundary between the blue sky and the black jacket the blue sky is rendered brighter on the sky side and the jacket darker on the jacket side. This is, I believe, the cause of what you are seeing. To confirm, reduce sharpening and see if you like the image better. I also think that in this case the situation is exacerbated by less than perfect focus. Try for better focus next time.

Finally, artifacts of this sort are inherent in the way video which has been separated into luma and chroma is processed. As I am not privy to any of the details of Canon's processing I can't say which leads to what but I do encourage people to look at images of the SMPTE chart generated by the camera (http://www.pbase.com/agamid/image/53638038). Note that this image shows areas of appreciable width between the bars which are not the correct color (not the color of either of the adjacent bars) but are certainly not caused by the lens as no lens was involved.

Another way to convince yourself that it isn't CA is to mount one of your favorite primes to the camera and capture some images. You'll see the same sort of artifacting in those images.

[Edit: a couple of typos]

Dear A. J.

Great post!

Thank you!

No amount of rationalizing can change the fact the the H1 has problems with CA. You can see examples of it in practically every clip on this board. CA was also visible in the demos at the Canon show in Hollywood last month. Canon people admit that the lens has CA. I bought the H1 knowing that it had these problems.

I am convinced that the people that overlook this ugly characteristic of the H1 use low resolution monitors so that the files they view are scaled to lower resolutions which tends to mask the CA problem somewhat. I use a Dell 24 inch 1920 x 1200 monitor and am very critical of my work. Afterall, I am betting the reputation of my company and spending a ton of money for our Indy. I also recognize the problem for what it is, rather than making excuses for Canon.

All of Steve Dempsey's clips on this board show CA problems (red and green fringing on all sharp high-contrast vertical edges, especially in his rowing example where it's hard to see the fence in the background because the CA obscures it, in his shots of the lighthouse where the vertical edges and the verticals on the guard rail on the lighthouse. I downloaded his finaljourney1.m2t file but I can't find it here anymore. However he provides a link to a .wmv file with essentially the same content with a couple of changes. However he changed the intro in the .wmv version of this of the clip. The CA is severe on the edges of the branches in the pine trees on the right and left thirds of the screen. It's really quit obnoxious to look at. Check this link out http://media.dvinfo.net/xlh1/journey1.wmv. It's 200 megs but it's well worth the download. Steve's shoots are very high quality.

These clips are perfect examples of how Steves craft is thwarted by the problems with the H1's lens. If this footage was reviewed by a typical reviewer, on a 50 foot screen at Sundance or whatever, the movie may would be panned for quality reasons. And Mr. and Mrs. John Q. Public, would see the CA in the opening movie sequences. They wouldn't know that the H1 has lens problems. They would, however, wonder what the red fringes around the trees were all about... if that was some sort of an effect or something to degrade the image. I will also tell you that if you view this 1080i footage in Windows Media Player, at something other than full 1980 x 1080, the red fringing is still visible but it is not as prominent because of scaling to the lower resolution.

Steve's footage is great and his shots are well done, but the CA is so pronounced that I wouldn't consider using the H1 for film outs at all without a new lens. However I bought the H1 specifically for an Indie we will be shooting. All I need is a great lens to go with the H1's great body.

In Adam Wilt's H1 review for DV.com, he states the following:

"The stock 20 X lens makes crisp pictures with a minimum of distortion. Its 5.4 mm wide angle is comparable to 6 mm on a 4:3 1/3-inch camera (the Z1 zooms out to 4.5 mm and the HVX goes to 4.2 mm), so it's not the best for tight quarters, but its 108 mm telephoto is hard to beat. The lens shows a bit more chromatic aberration than its competitors, mostly as red fringing at wide angles. Maximum aperture ramps from f1.6 fully wide to f3.4 at full tele. There's some portholing (faint vignetting) in telephoto at apertures wider than f4. There's no focus breathing. M.O.D. at full tele is just over 3 feet.

You can read this review on dv.com. This is the link: http://www.dv.com/reviews/reviews_item.jhtml?articleId=184429497

In the Texas Shootout which was conducted by Adam Wilt with help from Chris Hurd, Adam Wilt compared the HVX, the Z1, the HD100 and the XL-H1. The photos of the skyline with the buildings and the vertical light pole in the background show signs of have CA (red and blue fringing on the vertical edges of the buildings is very pronounced and the light poles also show fringing). I might also add that in this comparison of similar shots with all 4 cameras, the H1's CA was the more noticable than it's lower cost competitors. See this photo for an example of the H1's CA: http://i.cmpnet.com/dv/magazine/2006/June/TX-61-XLH1.jpg. And in the similar Z1 photo in the shootout, CA is practically non-existent. Visit this link to see the Texas Shootout and take a look at the images from the other 3 cameras.

In Scott Billups comparison of the H1, the F900, and the Viper, the H1 fared very well, but in the side by side clips of the the cars. there is very noticable CA on the edge of the right-front tire (green fringing). Take a look at this image at full resolution 1920 x 1080 resolution, not scaled down: http://www.cinematography.net/hdcamtests/pixelmonger/_CAR_2.jpg.

To read the comparison, visit this link: http://www.cinematography.net/hdcamtests/pixelmonger.htm.

I am the proud owner of a great Canon XL-H1, I also own a Sony Z1. The XL-H1 has many benefits and features that I was willing to pay for, but I am not in denial. I am able to at least admit that this camera has lens problems. I sleep well at night knowing that I can ditch the 20x lens as soon as Canon releases their 6x manual lens in October.

I am more interested in ways to solve or workaround the problems with the 20x lens, rather than denying that the problem exists.

I love my H1, Dave.

--Dave

Dave,

If you love your H1 then you must be prepared to live with its limitations. One of those is chromatic aberration at the level of around a pixel near the frame edge. In buying a 10K camera you should expect to have CA at about that level or worse (and there may well be combinations of zoom, aperture and focus distance where it is worse - I only measured a couple of random settings). In making the buy decision you should have considered that this is not a movie camera; it's a TV camera (HDTV - granted) and that in TV the audience is not expected to sit close enough to the screen that flaws at the level of a pixel are noticeable or certainly, at least, not annoying. This fact is exploited in the design of the camera and in the way it stores the video it records and in the design of the TV sets upon which that video is displayed. If you or your audience is sitting close enough to the screen that the CA is problematical then there is very little you can do. Obviously you can invest in a 50K lens which should get CA down to the sub pixel level and try to adapt it to the camera or you can shoot with primes which inherently have better CA or you can use image processing to reduce the CA (works to some extent for lateral but no effect on longitudinal). But the main problem is that if you want or need CA at the level of a 35mm camera with Cooke primes you've bought the wrong camera. The H1 isn't designed to do what you need it to.

And you can explore the possibility that a lot of the phenomena that people ascribe to chromatic aberration isn't and try to find ways to mitigate what you see that you don't like. In the example that started this thread the problem appears to be poor focus and excess sharpening. Turning down the sharpening may be all it takes to make it go away. I notice this kind of fringing with the H1 all the time and on broadcast HD programs as well. As neat at 1440 x 1080 may be it's not really very high resolution. A lot of the apparent resolution comes from sharpening and sharpening works by exaggerating the areas around edges.

Generally speaking flaws at the pixel level in a system that has fundamental color resolution of 4 pixels should not be clearly visible at normal viewing distance but under the wrong circumstances they can be. In looking at the journey1 clip I spotted a fringe that is probably CA in one scene but only if my face is right up against the screen. At reasonable viewing distance I can't see it. Maybe it's time for me to get my glasses prescription renewed. Beautiful stuff, BTW.

The fringe around the auto wheel is unlikely to be chromatic abberation for a couple of reasons: First this looks like the crop from the center of a frame and chromatic abberation manifests itself at the edges of a frame. Second, CA fringing is either red or blue depending on whether CA has been under or over compensated in the lens. And so on.

But rather than try to convince anyone that defects are or aren't CA I think the best I can do is advise people to try the test with a lens that they know has good CA. I expect many of the phenomena attributed to CA will still be seen and if that is the case only disappointment is to be expected in fitting a more expensive lens to this camera. OTOH if you like what you see then that lens may be a good investment.

A.J.

There seems to be alot of chroma abrasion with the default canon lense, thats not cool... any ideas? this is not my footage, And I cannot seem to find any noticable chroma abrasion in Dempsey's work.

here is an example of what i'm talking about.

http://img70.imageshack.us/img70/2486/bluelinesov3.jpg

A 7 day new boot posting a negative comment about a camcorder. First, the shot does not even look in focus which will make it look the way it does, and second you can't even be sure whos footage it is right! Third what is the compression used to show us this HDV footage on DV equipment? Put one in YOUR hands and try it out.

We don't need camera bashing, on any brand, we need useful information, contributions, and discussions. What camera do you have or are you in the market for right now? Where are you located, what do you do for a living, what equipment do you own and use. We post our profile for a reason.

I don't mean any offense, just that we need useful information to comment on and I don't think this is it.

Mike

Hello A. J., Thanks for your response.

The CA I was refering to in the examples I provided go way beyond the 1 pixel level. The examples I provided have Big CA problems, not 1 pixel problems. This 1 pixel statement seems to be an attempt to minimize the problem, and reflects the pervasive denial on this board that the H1 has problems with it's 20x lens. The problem with Canon's lens problem is that there is only one lens to choose from. It's kinda like voting for Sadam Hussein or Sadam Hussein. I wonder who I'll vote for.

One guy on this board even told me that I should just go ahead and switch the lens with a different one and I wouldn't have the problem anymore. But the problem is that there is no other HD lens available for the H1 that I could to switch to. Therefore it's kind of like a love it or leave it mentality that leads to statements like you shouldn't buy the Canon because you wouldn't be happy with it (but under the writer's breath he is implying that I am crazy and that the H1 is too good for me). Or it's only a $10,000 camera. But my Z1 doesn't have the CA problems that the H1 does.

IMHO, H1 owners on this board tend to minimize the CA problem because they don't see a way out of the dilema of only having ONE lens to choose from. Hense they try to talk the CA problem away.

Users of the HVX tend to do the same thing on their board because they can't remove the lens and get a better one. Z1 users seldom complain about CA because there is very little CA to complain about compared to the HVX and the H1. So H1 and HVX users try to talk the problem away rather than dealing with it and talking about it openly. The H1's CA problem is almost a dirty little secret on this board and in the H1 community. When a reviewer mentions it they say he's crazy or he doesn't know what he is talking about. In other words they go into denial.

It's interesting that you should mention the argument that you get what you pay for in lenses so-to-speak. The new Sony XD-CAM PDW-F350 with the standard Sony 1/2" lens offering (which goes for roughly $32,000) has what I consider to be a great deal of CA. On the other hand, my Z1 (costing less than $5,000) has much less CA than the H1 or the PDW-F350.

I think that Canon failed to live up to their reputation with the 20x lens they ship with the H1. And I'm not afraid to say it, even though I own an H1.

The examples I provided had CA substantially greater than 1 pixel. They are more like 3 to 5 pixels on each side of the hard edge (6 to 10) in some cases. And the problem is that when you blow the image up on a 50 foot screen at Sundance, those pixels become huge. In the final journey opening shot (I provided a link to in my previous post), the CA was big and became enormous near the edges of the screen.

The 20x lens has too much glass. Canon tried to make a one size fits all lens. For television, the output is probably ok, but at Sundance it is not.

Again I am interested in a new lens that reduces the CA problems to a minimum. I am not interested in trying to minimize the problem by trying to talk the CA away. I don't use the H1 for broadcast or television work. I am concerned specifically with 24p output to the HD SDI port directly to a Wafian drive which extracts the 3:2 pulldown and stores true 4:2:2 output at 24p.

We use 35mm prime lenses and a cinema adaptor on the H1 for much of our work, to obtain shallow depth of field. I am much happier with the results using the 35mm lenses and a cinema adaptor, and utilizing the 20x lens merely as a relay lens for the cinema adaptor. That way I am only using the 20x in it's sweet spot where there is no CA to speak of.

When shooting with 35mm prime lenses and a cinema adaptor, and utilizing the 20x lens as a relay lens, the CA is negligable. Our 35mm primes don't have the problems with CA that Canon's multi-element 20x lens has.

I would like to use the new 6x manual lens, which I am hoping has less CA for work that doesn't require shallow depth of field. I rarely use high telephoto or wide angle lenses for the kinds of things I shoot. I use mainly 35mm type high-speed (2.8 or faster) primes of 24, 35. 50, 70, 105, 200, and 300mm. However I rarely use the 24, 35, 200 or 300mm lenses in film work.

The H1 works very well with these lenses and I hope that the new 6x manual lens works even better.

In any case, I love my H1 and I will love it even more when I can ditch the 20x lens and use the 6x manual instead. I would like a 12x manual but I don't think there is one in the works. When I need shallow depth of field, I use 35mm prime lenses and a cinema adaptor and the H1 does this very very well in 24p.

I love my H1, Dave.

There are now two images available

www.luontovideo.net/HDV.tif

and

www.luontovideo.net/ProspectHD.tif

which are exported frames from a XL H1 HDV signal and XL H1 Cineform ProspectHD compressed HD-SDI signal, respectively. If nothing else, the images demonstrates the additional details one is able to get with ProspectHD.

My aim was to generate an image demonstrating the effect we are talking about, but, in fact, I failed. Even there is direct light from the window almost against the camera and reflections of the light -which I thought to be sources of difficulties- this time the purple or greenish border did not strongly appear. Still, the effect A.J. is talking about is visible when the images are examined more closely. For instance, look at the leaves or at the light reflection on the table. So, not much to add on the discussion. But, will try again later.

Out of curiosity I went to the TX-81-XLH1 image and measured the CA on the left edge of the building on the far left. It is 1 pixel in the red. No CA (shift) between green and blue. Now what is there that is several pixels wide is the "feathers" from putting both fields into the image. In order to measure the CA I took one field out (and replaced it with a copy of the other field). Now I agree that this feathering is visible at normal viewing distances and is annoying but it is not CA and thus this becomes a perfect example of what I am talking about: people calling artifacts CA for lack of anything better to call them. I suppose you can call it anything you like but if you assume people are dying from malaria but it's really dengue giving them quinine isn't going to solve the problem.

Perhaps it would be helpful if folks looked at some images that are showing strong CA. There is one at http://en.wikipedia.org/wiki/Image:Chromatic_aberration_%28comparison%29.jpg
and http://www.wetpixel.com/i.php/full/correcting-chromatic-abberation-using-adobe-photoshop-cs/
has another screaming example along with instructions on how to fix it using Photo Shop (but don't get too excited - the fix isn't practical for video).

Lauri,

If you want to see CA put the edge (leaf against window) at the edge of the picture. As the H1 seems to have about 1 pixel's shift at the edge it would be about 1/2 half way to the center and less than this closer in.

I have provided links to 8 files taken from finaljourney1.m2t. The link I provided to finaljourney1.wmv on this thread is the same as the .m2t file, but with some changes made at the beginning.

These are glaring examples of CA which would be intolerable in a production intended for projection on a 40 or 50 foot screen, either by a filmout or from high quality HD footage from an HDCAM tape of from a file server. The images were taken from only one clip posted on this board. There are countless hundreds of examples of CA (what I call severe CA) problems in the dozens of files uploaded by other users to this board.

I'm not quite sure why people can not see this CA problem. The H1's CA problem is severe enough, IMHO, that it could be used as the signature or fingerprint of footage shot with an XL-H1. By simply viewing the file it is possible to determine whether it was shot by an H1 or another camera, in my case, a Z1U.

On my hard disk I have many files created with the H1 as well as other HD cameras. I use both an H1 and a Z1U. I have not provided stills or clips of footage I have shot to remove the possibility of the obvious retort from other users on this board that the problems I am describing are unique to my camera and are caused by a bad lens that is in need of service. My H1's lens has exactly the same problems as all the other Canon H1's, and has what I refer to as the XL-H1 "CA fingerprint."

I made reference only to clips posted on this board that others have oggled over and compllimented the shooter for the quality of his work. Showing the problems in files uploaded by other users to this board is a way users may be able to see what they have been overlooking due to inexperience or lack of adequate monitoring facilities.

The typical LCD rear-projector big screen image is so low in resolution and so soft that it is hard to tell the difference between an SD or HD image. Plasmas are much better, but hi-res 1920 x 1200, or higher, LCD display monitors like the one I use, show every flaw in the footage.

In any case, these are the links to stills taken from the file, finaljourney1.m2t, which was uploaded to this board by Steve Dempsey. This is no criticism of Steve's work. I feel that Steve's work is first rate. I marked instances of CA in red. There are more examples of CA in most of the files but I would have run out of space to mark all of them. There is more CA in other scenes in the clip, but these should suffice for the purposes of showing you what CA, or whatever you want to call it, is.

http://hideffilmmakers.com/XL-H1_files/Image1.jpg
http://hideffilmmakers.com/XL-H1_files/Image2.jpg
http://hideffilmmakers.com/XL-H1_files/Image3.jpg
http://hideffilmmakers.com/XL-H1_files/Image4.jpg
http://hideffilmmakers.com/XL-H1_files/Image5.jpg
http://hideffilmmakers.com/XL-H1_files/Image6.jpg
http://hideffilmmakers.com/XL-H1_files/Image7.jpg
http://hideffilmmakers.com/XL-H1_files/Image8.jpg

Note: If you look at these files with monitors at anything other than full resolution, the CA may be difficult to see because the image is scaled down significantly, especially if you look at the images on a low-res 1280x1024 anybrand monitor, scaled by the display software.

Note: If you view these files using IE (Internet Explorer) with a monitor with a resolution less than 1920 x 1080, IE scales the photo down to fit the browser window. This viewing method is inappropriate for judging the quality of footage shot with any HD camera.

Note: Most shooters I know are shooting in 1080 Hi-Def but monitoring with SD 480i or Low-res HD 720p displays. It's no wonder that some shooters can't see problems with their footage, or for that matter can even focus the camera properly. For our shoots, we use a camera assistant to pull focus with a REAL focus puller on rails, (sometimes with a remote) with a matt box, 4 x 4 filters, 35mm lenses with a Cinema adaptor. We take focus and rack focus seriously. We use 4:2:2 HD SDI and take our work very seriously. The H1 has it all... All the features that make a filmmaker happy (or at least the most for the price.). It's hard to know what you are shooting if you can't see it.

Note: The point of viewing Hi-Def footage is viewing it on a Hi-Def monitor or TV. Most of the LCD rear-projector big screens, DLP LCD, LCD or Plasma Monitors sold in the last 5 years are low-resolution, 1280 x 720 (720p) monitors and are inappropriate for QC'ing HD footage.

Note: It's only been within the last year or so that HDTVs have had the capability of displaying 1080 footage natively (true 1920 x 1080). In the future, everyone will have these hi-def monitors, but it is encumbent upon us to use them to truely see our work, and make the appropriate corrections NOW rather than being slammed for quality issues later down the road when your kid has a hi-res 1920 x 1080 HD monitor built in to his alarm clock. Time marches on but your footage can never be re-shot once you ship it.

After looking at these files, at full resolution (that's the way customers will see the movie, either on the movie screen or played with an HD-DVD or Blu-ray disc player), and seeing the CA (or whatever you choose to call it, since it's bad no matter what it is called), it would be hard for any DoP worth his salt to give the H1 a pass for film production unless Canon does something about the 20x lens.

I need a decent lens to finish my work. Most footage shot with the Canon and the 20x lens exhibits some signs of CA. Some shots are worse than others. For shots where the contrast is high between the background and the object or contrasty shadows even on human skin, the CA is pretty bad IMHO.

For shots taken which require shallow depth-of-field, I already have a great solution which is attaching a Cinema adaptor and 35mm lenses to the H1 and using the 20x lens merely as a relay lens to the adaptor. This solution is used in most of my shots and shows little or no CA because the 20x lens is used merely as a relay lens and takes advantage of the sweet spot in the H1's 20x lens. But for outdoor shots, landscape shots, shoulder shots. run-and-gun shots, steadycam shots, etc., I need a good lens without the CA that is so prominent in footage shot with the H1.

I still use my Z1U for this footage and will continue to until Canon comes out with a better lens. Currently, I intercut Z1U footage deinterlaced and converted to 24p using Magic Bullet and After Effects, with footage shot with the H1 and for all shallow depth-of-field shots. The footage works fine together but the the Z1U footage needs massaging and color correction because of it's more video-like appearance.

I love my H1, but I dislike the 20x lens a great deal and hope they introduce the 6x manual lens soon. I also hope that the 6x manual lens lives up to Canon's reputation for high quality lenses.

--Dave

Dave,

I'm rather picky when it comes to this stuff, but -- with all due respect, this is pretty minor, compared to how some of the others perform, and most especially given the price tag. A 20x zoom on a camera for under $9,000... there does come the point where you have to say "you get what you pay for." (I mean, don't get me wrong, I *hate* the lens controls on the XLH1, which is 99% of the reason I haven't bought one; if it had a true manual HD lens I'd probably have one by now). But this C.A. you've pointed out is no worse than any of the other under-$10,000 HD cameras, and far and away better than what the JVC suffers from.

Let's put it in context -- have you seen some of the shots from the JVC? Look at this:

http://www.ideavideo.fi/pic/harakat_hdv.jpg

That's from DVInfo member Jari Pakkanen. Now obviously that's extreme, here's an example I shot with the HD100:

http://www.icexpo.com/JVCnDVX/HD100-Strip-2.JPG

In both those examples I think you'd agree that the aberration is extraordinarily worse than anything in Steven's XLH1 video. And that's not to say that every JVC shot suffers from it to that degree, obviously, but I'm just pointing out what a "bad" example looks like, to keep the XLH1's shots in context.

I think the Z1 and the HD100 are far worse than the HVX and XLH1 in the chromatic aberration department. Simple fact is, they're all going to have some, to some degree or other, especially at the more telephoto settings. There's a reason the CineAlta is $160,000 (with lens) and the XLH1 is $8999. You have to be willing to accept some sort of compromise at this price point.

This is not to diminish or minimize your dissatisfaction, but merely to put a little perspective on it. These cameras are 1/10th to 1/20th the cost of what we've been used to (CineAlta, VariCam, etc) yet deliver images that are well above 1/10th the image! Some CA is going to come with it.

Dave,

What you demonstrate is precisely the same I've found the fingerprint of XL H1, and like you, find it bit repelling. The question is, what causes this, and what should it be called. A.J. says CA is not the right name for the artefact.

To check the effect of the lens, I checked my archives. Here are two frames of HDV footages taken almost immediately after each other.

www.luontovideo.net/Common tern XL H1+20x.tif
www.luontovideo.net/Common tern XL H1+EF600mm.tif

The other one is with the standard 20x lens, and the other is with the EF-adapter and Canon EF 600mm F 4.0 L IS USM lens (a very good and expensive lens).

Interestingly enough, the one shot with the EF600 lens does not seem to have this "border effect" whereas the frame taken with the standard 20x suffers a bit for it (see the top of the head of the common tern).

This is not to diminish or minimize your dissatisfaction, but merely to put a little perspective on it. These cameras are 1/10th to 1/20th the cost of what we've been used to (CineAlta, VariCam, etc) yet deliver images that are well above 1/10th the image! Some CA is going to come with it.

Hi Barry. and thanks for your response.

I already know that my standards are much higher than those of most of the users on this board.

I attended the Canon show at Paramount Studios in Hollywood last month. Canon pedals the H1 camera as suitable for filmmakers and broadcast professionals alike, and yet the 20x lens is second rate compared even to the Z1 which is much cheaper.

I rejected the HD100 and the HVX, out of hand for the CA problems and also because they were the lowest resolution of the bunch.

JVCs offering is only 720p which may be ok for broadcasting, but most filmmakers these days edit in 2K and 4K. Some cameras now originate at 2K and 4K like the Dalsa.

The Sony HVR-Z1U does not exhibit this obnoxious red and green fringing around objects to the same extent as the HVX, the HD100 or the H1 do. I know because I own a Z1U and use it all the time. However it is not ideal for my purposes either.

I don't think my complaints are unreasonable. I have every right to complain about spending $9.000 for a camera that ships with a substandard lens. I am a filmmaker and am trying to make the best product I can.

I am looking for solutions to the problem and have found some, at least as far as using 35mm lenses and a cinema adaptor is concerned. I am waiting for the 6x manual lens to solve some of the other problems I'm having with this over-glassed, underfeatured, be-all-end-all 20x lens.

I won't settle for a substandard lens bolted to the most expensive of the low cost HD camcorders, unless I have to.

The H1 is a great camera and shoots at 1080 24p. It is definitely, by far, the best camera out there in my price range. The H1 is a filmmaker's dream. The only thing that stands in the way of this camera is the lens. Canon is aware of the problem and is attempting to address it this fall with a new lens.

Let's see how well they do with their new lens.

In any case, I love my H1, and very much dislike the 20x lens.

--Dave

Dave,

What you demonstrate is precisely the same I've found the fingerprint of XL H1, and like you, find it bit repelling. The question is, what causes this, and what should it be called. A.J. says CA is not the right name for the artefact.

To check the effect of the lens, I checked my arhives. Here are two frames of HDV footages taken almost immediately after each other.

www.luontovideo.net/Common tern XL H1+20x.tif
www.luontovideo.net/Common tern XL H1+EF600mm.tif

The other one is with the standard 20x lens, and the other is with the EF-adapter and Canon EF 600mm F 4.0 L IS USM lens (a very good and expensive lens).

Interestingly enough, the one shot with the EF600 lens does not seem to have this "border effect" whereas the frame taken with the standard 20x suffers a bit for it (see the top of the head of the common tern).

Hi Lauri, and thanks for the stills.

I guess you are as picky as me. It's not popular being picky around here. Most H1 owners seem to be a little sensitive about their purchases. Maybe it's because there is a problem and they don't like to admit it. It's kinda like buyers remorse. Don't remind me about the problems because I just refinanced my house to pay for this camera.

Well Adam Wilt of DV Magazine is a professional. He has reviewed the H1 and MC'd the Texas Shootouts. He calls it like it is. He states that the H1 has more CA (sometimes he also calls it red and green fringing too) than it's competitors.

I guess Adam Wilt doesn't post on this board or he would be torn to shreds by beginners with buyer's remorse. I am 55 and cut my teeth on film cameras. CA is CA, and it always will be. It is caused by bad lens designs.

Visit this link to see what Canon has to say about Chromatic Aberration: http://www.canon.com/bctv/faq/chrab.html

In the article Canon talks about which types of lenses are most prone to CA problems. This is what Canon has to say:

"In a long focal length, high zoom ratio lens, chromatic aberration is the greatest problem, particularly the secondary spectrum, which is a high order chromatic aberration."

Canon explains the problem and tells us why the H1's 20x lens has CA problems, all in one sentence... "Long focal length, high zoom ratio telephoto lens." IMHO, there's too much glass, too many useless features, and no manual controls. Canon is breaking all their sacred rules to produce this lens, and we pay for the marketing department's overexuberence, trying to outdo Sony and the rest.

I'm not sure what to do about the lens problem except to wait for Canon to come out with a better lens.

I use 35mm lenses and an M2 cinema adaptor on my camera. I love these simple, high-quality 35mm lenses. They are fully manual, sharp, time-tested, predictable, durable, and optically superior to the lenses used on 1/3" CCD cameras. These problems, CA and the like, don't show up when I use this 35mm lens and Cinema Adaptor combination, and is the only way I can use the H1 at this time. I wouldn't put my name on shots filled with this level of CA, or whatever you want to call it, that the H1's lens has. As I said earlier, Adam Wilt calls it CA.

I will say, however, that the shots with the 35mm lenses and shallow depth-of-field are amazing.

I hope that Canon comes through with a new lens.

Thanks again.

I love my H1, but I dislike the 20x lens.

--Dave.

what I dont understand is how my nikon d70s is capable of putting out image quality beyond beliefe..... with absolute 0 chroma abbrasion, and is capable of maintaining 3 frames per second, cant they just work from there and put it up to 24 and 30 frames per second? even if it meant No audio thats fine with me, foaley works wonders. It has to be possible...

what I dont understand is how my nikon d70s is capable of putting out image quality beyond beliefe.

Which 20x zoom lens did you test on your d70?

Best,
Christopher

just the default 67mm Nikkor lense

Is the abberation due to the fact that the lense is 20x? or just poorly made?

because there is practically telescope lenses that can zoom into anything from far away, and they don't have this issue..

this is how images would look at digital slr quality @ 1920x1080.

http://img83.imageshack.us/img83/1885/yardsummer1080pjl5.jpg

http://img56.imageshack.us/img56/1967/yardwinter1080pcx9.jpg

http://img218.imageshack.us/img218/1739/afterrain1080pwi9.jpg

personally I think it's a canon issue with their lenses, because my friend just bought a 20D and almost all his outdoor pictures have chroma aberration issues, not quite as severe as the H1 tho.

example to backup my statement, cropped from an 8MP 20D image.

http://img98.imageshack.us/img98/9607/chromatic1mb7.png

For a digital SLR of it's price range, that is Unacceptable and I will stand by that till the end.

My D70s has no CA issues period as you can see in the above links I posted.

personally I think it's a canon issue with their lenses, because my friend just bought a 20D and almost all his outdoor pictures have chroma aberration issues, not quite as severe as the H1 tho.

example to backup my statement, cropped from an 8MP 20D image.

http://img98.imageshack.us/img98/9607/chromatic1mb7.png

For a digital SLR of it's price range, that is Unacceptable and I will stand by that till the end.

My D70s has no CA issues period as you can see in the above links I posted.

Hi Curtis,

You're on the right track. There is no excuse for the levels of CA on the H1 other than poor design. However I will give Canon this. They know how to make a good lens. The problem with the H1's 20x lens is that they tried to out do their competitors hoping that the typical user would not know the difference. They have proved it to me since the typical user on this board doesn't even know there is a problem, or if he does, he's not willing to admit it.

In an earlier post in this thread, I provide a link to Canon's website in which they explain what CA is, and they cover the types of lenses that are most prone to CA problems. They describe the H1's 20x lens perfectly.

They admit that these lenses have the most CA problems and yet they ship them because inexperienced consumers think they need them. They just see the 20x on the lens barrel and say Wow! Then these guys (and gals) go and make a 480i SD DVD of their kids at a birthday party and say the camera is amazing.

Many of the users here bought the H1 camera to create SD video. That's what the XL1 and 2 are for and you can save a lot of bucks and grief if your go with the XL2, or one of the cheaper Sony HDV cameras, at least until the software companies work out all the bugs, and Intel triples or quadruples the speed of the processor. The Mac uses the Intel chip now too.

Well there are also some serious pros on this board that recognize the problems. Maybe one of them will speak up, but I think that most are afraid to say something because old-timers and beginners alike will come down hard on them for even daring to discus the problem openly. The hostile reply you received from one of the old-timers on this board is a perfect example of what I am speaking of.

How dare you criticize my camera, you, you, you, you newbie! How dare you!

In any case, you are on the right track. However, high telephoto zoom lenses like the H1's 20x lens do have more CA problems than the lenses you are testing on your still camera. Canon knows this but built one anyway, knowing there would be problems. To give Canon credit, that's what the 6x lens is all about. But the typical user on this board probably scratches his head and can't understand why someone would want a 6x manual lens in the first place.

I'll bet that Canon will offer us one of the best lenses out there just so they can address the filmmaker market, and shut people like me up. I couldn't care less about a 20x lens. I'm not interested in shooting butterflies at 200 yards. All I want is a sharp, clean, high-quality, fast manual lens with minimal CA, to complete my film.

Canon probably decided on a 6x manual lens because they know that at that level of magnification, they are able to design a nearly perfect lens, or the next thing to it.

Marketing people at Canon probably don't know how to sell a 6x lens or why someone would even want one, but the engineers know what filmmakers want. I'll bet Canon will build a great lens, once they put their minds to it. That's what I'm waiting for.

For me, this 6x manual lens could be the perfect lens, if Canon designs it well. They certainly know how build great lenses.

--Dave.

I agree whole heartedly, 20x is just simpley not needed for 98% of film making, And I sure is hell wont need that for what I have intended lol...

Any idea what Canon has in store for the H1 exactly? I will take a 6x of pure quality anyday before a 20x that suffers severly from Chromatic Aberrasion. I am very picky when it comes to quality, and when I see severe CA, the first thing that comes to mind is one of those cheesey $80 dollar compact digital cameras, or a cell phone cam... so that's not cool having that in a $9000 dollar professional HD video camera.

I also hear that you can equipe the H1 with Anamorphic 2:35:1 Panavision Primo lenses, however you have to rent them as they are not for sale anywhere on this planet.

Any ideas?

Dave: What you say is true, the 20x lens is not what it should be. But, and I told this to a Canon rep who called me just last week, we bought a camera with interchangeable lenses - why? so we can CHANGE the lens.

Unfortunately Canon has not supported this camera (yet) with accessories (lenses or viewfinders) that will satisfy professionals.

In my case, I've just ordered a 16x manual lens, which is not optimized for HD. Will it have as much CA? Probably. My reason for needing it is that the HANDLING of the 20 x is abominable, not unlike the snowman.

It focuses sluggishly and the autofocus is a joke.

In my case, I'm 62. I went to UCLA film school in the 60's and have shot with every kind of camera except IMAX. I make verite style documentaries and use a lot of filters (like ProMists), so lens optical imperfections aren't as objectionable to me as some others here. Hell, as I've said elsewhere, I've used Pan Cinors, Angenieux 12-120s and Zeis 10-100s (a very expensive BAD lens)...

But - Canon has got to improve this option, THEY MAKE VERY NICE SUPER16 LENSES!!! Even if the lens alone costs $10,000 there are people who will want/need/buy it...

We're still living with a 1/3" chip, though - oh well...

just the default 67mm Nikkor lense

That is the answer to your question, "I dont understand is how my nikon d70s is capable ..." There are other differences between your SLR and XLH1 such as three sensors vs one sensor, sensor size, etc, but the basic difference addressing your CA question is the lens. A 20x zoom has many compromises compared to a prime. That is why you see some XLH1 owners begging for a new lens with less zoom range. Everything else being equal, less zoom range generally means better images within that reduced range.

Best,
Christopher

For a digital SLR of it's price range, that is Unacceptable and I will stand by that till the end.

My D70s has no CA issues period as you can see in the above links I posted.

What lens was used on the 20D. Was it comparable to the Nikkor prime used on your camera?

Best,
Christopher

What lens was used on the 20D. Was it comparable to the Nikkor prime used on your camera?

Best,
Christopher

it was default shipped with the 20D, my lense is default as well.

I think some people are expecting too much from an all-in-one zoom lens that is fairly cheap. The more glass elements in the make-up of a lens, the more problems will need to be overcome.

The 20X AF lens is a decent sharp lens, and so is the 16 X MF lens, but both do not match the clarity of my top EDIF Nikkors clamped to the same video body. Colour fringing is one of the biggest problems I've noticed with video zoom lenses, something that is not so evident when I use pro-level SLR zoom lenses on a video camera, and even less evident when I use a fixed prime lens.

Video zoom lenses do have their uses, and the 20X holds a few advantages when shooting some footage (Image Stabiliser, slow crawling zoom, etc) but there are many times when I've wished for a wide fixed manual lens.

If you read through a hundred archive posts on the Canon 3X zoom lens, you'll find even more problems encountered with colour fringing and maintaining sharpness than found in the telephoto 20x & 16X zoom lenses.

I've got a sneaky feeling that the 6X zoom lens that is about to be released will still have some fringing and sharpness problems that are encountered in the earlier zoom lenses. Hopefully I will be wrong – and the 6X lens will be the lens we are all looking for.

I just wish that Canon had brought out a fixed prime wide angle video lens (around 24mm equivalent SLR lens) to fit the XL camera bodies.

I guess you are as picky as me.

Well, in fact, I try to be as objective as possible and to collect facts, but nothing beyond that. My assumption is that professionals are oble to discuss of technical equipments without emotional reactions, which tend only to blur the analysis. For the very same reason I neither take any names as guaranteed wisdom. I would rather understand myself why, and especially, why precisely. From my earlier experience on this forum I've noticed that A.J. knows what he talks about, which is why my default is, he has a point. But, now back to the topic.

The worst example of my own XL H1 HDV footages is

www.luontovideo.net/Hawk owl.tif

and

www.luontovideo.net/Great spotted woodpeckers.tif

is about the same quality. As they stand, one could not edit these to a TV program to be shown by a national TV station. Still, I think, these footages can be saved by proper postprocessing.

After these shots, I spent a considerable amount of time adjusting the custom presets, and the images indeed became (much) better. For example,

www.luontovideo.net/Ravens.tif

Now, although seldom mention on this forum, the XL2 does suffer for similar kind of problems. Putting the camera in extreme conditions will reveal the problems. For an --this time I guess real CA-- example, see

www.luontovideo.net/Willow tit.tif

If needed I can show much more examples of the XL2 as well.

In any case, I think A.J. has a wisdom when he says one has to accept compromises. Although the marketing machinery lets us understand digital videocameras makes everything only better, this is not quite "the thruth and nothing but the thruth". Often, or should I say in most or in major cases, yes, digital video cameras are amazing compared to the old analog devices, but there is also a cost for the use of compressors etc. Steven Rosen mentioned some time ago on this forum, that the old analog videos seem to have only little artifacts although otherwise they did have shortcomings. That's the same impression I get when looking back to my old Betacam tape archive.

The first aid of "red/green fringing, CA, border effect" --what ever one liked to call it-- were a proper postprocessing filter. Should not be imposible to code a filter to remove the bit annoying effect of XL H1 and it's standard 20x lens. Perhaps Cineform could make a one?

I understand everyone's concern with C.A. but think Dave listed the problem and solution all at once. The XL-H1 is a great CAMERA for (indie) film and TV. The VF blows, but once you get past that (or get an HD-SDI on-board monitor or FU-1000) it's a great camera. Dave agree's other wise he wouldn't post as such at the end of every one of his posts.

BUT, the lens isn't good enough for big screen work. So it goes. Personally I tried to buy my camera without the lens (still isn't an option) because I love the 35 adapters, I love the DOF and I like being able to use more intechangable lenses. That being said how many people out there are using the 20x lens with the realistic notion that it will be blown up to 35?

It's the same old story, no one is satisfied with anything, if they had given us a lens with better C.A. (or less C.A. or whatever) it would have cost more, and people would have said "I'm not spending 10k on an HDV camera". But if they had dropped the price to 7500 and not included a lens (so you could use the 1500 on a 35mm adapter and some lenses, or at least the rental of one...) people would have said "I'm not spending 7.5k for a camera without a LENS!" (even though it does have an HD-SDI output)

For the love of god, HD is not Film, HDV is not HDCAM. All of these formats can be tweaked to look very good, and/or very bad. Dave has found a solution, I find it SLIGHTLY odd that in order to reduce the C.A. on a lens, you have to shoot through that lens and ADD more glass to it, but if it works for him perhaps that's something everyone else should try. For me the Mini 35 or the Letus seems to be a better option, but that's me.

So the lens was a trade off between price and performace, has anyone priced true HD lenses? I'll go one step further and predict the future. When the 6x auto lens comes out (when I saw it at NAB-I know, it was a mock up- it looked AUTO not Manual, NOT like the 16x, or my favorite xl lens thus far the 14x) there will still be C.A. issues, but it'll be better then the stock lens, or at least wider and everyone will run to it and some will buy it then someone will point out something wrong with it and then there will be another thread just like this one. Certain people will weigh in and others will disagree, and at the end of the day no one's opinion will really change.

I don't mean to belittle a problem or anyone's opinion, but if the lens is only going to be an issues on a 40ft screen, uh, don't use it. Use an adpater, problems solved, if it works for TV then use it for TV.

P.S. the 20d stock lens stinks, put a respectable lens on there (24-70mm f/2.8L, 85mm f/1.2L II) an tell me that canon glass stinks...

And for the record, my HDTV is 1920x1080, I have made the money back on my camera (though not all of the accessories) so my buyers remorse has almost past and I'm ready to date again, and most of my work is with the larger format HD cameras (Sony F900, Some Varicam, etc.) not film, so that's my frame of reference. An my backpack's got jets...

This has certainly been a most intersting thread and I wonder if any conclusions can be drawn at this point. I spent the morning looking at lots of the images you guys have posted and I must say I saw just about every kind of defect that video is heir to. Things like plain old aliasing (moire), color noise, DCT roundoff (tiling), chroma/luma crossover, limited chroma bandwidth, "mosquito" effect and artifacts caused by sharpening (halos, color noise) and yes, chromatic aberration as well. I was most interested to compare the frames from still cameras with "no" chromatic aberration to those with "unacceptable" levels only to find that they had comparable levels (about 1 pixel at frame edge). From this I conclude that designers shoot for 1 pixel at the frame edge and in this sense I guess I'd have to say the 20X is OK. That they can hold it to 1 pixel in a lens this inexpensive with 20X zoom range is amazing to me. As I don't want to be thought of as an apologist for Canon let me say that I share most peoples' views about the clumsiness of the thing and difficulty in using it in manual mode. I'd much prefer a 'real' lens (as long as it has image stabilization).

So I guess my conclusion at this point is that there are things about this camera you don't like and that's fine because there are, as Chris put in the Texas shootout summary (I think it was), there are severe limitations in all the sub $10K HD cameras. I agree wholeheartedly with this statement. What I don't agree with is that a magic lens will solve the problem because some of the problems that you have complained about aren't caused by the lens.

I suspect that what may be responsible for many of the problems you are seeing is sharpening. What sharpening does is enhance edges by boosting the video level on the bright side of a transition and lowering it on the dark side. As you move away from the edge the video level transitions back to the level recorded by the CCD. This process puts halos or bands around objects which are certainly noticeable if you are looking for it. There is an appreciable gain in perceived sharpness when you do this is that's why they do it. It's an engineering trade space. People used to scream bloody murder about the aliasing in the XL2. There are, on this board, lots of posts with a similar tone to that of some in this thread - that Canon cameras have unacceptable levels of Moire, that there is no excuse for this.... No one seems to complain about aliasing with the XLH1 which causes me to think that Canon put a blur filter in the optics to control it (and I think they did). As a result the picture is softer than it would be without the antialising filter which would cause people to complain about the resolution of the camera. The fix: sharpening. But nothing comes free. Sharpening introduces the halos and noise I mentioned earlier. Wouldn't it be ironic if Canon responded to complaints of aliasing by low pass filtering and sharpening only to be hoist upon their own petard in this same area of the design?

If my thesis is correct there is a simple fix. Turn down sharpening and see if you like the result better. Halo's will go away but the picture will not be quite so sharp. Dave commented that he liked the result with the 35mm adpter. The ground glass in these adapters reduces the image sharpness somewhat - perhaps enough to offset the sharpening algorithm in the camera. Perhaps reduced sharpening will do the same. Maybe I am right about this, maybe not. What does it cost to try it?

My opinion of the XL-H1: It's miraculous. At the price it's FM! It will put an image on my plasma TV which is better (lots better) than much of (but not all of) what is broadcast. In many cases it's images are better than those of movies presumably shot on 35mm film. It's images are sharper than what I see in the movie theatre in some cases.

Perhaps I am more forgiving than some of you because as an engineer (on the creative side I'm pretty much limited to knowing you shouldn't pan and zoom in the same shot) I have more reasonable expectations on performance given the current state of the art. But you guys are right to keep demanding more. Eventually you will get it but the development cycle can be excruciatingly slow.

it was default shipped with the 20D, my lense is default as well.

That does not identify the lens. You are comparing a Nikkor prime with an unknown, possibly zoom, possibly third-party lens, and then claiming the d70 body has less CA than the 20D body. You might find it useful to read an ariticle on lenses, refraction, and the causes of chromatic abberation.

Best,
Christopher

This is, indeed, an interesting and useful thread. Thanks for everybody.

A.J., I tested immediately what you suggested. The frames are here:

www.luontovideo.net/Sharpness 0.tif
www.luontovideo.net/Sharpness -3.tif
www.luontovideo.net/Sharpness -6.tif
www.luontovideo.net/Sharpness -9.tif

But, also for my surprise, the visual impression is that decreasing sharpness will make the green border line more visible. Just compare the vertical lines between Sharpness 0.tif and Sharpness -9.tif.

Second, while a took the footages, the light turned towards left. Only a moment after taking these images I could no longer reproduce the green line between wall and stairway on the right hand side of the image. This seems to confirm what I've observed earlier: light reflecting back to the lens make the situation worse. (... Well, if there was no light reflecting back to the lens, there were no problems, but the image would also be completely back. So, let's say shiny objects such as metal pipes, snow fields or white walls generate difficulties when the light source is behind the camera.)

...as Chris put in the Texas shootout summary (I think it was), there are severe limitations in all the sub $10K HD cameras.Actually I think it was Adam who said that (and for what it's worth, I agree with him on that point). Adam Wilt and Mike Curtis have provided a lot of results-oriented technical feedback regarding the Texas Shootout, but the role I played in it was that of producer, which was a learning experience all its own.

That does not identify the lens. You are comparing a Nikkor prime with an unknown, possibly zoom, possibly third-party lens, and then claiming the d70 body has less CA than the 20D body. You might find it useful to read an ariticle on lenses, refraction, and the causes of chromatic abberation.

Best,
Christopher

I just asked him what type of lense he received with his camera, and he said it is the Canon 18-55mm EF-S.

The Canon 18-55mm EF-S is the stock lens bundled with the Rebel XT and 20D. I have one. It's pretty much a "freebie" lens in that it has a market value of less than $100. Now it's adequate for what it is, especially considering what it costs, but it is by no means any measure of Canon's true capability with optics. Any other EOS lens is much better than the 18-55mm EF-S.

I just asked him what type of lense he received with his camera, and he said it is the Canon 18-55mm EF-S.

OK, that explains the difference in CA you are seeing. You are comparing a Nikkor prime lens with a Canon consumer zoom lens. Chromatic aberration is caused by a lens having a different refractive index for different wavelengths of light. So, if you see chromatic abberation, it is likely more a property of the lens than the body.

Best,
Christopher

Lauri,

I looked at (analyzed) your images and here's what is going on. Coming out of the CCD red and blue are sampled at a lower rate so that while the transition between the dark area and light area (between stairs area and wall at the right of the picture) in the green channel takes about two pixels it takes about 4 pixels for the red and about 6 for the blue. Thus the first few pixels after the transition (moving to the right) look green in the raw image (no sharpening). When you apply sharpening the green transitions in about a pixel's width as does the red while the blue takes about a pixel and a half. Thus the green band after the transition is narrowed. Note that the blue transition is shifted about a pixel to the right of the red and green transitions. This IS chromatic abberation.

The reason the system is designed this way is because you aren't supposed to to be able to see color shifts of these magnitudes at these rates unless you sit close enough to be able to clearly distinguish individual pixels which in theory you aren't supposed to do. The fact that you can see them either says that you are looking too closely or that you have unusually sensitive color vision either or both of which is possible. Dave wondered why most people here can't see these things. I suspect the answer is that while the whole of color science is based upon the "average observer" you two (and doubtless others as well) are not average. I'm at the other end of the spectrum. To see the fringe clearly at one display pixel per image pixel at comfortable viewing distance I have to boost saturation appreciably (yes I'm a protanope).

So in this case the "problem" is simply that of reduced chroma color bandwidth. It is a shortcoming of the system which is designed in. It should be better with 4,2,2 sampled data from the SDI port (I assume this was an HDV capture) but still not as good as it would be with 4,4,4. With respect to CA we note that while it is there its effect is masked by the color bandwidth limitations. A better lens would not fix it.

As to why this goes away when the angle of the light shifts all I can say is that we now have a whole new situation. Perhaps the contrast is less across that transition when the light is more angled and maybe that is enough to explain it.

Thanks for posting those images. Very interesting! And thanks for your kind words as well. They are appreciated.

So in this case the "problem" is simply that of reduced chroma color bandwidth.Many thanks, A.J., your detailed explanation is much appreciated. Is there are proper term for this issue (and if not, should we come up with one of our own)? Since it has obviously been mislabeled (somewhat vehemently by some people) as "chromatic abberation," it would be nice if we could properly educate those who incorrectly assume it as such. To me, reduced chroma color bandwidth is an accurate description of the cause, but not the symptom itself.

Chris,

from what i've seen so far, from the res charts, the manual lense looks a lot more "solid".

There is almost no CA, and the res is as good as the stock lense.

I think the 20X lense does create some CA.

The 3X is also a lot cleaner than the 20X to my eyes.

A.J.,

Thanks for your excellent analysis. All this makes now a lot of sense.

It should be better with 4,2,2 sampled data from the SDI port

Yes, this is what I said earlier in this thread; When I take the signal from the HD-SDI port, the effect is less visible, which is why I had difficulties to agree with others that the effect is caused only by the lens.

Perhaps the contrast is less across that transition when the light is more angled and maybe that is enough to explain it.

This is precisely the case. Yesterday there was first high contrast across the transition but as soon as the sun turned more on the left the contrast got lower and the effect diminished.

Now, that the issue is understood makes it clear how the custom presets can be exploited to remove the effect -and this vindicates A.J's hypothesis; Instead of setting sharpness I made a new experiment with Noise reduction 2, which I set to "high". The frames are here

www.luontovideo.net/Neutral.tif
www.luontovideo.net/NoiseReduction2.tif

and the green border between the wall and stair way is less noticeable. (I also use gamma set to Cine1, which I've found to help with the border effect. The reason is clear: contrast becomes lower.)

All this makes me now to suspect that the EF-adapter is a kind of low pass filter which acts bit like Noise reduction 2 softening the image. This explained i) why the images produced with EF-lenses seem to have less contrast as if they were slightly grayish compared to the standard 20x lens, ii) why people report "there is less CA with EF-lenses" and also iii) explained why Canon say the EF-lenses are not HD-compatible. The visual impression of XL H1 + EF lenses is though still very pleasing. The moral is, judging images based only on visual examination is very difficult and easily leads to misconclusions. Still, would like to emphasize, the final conclusion is to be made.

Chris,

I'd say we should refer to Lauri's wall problem as the "chroma undersampling effect". Note that I'm using "effect" rather than "problem" because it is there intentionally as part of the design and there are a couple of ways (that we know of at this point) to get around it: increase sampling to 4:2:2 (use SDI), turn on noise reduction, lower contrast (either through lighting or gamma) try to keep strong verticals out of the composition, try to avoid transitions with the bright side on the right...

Or we could call it the "Lauri's wall effect".

Whatever we decide to call it I don't think that is the end of the story because I don't think this phenomenon covers all the artifacts that people have been talking about in this thread. The fact that this particular situation was not caused by chromatic aberration does not mean that the XL-H1 doesn't exhibit some chromatic aberration with the stock lens. It definitely does. Also aliasing, DCT tiling, haloing, and all the other things I mentioned in an earlier post are still being called chromatic aberration by some.

A.J.

... there are a couple of ways (that we know of at this point) to get around it: ...

Adjusting the R-G, G-R, etc. entries of the color matrix help as well. After shooting the www.luontovideo.net/Hawk owl.tif footage, I spent a lot of time adjusting the entries of the color matrix, and after that have not seen the purple borders again. Also the green ones do not appear as often as they used to.

My background is in scientific research, and think it's never a good idea to name something after somebodies name.

Lauri,

The suggestion that we name it after your wall wasn't entirely serious but your comment got me thinking about the names of scientists whose work had some bearing on this problem/phenomenon: Newton (drew the first color wheel), Abbe (quantized the dispersive properties of glass which are responsible for CA), Airy (first Astronomer Royal after whom the form of an ideal lens's image of a point is named), Bessel (for the mathematical function which describes the Airy Pattern), Shannon (whose sampling theorem makes digital video possible), Seidel (who came up with a unified way of describing CA, spherical abberation, coma....) and lots more.

There certainly has been a lively response to this concern about the "stock" lens.. some well informed, some bashing, some defensive...

When I first got my H1 last December I tested it with the 20x and the 16x and preferred the 16x primarily for handling reasons. As I wrote then, I found the 20x sluggish and unresponsive and particularly didn't/don't like the OIS. That was, and still is, my opinion.. I sold the 16x with my XL2, but have just ordered another one, again, primarily because of handling.

But, back to the 20x. The fact is that some really nice images have already been made with this lens (some by me, if I do say so myself).. Overall, I'm not as displeased about CA.. and I do believe that much of what is being attributed to the lens is endemic of HDV and 1/3" chips... So, where does that leave us?

In my case, shooting documentaries, mostely handheld, a small amount of CA, or whatever the hell it is, is not really noticeable at all.. For others, especially those who work w/ green screen or want to shoot pristine nature footage at the long end of the lens, it will be a problem..

I remember the American Cinematographer story over 35 years ago about the production of LAWRENCE OF ARABIA - in shooting that film they deliberately chose lenses with chromatic abberations because they wanted the effect of shooting through hot desert atmosphere - and it's a "look" that has been immulated in many non-desert films since.. Pick the tool for the job.

I'm not excusing Canon for the 20x, I too wish there was another HD lens available for this excellent camera. I'm just saying that used in the right circumstances this little box is a pretty good deal for $9000.

Here here, Steven.

Lauri,

The suggestion that we name it after your wall wasn't entirely serious but your comment got me thinking about the names of scientists whose work had some bearing on this problem/phenomenon: Newton (drew the first color wheel), Abbe (quantized the dispersive properties of glass which are responsible for CA), Airy (first Astronomer Royal after whom the form of an ideal lens's image of a point is named), Bessel (for the mathematical function which describes the Airy Pattern), Shannon (whose sampling theorem makes digital video possible), Seidel (who came up with a unified way of describing CA, spherical abberation, coma....) and lots more.

and don't forget Murphy.

Murphy is almighty, but don't forget Bayer's pattern and Nyquist's limit.

Here's how I knocked down a burning blue ring of fire with a simple custom preset:

http://www.dvinfo.net/conf/showthread.php?t=72218