Michael,
I want to ask you about the resolution loss you're talking about. You might be right that the CCDs only use 75% of their resolution when in frame mode.

But, Canon says their CCDs are 410,000 pixels. That gives about 640 x 640 resolution of just the CCDs. If you take off 25% of that 640, you get (nor surprisingly) 480, the exact vertical resolution of MiniDV, and the exact resolution of the resulting digital film frames.

Isn't the proper calculation how much frame mode reduces the resolution of the CCD, and not of the MiniDV image? And if I'm right, then reducing the CCD resolution to 640 x 480 is only minimally harmful because it creates images in the exact output resolution. If anything, it's better.

So I guess my question to you is are you certain that in your 75% calculation, that's 75% of the resolution AFTER the CCD images are converted to 480 lines, or before?

It is important to distinguish between pixel count and resolving power.

The SD TV image will always be the same , i.e. 720 x 486 NTSC and 720 x 576 PAL, but the resolving power of the CCDs (i.e. the ability to resolve individual lines) will change depending on the mode etc. Many pro camera data sheets specify that the chips can resolve 800 lines +, but the DV25 standard on tape or in a PC can only resolve a little over 500 lines. So when people talk of losing 100 lines rez that is not the same as losing 100 actual lines from 486 or 576 vertical TV lines. Of course starting with that much greater image resolution at the camera head in the first place certainly pays dividends.

This why I believe the frame mode does not show a straight subjective drop of 25% vertical resolution.

It is important also to bear in mind that many filters like diffusion, Pro-mist etc. will have an effect on resolution, possibly in some instances greater than that produced by frame mode, and yet these filters are regularly used on Digi Beta shoots.

The fact that it makes frames out of the raw pixel shift data helps. But aliasing is increased as soon as you switch to FM. I did extensive tests with the GL2 and it put out a nice image but it couldn't hold up in the uprez process. The GL2 is a very good camera for its price. It's image is sharper then that of the XL1S. But FM and the way it emulates progressive is not the best way. It was explained to me by Canon that a field is captured ( not a video field but raw ccd data ) and the offset pixel shift data mixed in there completes it as a full frame. The look of frame mode still has a film feel and is more pleasing then 60i look. By the way I can't speak for Pal cameras since I'm in ntsc land.

If you really want to see what frame mode does to the quality vs regular. Film a 1956 resolution chart. Set up a 800+ line monitor. Switch between the two modes. That's speaks more the all the typed words I can do.


If you want to see what true Progressive DV looks like. Check out John Beales latest tests. Scroll down to the last few tests. There you will see what 60i looks like vs true Progressive. Even on the DVX100 it's 60i test can't compare when it's switched to 24p mode.

Here is the link:

http://www.bealecorner.com/trv900/cats/cats.html

Michael Pappas

Michael, I don't know the people you know at Canon, but I called Canon tech service and the person (after considerable clicking on his computer and talking to other people there) said " In Progressive Movie Mode/Frame Movie Mode every other frame has 3/4 of the lines of resolution and the next frame has all the lines of resolution which is why it can look choppy." He said I could get the best quality still photo(vs interlace mode) by using Frame Movie Mode and selecting the frame that had all of the lines to print out. I am just repeating what he said and I don't know what this means, but the "every other frame has 3/4 of the lines" does tie in to earlier comments about losing 1/4 of the resolution. The every other frame thing could also possibly tie into other comments about the strobing effect you get when using Frame Movie Mode (if every other frame was slightly different). Does any of that make sense??

"If you really want to see what frame mode does to the quality vs regular. Film a 1956 resolution chart. Set up a 800+ line monitor. Switch between the two modes. That's speaks more the all the typed words I can do."

I too , as I have already mentioned, looked at both modes with high rez broadcast monitors (PAL only). I have 20:20 vision; have never worn glasses; have worked in film and broadcast TV for 20 years and I simply do not see the dramatic drop in quality that you imply when using frame mode as opposed to normal interlaced. Of course there is a drop in quality (and let's be frank we are not comparing XL1s frame mode to Digi Beta progressive) but I do not see a 'subjective' drop of 25%, and as I mentioned filters can have a major impact upon this matter too.

We have to be careful when we use comparative resolution tests because much creative film and video manipulation is by its very nature damaging to resolution yet the end result remains pleasing.

There's another way to tell that frame mode is not nearly as bad as some might think. Just compare it to 16 x 9 mode, where a good part of the image resolution is without a doubt lost. Compare a 16 x 9 mode interlaced video to a 4 x 3 progressive video and you'll see that the 16 x 9 mode has MUCH less resolution than the 4 x 3 frame mode. Probably because the 16 x 9 mode actually takes the 480 line video after processing and cuts it off into 16 x 9, as opposed to using the native CCD pixels, which is what it should.

I'm a novice to this whole thing but i spoke to a couple guys who knew more than me and the best advice they gave me was "trust your eyes". Whatever looks better to you and you like the look of more, go with that.

I was all excited about frame mode when i got my GL2 but after using it on a day of shooting some mountain bike footage and then working with it in premiere, I realized that i prefer
de-interlacing alot more. I think it looks better and I can get very smooth slo-motion when shooting in Normal.

Resolution charts and prints of kittens only tell part of the story. If all I did was shoot resolution charts and posters it would be easy to tell which camera is best. Take a look at how Popular Photography does it's test. Yes, they do all the prerequisite charts. However, subjective user data is also used to determine which image looks best. Similar online reviews are found at http://dpreview.com/ and http://www.steves-digicams.com/default.htm subjective reviewer results are always included.

Resolution charts are fairly outdated as a means of evaluating total performance. Zeiss lenses in the '80's didn't always have the highest resolution. Yet their images were generally regarded as the best. Zeiss took the forefront in championing the use of Modular Transfer Function as a means of evaluating optical performance. Highest resolution doesn't always produce the best image.

Jeff

All this talk but no movies....

I'd like to see the GL2 perform these operations:

Frame mode: of a typical action shot either panning or not
Normal mode: Same shot as above

16:9 Frame mode: of above shot
16:9 Normal mode: for above shot

In full resolution and mpeg2 compression maybe a 3-4 sec clip each....

Does anyone have these already available?

I'll be purchasing a camera in the next month or two and don't have access to and pro-sumer cameras without going 3 hours round trip out of my way to test them.

Any help would be greatly appreciated.

<<<-- Originally posted by Michael Pappas : ....A few weeks ago I took Canons GL2 and filmed a 1956 res testing chart and macbeth color chart. ....

Michael Pappas -->>>


Michael

Do you still have the frame grab of the 1956 chart that you shot? If so can you send it to me at krisp9@yahoo.com

Kind Regards

Jayvid

Here are some pics in frame and normal mode.

http://homepage.mac.com/bhardy3/PhotoAlbum32.html

Just to see, I took some digital photos of the subject with my 2.1 MP Sony camera. They came out kinda fuzzy and lower than normal quality without the flash in the same low light conditions. This says a lot to me about the GL2.

Thanks for the attempt but I'm looking for a comparison of movies in frame and normal mode, not still shots.



<<<-- Originally posted by buddy1065 : Here are some pics in frame and normal mode.

http://homepage.mac.com/bhardy3/PhotoAlbum32.html

Just to see, I took some digital photos of the subject with my 2.1 MP Sony camera. They came out kinda fuzzy and lower than normal quality without the flash in the same low light conditions. This says a lot to me about the GL2. -->>>

I just purchased a CanonZR40 to temporarily take some of playback brunt off my GL2. I am immediately hearing extreme audio dropout when I play back tapes shot on the GL2 in the ZR40. I usually shoot in Frame mode, so I switched to normal and tested with that-the short test I did seemed to be fine. Is there an obvious reason for this I am not aware of?

Hi David. The only thing I can think of is that the ZR doesn't have frame mode and perhaps cannot properly play bayback GL2 progressive footage? Or perhaps the ZR's heads need to be cleaned?

Might be old vs newer tapes. Frame mode relates to how the CCD was read and the DSP applied to the signal off the CCD, not to recording on tape. So frame mode should not effect the ZR-40 playback. The problem you describe is common with LP speed recordings played on another machine. Alternatively it could relate to tape read errors caused by slightly dirty heads, slight differences in tape path allignment between the two machines, or light imperfections in the tape combined the the other two.

Hmm. If it's Dirty heads that's easily remedied. All my tapes are SP so that shouldn't be it and the tapes are all Sony Premium and relatively new. If it is a slight alignment difference this is going to always plague me unless I have one of them aligned, no?

I would try a head-cleaning tape one time, for about 5 or 6 seconds (no more). See if that clears it up.

Cleaned the heads and the problem persists-It's strange it's only with material shot in Frame Mode...

If you can, try a third machine and see if the issue presists.

I'm going to shoot a wedding with my XM2 and I've read that some people use frame mode for this.

I've also read that you have to be carefull with fast moving objects while shooting frame mode ... so, the ceremony shouldn't be a problem, but what about recording dancing people at night?

And is it "safe" to use frame mode in low light conditions? (church, evening shots, ...)

Something else, is it a good idea to white balance everytime you take a new position during the church ceremony? Or is it better to white balance in the beginning of the ceremony and leave it, even after changing position?

Yep, I'm a newbie ;-)

do a search for "Frame Movie mode" or something to that effect. There are lots of post about that subject.

Rob

I would just shoot in regular mode, but perhaps for some special scenes, use frame mode. This will give it that look. You know. Perhaps experiment with this, and other things before you shoot that wedding. I find a low shutter of 1/30th or 1/15th, for indoor dance scenes, will add a nice blurring effect---but use a tripod for this. Another thing you could do is use a soft filter for special close-ups of the bride and groom. There's lots of things you can do. However, it's better to keep things simple, use a tripod, and vary your shooting angles: high pointing down, low pointing up, etc. Shoot small segments, unless you're going to edit in NLE.

One more tip. Try not to fall into the zooming, panning, and tilting traps. Use these sparingly---or for effect for certain type of scenes---like dance scenes.

Good luck with your shoot!

If your intended delivery medium is web video, use frame mode. You'll need to deinterlace anyway if you want to put it on the web, so you might as well do the deinterlacing in real time in-hardware as you shoot.

Yes, it's safe to use frame mode to shoot in any sort of condition that it would be safe to shoot using interlaced mode. All frame mode does is drop the lines from one field and regenerate them back from the other field using interpolation.

Frame mode does not drop one field and then interpolate from the reaminng field. It uses a sort of vertical pixel shift system sampling from both fields taken at the same instant. The net effect is half way between true progressive and single field interpolation, and it provides better resolution than interpolation of a single field.

In any case, try it and the alternatives before using it on a money shoot to be sure the effect is acceptable to you. As with slow shutter, frame mode can produce good and bad effects on motion, depending on what you want to achieve.

One problem with frame mode though is that the slow shutter speeds, the digital effects ones below 1/50th don't work. They only work in normal mode.

Frame mode gives the motion appearance of film. Normal 60fps video looks very real, like you're seeing it with your eye. 30fps frame does jitter a little with fast pans. It should not affect keeping the camera still on fast dancers though. The shot will just look a little less life-like, but many would call that artistic and film-like.

To me, 60fps video looks a little sterile. Motion-wise it looks like I'm standing there. I don't like that for dramatic or artistic productions. For a wedding, I think you'd want the film-like motion.

I shoot dance and theater and I use progressive mode exclusively, mostly with a 1/60 shutter.

Don't be afraid of progressive mode for dance, or anything else for that matter.

"Frame mode does not drop one field and then interpolate from the reaminng field. It uses a sort of vertical pixel shift system sampling from both fields taken at the same instant. The net effect is half way between true progressive and single field interpolation, and it provides better resolution than interpolation of a single field."

Don, thanks for the valuable correction. I'd like to see a more in-depth explanation of this process. For instance, what's the algorithm for it so it might be implemented in software? (This would be useful for matching up footage that wasn't shot with FMM to footage that was....)

My Optura Pi manual states that it has a "progressive mode" with 360,000 effective pixels.

Is this the same as the GL1-GL2 "frame mode" or have I got a true "progressive mode" camera? Whatever it is, I use it exclusively for my shooting.

(BTW: I just read a review of the Pana 24p DVX100 and it stated that the Pana had a "true progressive mode" not a "frame mode with pixel shifting" like the Canon.)

Are there any rumors of upcoming HD Foveon X3 cams?

The Optura Pi has a true progessive scan CCD. Frame Movie mode delivers the same results as progressive scan, but through different means (related to pixel shift). The Panasonic DVX100 has pixel shift as well as progressive scan. Hope this helps,

I got my GL-2 used it a few days, set it on frame mode, and left it there.

I have used it in low light, for bands, music videos, family stuff, and a couple of shorts I'm working on.

My current problem; Now I need another (bigger) hard drive!

my 2 cents,
Mark

I've read quite a few arguments about Frame Movie Mode vs Normal mode on the GL2 and I'm still a bit confused about exactly what the difference is between the two forms once you capture the video to a PC.

I understand how each mode records the video to tape, but I've read that when the video is played back and captured using a DV codec (ie through Vegas Video) that the format of the codec is always interlaced. What I am having trouble understanding is, what does it buy you to use Frame mode if the video you capture is going to end up being interlaced anyway?

I'd appreciate your comments. Thanks in advance.

Frame mode gives you a cool "look." Some people say it's a film type look. Personally, I like shooting in frame/progressive mode for certain things.

As you know, in frame mode the visual informationm in both both fields of the frame were captured at the same instant. rather thatn separated by 1/60 of a sec. In this respect the frame mode image is like progressive scan (except that the resolutionis a bit less).

However, for NTSC video, the analog output and display on a TV is always interlaced. odd number line in one field, even numbered in the other field separated by the same 1/60 of a second. It is the nature of the NTSC signal.

The film look thing is in large part due to how motion is presented. With Frame mode the scene is sampled every 1/30 and in movie mode it is sample every 1/60. The net result is motion looks smoother in movie mode. Think how bad fast pans look on the big screen movie relative to video. The interlace display is part of why TV pans look better.

Don, can you post data on what you know of the algorithm behind Canon's Frame Movie Mode? I'd like to see if I can't implement in in software (as an After Effects plugin, for example).

I think there is a link or article somewhere in the DVInfo.net site.
I don't have it anymore myself.

The only difference between interlaced/normal and progressive/frame
is that the timing between the two 'fields' are different. As Don
also pointed out.

Interlaced in the digital world is just a different way of storing
the information. If you shoot interlaced there will be a small
time difference between the two fields. With progressive this
does not occur (but on the current Canon cameras this will
result in a lower quality) but the frames are still split up into
two different fields (which have been recorded at the exact
same point in time) and stored that way. But that does not
alter the look in any way. The way it is recorded does however.

Hope this explains some!

Rob,

Thanks for the info, it has been helpful. Based on what you've said and what I've read, what I'm wondering is, what's the difference between shooting interlaced and deinterlacing in post, versus shooting in frame mode, then deinterlacing anyway in post?

What I want to know is what is the best method for making a progressive copy of frame mode video through vegas video or adobe premiere? I'm assuming that based on what I've read, it would be to render the video as an avi with field order set to progressive scan. What I'm concerned about is how vegas creates a progressive scan file. I don't know whether it merges the two fields together or if it takes one field and duplicates it.

[EDIT] For some reason I've also had trouble getting vegas video to capture video at full 720x480. The files it creates play as 360x240. [\EDIT]

Right click on the clip or the event and choose properties.

It will probably say something like Attributes 720x480x24, 00:46:16:13 Format DV.

Now right click on the Preview Window and put a check mark on "Display at Project Size". The Preview at the bottom will change to Preview: 720x480x32 29.97p. With the preview window maximized it will Display: 640x480X32 (or 807x480x32 in my case because it is 16:9 widescreen).

If this isn't the case, then I am at a loss to explain it.

Thanks Tom,

I still have my video interlaced but it looks much better in preview mode now.

I also consulted the vv3 manual and it was helpful too. I'm still a little confused about how vv3 treats interlacing when exporting video. I think it may be a more codec specific problem than an NLE one though.

I'm trying to find a way to render a close to lossless 720x480p from a regular DV 720x480i input. I believe that DV is 30fps, so that there must be 60 interlaced frames, so there should be a way to create a near lossless 720x480p output around 30fps...right?

I do not have specific detailed data on the scheme used for Frame mode, just fairly general information. It is essentailly something like a given line in field A = the green lines from that field plus the average of the adjacent red and blue lines in field B. A given line in field B = red and blue lines from field B plus the avarage of the adjacent green lines in field A. All on a pixel basis of course.

The problem with converting interlaced material to progressive
is the (small) time difference inbetween the frames. If the camera
or something in frame was moving you will begin to see feathered
lines. This is hard to remove in post, in fact it is actually impossible
without some loss in quality. But since the Canon's frame mode
is also a loss of quality it does not matter much. The best would
be true progressive scan (which would require a more expensive
CCD block and timing electronics and such).

If you shoot frame mode the WHOLE frame is made at the EXACT
same time, so there is no movement. The Canon's do this buy
coming certain rows and data from several of the CCD chips to
create a full resolution image. Since it is combing some quality
(what you also can call resolution, is lost). But it does this all at
the same time, so there is no time difference between the fields.
Hence no line feathering or de-interlacing worries.

That is the best way I can describe it for now, I hope this all makes
some sense!

Thanks again Rob, that makes a lot of sense now, I hadn't thought about it that way.

Hey, I was thinking of getting the GL2. How does it do with fast action shots in frame mode? I will be using it for shooting short indie martial art movies.

It all depends on how fast you plan on moving (panning/tilting) the camera. When shooting action in frame mode you should use TV and set the shutter speed to 50/60 depending if you use PAL/NTSC. Faster shutter speeds will produce a jerky footage, as will fast pans/tilts of the camera. You can use filters, polarizers, NDs etc to control the exposure.

It can be done but it takes some careful plannign of camera movements for your shots. Especially with a GL2 which is small and easy to move quickly when hand held.

I will be shooting in NTSC here in the U.S.A. I saw a clip of the DVX100 in 24p standard with fast motion and the motion was jettery/jerky, plus the picture did'nt look filmic to me. Heres the link http://www.mycen.com.my/dv/dvx100links.html

But then there is the "Christmas Magic video" found here http://momentsinmotion.com/demo.htm and this vid was amazing. I wonder did they just shot it 24p standard default or they did some stuff with the camera and post production.

I'm sorta choosing between the two (GL2 and the DVX100). If I could get the same picture quality as the "Christmas magic video" with out post production I will get this camera right away but the first link I posted above shows otherwise.

I always make a point of shooting in interlaced when shooting fast action, unless I want to do it as an effect here and there throughout my footage.

The GL2 performs wonderfully at 30fps. It's really just a built-in de-interlacer. In my opinion, frame mode shoots action shots much better than interlaced, because there's almost no blur.

That was a cool christmas video, I did a similar one with my kids last christmas. Mine was a 30 min production though.

I've used the frame mode almost exclusively for several years, and have rarely seen any issues with photographing moving subjects. The frame mode's 30fps is slightly smoother than film's 24p, and somewhat less smooth that 60i footage. By using good camera handling techniques...ie avoid fast pans and lens axis rotations (hand-held camera jiggle), you really shouldn't have a problem. Keeping the shutter speed at 1/60 is also recommended.

I've posted this clip here before, but if you haven't seen it, heres a few minutes of action shot on a gl1 in frame mode.

http://homepage.mac.com/barrygoyette/iMovieTheater4.html

Barry

I don't know why a lot of people likes the Frame mode. Perhaps it is because they use an NSTC cam at 30p (I haven't tested 30p). I have a PAL XM2 and I always prefer 50i than 25p.

If I want a film look, I deinterlace then add a little motion Blur. This the best solution that I've found after many tests.

I was testing out frame mode on the Canon xm-2 and wanted to see how it looked. I tested a 1 minute shot and played back the tape on in the camera. The shot looked pretty much the same to me when viewing the clip from the camera lcd screen. I guess I'm doing something wrong. Any ideas?
I did the search but came up with nothing.

BTW, The zoom control of this camera is truely amazing. I'm talking about the slowest zoom of all. Just like how the big film makers do in major movies. I'm really impressed. Big plu for canon.
I'm still testing this baby and finding out some nice features. Yep, this is my first camera. So far so good.