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-   -   GL2 / XM2 Frame mode (https://www.dvinfo.net/forum/canon-gl-series-dv-camcorders/3415-gl2-xm2-frame-mode.html)

Frank Granovski January 21st, 2004 06:21 AM

David, Sony uses Canon's OIS technology.

Some types of OIS actually degrade the image a bit. This is so with some of the Pana's OIS, like with the MX300/0. In fact, Pana states this. As far as I know, Canon's and Sony's does not degrade the footage.

Jerry Norman February 17th, 2004 05:28 AM

Mike, regarding your comment that GL2 does widesscreen the right way - does the GL2 create a full 720 x 480 image with and without the anamorphic lense? If so, why is the anamorphic lense a better solution?

<<<-- Originally posted by Mike Ostracky : When shooting in frame mode you can control everything, and that`s the beauty of film making - manual, the only way to go ;)

Anamorphic on GL2 (XM2) does widescreen "the right way" - it stretches it, it (luckily !) doesn`t letterbox the image - but still, the anamorphic lens is the best way to go.

On great majority of modern TV sets you have 16:9 button on remote to "unstretch" the picture - thus making it appear as it should, widescreen and without any resolution lost (which is noticable when letterboxing).

Hope that helps. -->>>

Mike Ostracky February 17th, 2004 05:42 AM

Hey Jerry,

Yes, GL2 (XM2) creates full resolution anamorphic widescreen image - but still, you loose some small percentage of resolution (the same you would loose by letterboxing) because that area is really cropped and whole image is than stretched.

The interesting part is that GL2`s widescreen produces suprisingly good looking images, far better than letterboxing or anything you could do in post - there was an article about it (with images), but I can`t remember the URL.

There is an interesting, pretty cheap way of doing great looking widescreen without anamorphic adapter (which is expensive) - wide angle adapter (WD-58h) + in camera widescreen mode = excellent image.

Jeff Patnaude February 17th, 2004 08:51 AM

My meager two cents...
what they said- but if you want to add a "blurred" effect, why not shoot it and add the effect in post? I believe a "motion blur" filter will give you the desired effect. Not sure what you are editing with however.

good luck,

Jeff Patnaude

Bill Ravens February 17th, 2004 09:01 AM

motion blur isn't really what you want to use....use gaussian blur, add a little glow and film grain, too.

David Yorio February 21st, 2004 08:26 PM

De-interlace VS. Frame Mode
 
Is there a difference between De-interlacing in post production and filming in the Frame Mode?

It seems to me that de-interlacing on Final Cut Pro would achieve the same effect as filming in the Frame Mode on the GL2.

Any thoughts or experiences with this?

Thanks,
Dave

Ken Tanaka February 21st, 2004 11:30 PM

Yes, actually, there is a difference. Frame mode on Canon cameras such as the GL2 is, for most practical purposes, progressive mode shooting. That is, both fields are simultaneously produced from the scene in each frame of the video.

Software deinterlacing is a synthetic process that generates one field from the contents of the other in each frame.

This is not to say that all software deinterlacing is necessarily inferior to frame mode shooting from an aesthetic perspective. But it is never truly the same as progressive scene capture.

If you explore software deinterlacing more deeply you will soon discover that it comes in two varieties. The simplest (and least desirable) deinterlacing algorithms are those that simply copy one field directly to the other verbatim. The more sophisticated deinterlacers use proprietary algorithms to "intelligently" generate one field from the other field and from the contents of the previous and the next frames.

This is an easy matter to explore for yourself by experimenting with your GL2 and your NLE.

Have fun!

Graeme Nattress February 22nd, 2004 07:43 AM

I thought that the pixel shift technique that the Canon uses is not "progressive", but so sort of in-camera de-interlace.

Either way, Ken's right that if you shoot true progressive, you're not going to get better in post. However, there are many ways to de-interlace, and adaptive, or smart deinterlacers like which are used in my Film Effects work extrememely well - Iv'e got some example pictures of 60i v 24p on my web site at:

http://www.nattress.com/BirdBrains/b...nsPictures.htm

Which shows how good software de-interlacing can be! It's certainly worth experimenting with the Canon's frame mode v software de-interlacing though.

Graeme

Bob Benkosky February 26th, 2004 03:09 PM

I've found that shooting without Frame Mode and rendering to Vegas's Progressive field order and 24fps turns out overall more film-like than frame mode alone. I've done many tests too.

I also tried Magic Bullet vs Vegas and I liked Vegas better.

I mean, let's say you edit the project in Vegas.....putting in everything you're going to do including effects/color corrections and stuff, then dump it back to dv format, or uncompessed, which is going to be a very large file, then you convert it to MB.

After that.... You pretty much have to output it uncompressed because in MB the dv/dvpro codec looked horrid for some reason. I figured it shouldn't be, like when you dump it from vegas to dv format, but it's not the same for some reason. You have to use MB in uncompressed, which sucks. Then it has to go back into Vegas so you can make a DVD NTSC/PAL movie out of that.

So I did some tests on both ways and using Vegas with 60fps to 24fps with effects looked great. Granted the mpeg2 encoder Vegas uses might not be THE BEST....you could always go with Procoder on it's highest setting, which will take forever, but should look the best you can get.

You might not notice on normal TV's, but in HDTV the mpeg2 encoder will show it's weaknesses.

That's my 2 cents.

Rob Lohman February 27th, 2004 03:08 AM

Graeme: that's basically correct. But it isn't a true de-interlace
either. The timings are changed so that the full signal is recorded
at the same time basically. It doesn't use the full CCD array for
everytime since it isn't a progressive CCD array. This is where
the pixelshift technology comes into play. The downside is that
you loose (color) resolution but it basically is captured at one
point in time instead of two.

Robert Boudreau February 27th, 2004 10:47 PM

Progressive vs Frame Mode vs Progressive Shutter
 
Perhaps Rob can explain a little more about how the Frame mode works. I currently have an original Canon Optura which films in progressive and I use this to catch fleeting moments, capturing 640 x 480 stills in action shots.

Would the GL2 in frame mode give better resolution than my old optura in progressive mode? I realize GL2 has better low light sensitivity, but assume there is plenty of light. What is the trade off between frame mode and progressive scan?

Sony uses progressive shutter. Is this the same as Canon's frame mode?

How can you capture an entire 640 x480 frame at one point in time using an interlace sensor?

Robert Boudreau February 29th, 2004 09:45 AM

Progressive vs Frame Mode vs Progressive Shutter
 
I did some experiments comparing my Optura's progressive scan mode to deinterlaced interlace mode, using several different deinterlacers (Adobe Photoshop, iMovie, Image DV) and the progressive scan mode was always better.

I did find a thread that explained how frame mode in the GL2 has identical resolution to progressive scan using an interlace scanner(by scanning the green CCD of one field at the same point in time as the red and blue CCD scanning the second field). The picture resolution is maintained, but you lose some color resolution compared to true progressive scan.

I looks like I will work towards buying a GL2, unless a GL3 comes out soon.

I don't know why people complain about the "uselessness" of the two megapixel photo mode compared to just carying a separate digital camera. To my knowledge there are no digital camera offering a 20 X optical zoom

Does anyone know how Sony's progressive shutter works?

Jim Cottringer February 29th, 2004 01:24 PM

Article on progressive scan
 
For an excellent article on the various flavours of progressive scan you can check out Steve Mullen's article at:

http://videosystems.com/ar/video_progressive_need_know/

Robert Boudreau March 1st, 2004 02:42 PM

Yikes! The paper by Steve Mullen is very good, but if I understand the paper correctly, there are some significant compromises by using frame mode compared to progressive scan.

The good news is that 1) frame mode collects twice as much light (6 dB more sensitive) so it will have better low light sensitivity. and 2) there is no interlace artifacts because both fields are collected at the same time. The bad news is that the vertical resolution is deteriorated from 480 effective scan lines down to 320 because of summations. Partial RGB Elements from 3 rows are summed together to give the information of a single row, elements being delayed one row time or two row times so they all are from the same point in time.

According to the paper the 320 vertical resolution of frame mode is slightly worse than the effective vertical resolution of 360 for interlace video. Frame mode, though, has no loss of horizontal resolution because no deinterlacing is needed, but interlace video would suffer this loss. The deinterlacer then can recover it.

I guess the bottom line is progressive scan is best as long as you are not in a low light situation. After that, frame mode would probably be next best in quality if significant movement is present; otherwise deinterlaced interlaced video would be next best.

I hope Canon puts progressive scan back in their high end cameras.

Robert Boudreau March 1st, 2004 03:20 PM

I probably should have also mentioned that the reason interlace video has a vertical resolution of 360 instead of 480 is because, according to the article, interlace video also does summation of two rows to make one row in an effort to boost sensitivity by 6 dB. Frame mode uses parts of 3 rows, giving you the 320. This summation stuff is therefore used by both interlace and frame mode methods.


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