View Full Version : Red gradient at top of image 110U?
Matthew Rogers May 8th, 2007, 01:01 PM Hey, so I just got my 110U a month ago and have noticed something a little weird... When I use the stock lens and open up more than 2.8f, I get a red gradient on my image. I am not sure if the lens is faulty, or there is something wrong with the CCD's, etc. The specs are JVC 110u w/stock lens and Truecolor 3 settings at 24P.
Here is a still of what's happening and also a .mov of an iris pull to wide open.
Matthew
Tim Dashwood May 8th, 2007, 01:42 PM It is lateral chromatic aberration. You'll notice that the bottom has a green gradient.
There isn't much you can do about it on a HD100 or HD110 except to not open up past f/2, or use a different lens.
I have had some success correcting for it in post by layering the clip with gradated mattes and colour correcting the image in three layers (top, middle, bottom.) This takes alot of work, but there may be some plug-ins somewhere.
The HD200 and HD250 have a 'white shading' capability that compensates for this. Different adjustments are required for different lenses.
http://www.dvinfo.net/conf/attachment.php?attachmentid=373&d=1152554607
Matthew Rogers May 8th, 2007, 01:53 PM It is lateral chromatic aberration. You'll notice that the bottom has a green gradient.
There isn't much you can do about it on a HD100 or HD100 except to not open up past f/2, or use a different lens.
I have had some success correcting for it in post by layering the clip with gradated mattes and colour correcting the image in three layers (top, middle, bottom.) This takes alot of work, but there may be some plug-ins somewhere.
The HD200 and HD250 have a 'white shading' capability that compensates for this. Different adjustments are required for different lenses.
Is this true with all the fujinon 16x5.5 lenses that came with the 100 or 110? (or is it just some of the lenses?) If so, I find that absurd considering that my DVX100A-which I paid only $3,300 a few years ago doesn't have this problem. I was under the impression that CA was the color fringing on edges that you can get when zoomed in--not like a gradient.
It just hurts to pay $5,000 for something that has a glaring color error.
Matthew
Tim Dashwood May 8th, 2007, 03:35 PM Every lens is different so when you use a 3-CCD camera capable of interchanging lenses you may run into this problem. This is not specific to the Fujinon lenses.
The primary reason you are unlikely to see this sort of thing on a DVX100 is that it only ever uses one lens, so the white shading is likely already programmed into the camera for that one lens.
It would have been great if JVC had done this and compensated for the 'stock' 16x lens, but then it may have looked worse with a high quality lens.
JVC addressed this issue with the HD200 and HD250 and added the white shading function, which is not found in any of the 3-CCD cameras in the same price range.
Gary Morris McBeath May 9th, 2007, 10:58 AM Mathew and Tim:
I have the same problem with my 100; it was as you said Mathew with the stock lens. I purchased the 17x lens, and the problem is worse: the red banding is on the top and the green is on the bottom at more that f2.8, but at f4, f5.6, where I shoot, the colors reverse, with the green band on the top and the red on the bottom; it is significant enough that I cannot get a proper manual white balance.
Fujinon service checked out the lens, even gave me another one to try, and both were the same. They indicated it was the camera ccd block. JVC service pretty much alluded to the same, by noting this is part of the shortcomings of a "low end" HD camera. No names here.
So, I'm basically stuck with doing color correction in post, or using the 3200K and 5600K presets. Doesn't always work when you have unusual lighting conditions. Unacceptable for a "Pro" camera. I've been quiet about this for some time, but now that others are experiencing the same problem, I feel compelled to speak out.
Carl, if you are reading this, why wouldn't it be possible to provide us a firmware or software upgrade that would include the lens shading feature the newer cameras have? An upgrade we could do ourselves, perhaps similar to the way we did the upgrade on the BR-HD50 deck? I'd even be willing to pay a nominal fee for such an upgrade.
I have a significant investment in this camera, lens and support equipment, including the deck, and also bought one of the first GY-DV500 cameras 7 years ago. JVC should consider the benefits of taking care of their long term customers.
Well, I'm off my soapbox now.
Thanks,
Gary
Sergio Barbosa May 9th, 2007, 11:16 AM I totally support you Gary... It is in fact a very limiting characteristic of this lens. And as you all said, since this is the stock lens, the camera should come calibrated for it - that's nothing but good sense! A firmware upgrade of some sort that could fix the problem would be nothing but the right thing to do.
Let's see if anyone hears us.
Sean Adair May 9th, 2007, 11:49 AM Gary, I seriously doubt that the white shading feature can be implemented with firmware. I would guess that technician could "tune" the single point calibration though. I assume there is a fstop where balance occurs around 2.8/4 but shifting this wouldn't help you much either.
I've done a setup with my HD200, and made a relatively minor adjustment with the white shading feature. It's generally pretty subtle on my camera, unless the lens is wide open. I suspect other improvements were made as well. The instructions for using the white shading are to set it up at f4 or higher. I notice also that the colors swap with fstop, so I suspect even if you had this correction ability, you would still have issues outside your sweet spot where you set it. Eg - if I disregard instructions, and remove the color at wide open, I see color as I stop down.
I hear your pain, but there is constant development of these products, and that's a good thing. Generally these features are not upgradeable - look at the panasonic DVX100's going through significant improvements in the A and B revisions. With a completely new model, it's not surprising (a good thing!) that improvements are implemted (HD110), and with some improvements, that there is a price to pay (HD200/250). You HD100 adapters were a brave bunch, and I continue to see fantastic results from that camera. There are a bunch of things to workaround though, and the 200 series isn't exempt!
Gary Morris McBeath May 9th, 2007, 02:00 PM Sean,
Good info! Thanks. You gave me an idea: I'll see if there is a "no color fringing" spot between wide open and f2.8 where the colors begin to show again, except reversed. I might be able to get an adequate white balance there. I'll give it a test later this afternoon and post back.
BTW, the green on top and red on the bottom pretty much stays the same from f2.8 on down. And it is so slight, I'd have to be shooting a white wall or snow for it to show, although a sharp eye might catch it in other scenes. But it is enough to cause a poor white balance.
Later, Gary
Matthew Rogers May 9th, 2007, 04:01 PM Gary, I seriously doubt that the white shading feature can be implemented with firmware. I would guess that technician could "tune" the single point calibration though. I assume there is a fstop where balance occurs around 2.8/4 but shifting this wouldn't help you much either.
I've done a setup with my HD200, and made a relatively minor adjustment with the white shading feature. It's generally pretty subtle on my camera, unless the lens is wide open. I suspect other improvements were made as well. The instructions for using the white shading are to set it up at f4 or higher. I notice also that the colors swap with fstop, so I suspect even if you had this correction ability, you would still have issues outside your sweet spot where you set it. Eg - if I disregard instructions, and remove the color at wide open, I see color as I stop down.
I hear your pain, but there is constant development of these products, and that's a good thing. Generally these features are not upgradeable - look at the panasonic DVX100's going through significant improvements in the A and B revisions. With a completely new model, it's not surprising (a good thing!) that improvements are implemted (HD110), and with some improvements, that there is a price to pay (HD200/250). You HD100 adapters were a brave bunch, and I continue to see fantastic results from that camera. There are a bunch of things to workaround though, and the 200 series isn't exempt!
Considering that the firmware is upgradeable on the 100 series, it should be possible. The reason the DVX100 was upgrade with new models is because the firmware was not upgradeable.
This is really an issue that should have been addressed before the first 100 ever shipped. It's not a new problem with cameras evidently, so why is it even considered "okay" to ship without some way to correct it?
Personally, if I could ship my 110u in and have them calibrate it for the stock lens I have, I would be happy. I am not planning on getting a different lens, so I need it to only work with that lens.
This is not a problem I should have to be fixing in post--especially when they call it a pro camera and I am using the camera within normal use (aka, not using 18db of gain in pitch black room.)
Am now waiting for my Red cam to get here with some good Cooke glass...
Matthew
Sean Adair May 9th, 2007, 09:19 PM Considering that the firmware is upgradeable on the 100 series, it should be possible. The reason the DVX100 was upgrade with new models is because the firmware was not upgradeable.
Matthew
Firmware is limited in what it can address. I suspect that there are differences in the electronics allowing this to be adjusted. The point is that the technology is constantly improving, and you cannot change a 100 into a 200 (or even a 110) with mere firmware.
This is really an issue that should have been addressed before the first 100 ever shipped. It's not a new problem with cameras evidently, so why is it even considered "okay" to ship without some way to correct it?
Matthew
I find this logic a bit circular. It's a known issue in other (including more expensive) cameras, and people work around it. The technology to address it I assume took time to implement at this price point.
Personally, if I could ship my 110u in and have them calibrate it for the stock lens I have, I would be happy. I am not planning on getting a different lens, so I need it to only work with that lens.
Matthew
What the adjustment does is set a balance at a center point, but the colors will move in opposite directions from there. The other exacerbating factor is shooting at the extremes of the lens focal length - especially full telephoto. I'm only picking up on mine against a white background at the extremes of fstop and focal length. It's just another thing to learn and work around through steps that minimize it or ways to correct it. High-end cameras have more areas to be careful about than camcorders.
It's like complaining about the air conditioning in my Lamborghini.
(hehe, not mine, but some people do...)
This is not a problem I should have to be fixing in post--especially when they call it a pro camera and I am using the camera within normal use (aka, not using 18db of gain in pitch black room.)
Am now waiting for my Red cam to get here with some good Cooke glass...
Matthew
hmmm. getting touchy here. Getting the best these cameras can deliver requires some dedicated technical cinematography. The 16x lens I suspect needs even more care, and that is where most of the fault lies. If you are shooting against a white background, try to avoid the telephoto range, keep the exposure around f4, and don't use any gain ;^)
and congratulations for joining the ranks on the real BLEEDING edge :)
With the amount you'll be spending, and a new generation of technology, you'll be leaving behind many limitations we face. But I'll be surprised if it's all smooth sailing. I'm always reminding myself what some artists can produce with a pencil when I get frustrated at some equipment limitation.
I'm not trying to get on your case here, but wanted to respond with my POV.
Jemore Santos May 10th, 2007, 05:43 AM I saw the same problem a year ago, much to Tim's advice, I never fully opened the lens, 6 weeks ago an engineer from work went to a JVC repairer conference
and he was given training tools and software on how to repair the ProHD cameras. After giving my camera the latest firmware upgrade, I then had SSE, which was all corrected by converting the CCD's and aligning their FPG's.
Long story short, white blemish is an issue that JVC has addressed, it is the design of the CCD block which can be corrected with firmware/software correction and upgrades.
Marc Colemont May 10th, 2007, 06:32 AM So does it mean that there is the possibility that the HD100 will get this firmware update?
Jemore Santos May 10th, 2007, 06:39 AM My camera is the HD100j, there are several version upgrades, the guy that serviced my camera managed to upgrade me to 2.1 even though it should only go up to 1.9, with version 2> there are certain system patches that will fix problems like white blemmish etc.
Matthew Rogers May 10th, 2007, 12:02 PM My camera is the HD100j, there are several version upgrades, the guy that serviced my camera managed to upgrade me to 2.1 even though it should only go up to 1.9, with version 2> there are certain system patches that will fix problems like white blemmish etc.
When you say version 2> you mean firmware that was ment for the 200/250 series? My understanding of the differences between the 100 series and 200 are a better DA (hardware?) and a better encoder (software?) plus a few other small things. So you had the CA in your image before and now it's gone after upgrading the firmware?
Matthew
Gary Morris McBeath May 10th, 2007, 12:53 PM Well, I just did my test; there is a spot between wide open and f4 where there is no defined red or green band, but instead there are red and green splotches all over the image (shooting white foamcore, lit with 3200K tungsten). still can't get a decent WB. Even tried my warm cards, ctb and +green over the lens, trying to offset the effect of the red and green, but, as Sean had cautioned, the banding or splotching is not consistent with exposure and maybe slightly with focal length, (even when exposure controlled with shutter speed or ND).
Remember, on the stock lens, the banding is only there at f2.8 and open, OK f4 and above. But on the 17x, it is there in some form at all stops.
So I guess if I'm to enjoy the better resolution and refinements of the 17x, I'm stuck with using the internal WB presets, then color grade in post. Or, go to the trouble of switching lens for the white bal, then put the better lens on for the shoot. (which I did recently when shooting under some odd colored flourescent lights.)
I'm still open to ideas.
Gary
Gary Morris McBeath May 10th, 2007, 12:57 PM Just an additional comment: to show how much this red and green banding/splotching is effecting the WB, I will get anywhere from 3200K (looks different from the internal setting) to 3700K, simply by changing the f stop between wide open, f2, f2.8 or f4. I keep the exposure fairly constant with shutter, just below 100% zebras.
Unacceptable.
Gary
Sean Adair May 10th, 2007, 03:49 PM Unacceptable.
Gary
I agree Gary. In this case it really seems like something is wrong. The 17x works well on my HD200. Maybe others with the 17x on a 100 series can chime in. Your camera might need servicing - it seems that there are some updates and calibration that could help.
Gary Morris McBeath May 10th, 2007, 04:27 PM Sean, it would seem so. But I just got it back from JVC service in California, where it was supposed to have been fully brought up to the latest spec while in for another repair.
Before that I tried my 17x lens and the brand new loaner 17x from Fujinon on my cam, and a 200 at my dealer; same problem: each camera/lens combo showed a slightly different red/green pattern, but it was there in all of them.
Maybe I'm destined to work on the Red-Green show on TV; if I held the camera sideways, and just right, I could enhance the color of their suspenders.
Gary
Matthew Rogers May 10th, 2007, 09:54 PM I find this logic a bit circular. It's a known issue in other (including more expensive) cameras, and people work around it. The technology to address it I assume took time to implement at this price point.
The thing is, people DON'T have to work around it with other cameras. Those cameras have the white shading function to correct such a problem. Since this is not an old issue, they should have known how to fix it a long time ago.
The other exacerbating factor is shooting at the extremes of the lens focal length - especially full telephoto. I'm only picking up on mine against a white background at the extremes of fstop and focal length. It's just another thing to learn and work around through steps that minimize it or ways to correct it. High-end cameras have more areas to be careful about than camcorders.
hmmm. getting touchy here. Getting the best these cameras can deliver requires some dedicated technical cinematography. The 16x lens I suspect needs even more care, and that is where most of the fault lies. If you are shooting against a white background, try to avoid the telephoto range, keep the exposure around f4, and don't use any gain ;^)
The thing is, I am getting the red/green at ALL focal distances. I don't understand your logic of having to "put up" with equipment which is not working the way it should. That's why I try to buy "pro" gear so I don't have to deal with stupid, simple issues--like the camera not producing a clean image!! It's a simple issue that should never appear nowadays on a "pro" camera (and JVC calls the 110 a pro camera.) I just feel that a "pro" camera should perform better than a prosumer camera, and right now it's not.
I think this is one reason I am looking forward to the RED cam. They have taken great care in designing a product that is professional in all aspects. They don't seem to be taking any short-cuts or skimping in the design (I see that from them saying, "yeah, we are going to wait a few weeks on the release because we think we can get a few more stops out of the chip if we work on it some more.")
Sure, release a camera with not as many features. However, make sure the image is clean!
Matthew
Sean Adair May 12th, 2007, 09:52 AM Well, I can see that this is frustrating for some people in some configurations. The 200 does allow you to adjust white shading, so it works, and it simply is 2nd generation technology at this pricepoint. Overall, I'm quite please with the niche of JVC's ProHD. There are lots of compromises, and preferential choices to consider at this price range.
I follow the RED a bit as well. It should represent a significant breakthrough in technology. But, you have to order a camera at least a YEAR in advance of delivery, and the delays are not really that specific. (more like: we are not able to meet our claimed quality standard, and production will be delayed for an indefinite period - see www.red.com ). Not to mention the cost for a package with narrow functionality. It really isn't a fair comparision.
I'm interested though, Do you have a link to information about their white shading correction? Given the variety of lenses people expect to put on this unit I'm sure adjustment will be needed - or will that be post workflow?
Matthew Rogers May 12th, 2007, 10:06 AM Well, I can see that this is frustrating for some people in some configurations. The 200 does allow you to adjust white shading, so it works, and it simply is 2nd generation technology at this pricepoint. Overall, I'm quite please with the niche of JVC's ProHD. There are lots of compromises, and preferential choices to consider at this price range.
I could understand "2 generation" fixes if it was a new problem to 100 series only. However, this evidently can be a problem for ALL 3 CCD cameras, and should have been addressed. I'm sorry, but it's labeled as a "Pro ENG" camera, and many times in ENG style you have to shoot wideopen against, gasp..white backgrounds! I'm sorry, I'm just sick of companies not taking pride in their work anymore. It's all about trying to make a quick buck.
I follow the RED a bit as well. It should represent a significant breakthrough in technology. But, you have to order a camera at least a YEAR in advance of delivery, and the delays are not really that specific. (more like: we are not able to meet our claimed quality standard, and production will be delayed for an indefinite period - see www.red.com ). Not to mention the cost for a package with narrow functionality. It really isn't a fair comparision.
I'm interested though, Do you have a link to information about their white shading correction? Given the variety of lenses people expect to put on this unit I'm sure adjustment will be needed - or will that be post workflow?
You shouldn't need to white shade on the RED if I understand the problem correctly. You only get the gradient in 3 CCD cameras, as the light splits through a prism and doesn't align correctly.
Matthew
Sean Adair May 12th, 2007, 09:43 PM The issue is also described as a LENS accuracy problem, but the interaction with the prism makes sense. Personally I think JVC does care, and are developing and producing the best they can. They are a relatively small company, innovative, and working hard to fill a niche in pro cameras. The 200 is the FIRST in its class to offer white shading. Jvc is proud of this rightly. But my rig cost nearly twice as much as the 100 w/ a 16x. Your 100 is in the same price range as "prosumer" style HD camcorders, and far cheaper than other "broadcast" form HD cameras.
There are some compromises associated with this range, but many people just go out and make great work with what they have after learning about it's strengths and weaknesses. Others blame their tools and will always need the next thing. This is not a personal comment to be offended by! I aspire to transcend the tools I work with, although I also face challenges along the way.
I'm sure there will be some early adapters in the RED camp who will be dissatisfied too. I suspect it will transform the high end market, but I'm not as confident about it scaling down for a lower budget. But this is a discussion for somewhere else!
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