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Old October 7th, 2003, 09:39 PM   #1
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Wide mode of GS100

Soem time ago I was asked on another Forum to conduct a Wide mode resolution test on my GS100 to check its real Wide mode capabilities. Today I did it , shooting short clips in 4x3 and Wide mode (as well Cinema Pro). However, once downloading them and putting through Vegas, the wide frames are letterboxed in preview pan with apparent lesser vertical resolution then the same pattern shoot in 4x3. So far I couldn't see how the cam produce the reproted 854x480 footage, perhaps the only solution would be pbserving it on a real wide screen TV ?

Are there chances anybody knows how to force Vegas preview to display full screen 16x9 instead of letterboxing one on 4x3 pan ?

I have the frame grabs available for anyone interested (tured to be small 45-60 kB JPEGs).

Regards, Alex
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Old October 7th, 2003, 11:44 PM   #2
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Alex, would you please post the grabs on the GS100 Yahoo groups file area. That would be the best thing to do so people can see for themselves.
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Old October 8th, 2003, 05:35 AM   #3
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Just did it, thanks for the advise.

Alex
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Old October 8th, 2003, 07:30 AM   #4
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Alex, I'll reprint something Sam wrote on that tread:
http://www.dvinfo.net/conf/showthrea...e&pagenumber=2

****************************
DV format allows maximum of 720X480(NTSC) to be stored in to mini dv tape(Limitation for dv format). If its 4:3 it stores without any changes directly to 720X480. If its 16:9 then it squeezes the extra wide information to fit inside the 720X480

Its up to the TV to display correctly either 4:3 or 16:9 from that 720X480 pixel information. If the TV want to display as 16:9 then it unsqueezes the already squeezed info(packed inside the 720X480) and show as pictures with out any distortion.i.e convert the 720X480 to 856X480 and display in the 16:9 format.


There is no 720X460 business in these formats. This 720X460 is a middle step to go to 720X480 in GS100k's 16:9(i.e 1.04 digital magnification)
*******************************

Everything is quite correct and I only want to add that link:
http://babelfish.altavista.com/babel...k/ki_wide.html

As even the texts are gifs no translation but the pics are speaking for themselves.

So the actual CCD area in wide mode for GS100 is 934x576 vs. 876x540 for MX5000. This pixel information is reduced to 720x460 and 720x360 accordingly. Why the vertical and horizontal ratios are different I can't explain myself.

This intermediate resolutions are upsampled to fit the DV standard.

The DV format is 720x480 no matter wide or 4:3 (pixel aspect ratio changes from rectangular for wide to square for standard - this is covered in many places at Nonlinear Editing on PC for example). I admit this is also not very clear to me.

Cinema mode is normal 4:3 with black stripes from up and down for display on standard TV. Some newer wide TVs can eventually disgard this banners and show on full screen but the the resolution would drop even more.
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Old October 8th, 2003, 07:54 AM   #5
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OK, but what bothered me is theat the apparent vertical resolution in wide mode appearing in the grabs is considerably reduced (less square bricks area is appearing vertically).

I still have troubles to understand all that with wide format, how it should be treated...neither I'm abale to tailor it correctly in video editor (Vegas, for instance)

I guess the best way to check the issue would be locating some true wide screen TV that would interpret it correctly and check the apeparence on it.
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Old October 8th, 2003, 12:17 PM   #6
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Well as I personally got interested to delve deeper I captured some video and tried to answer all our questions.

As I don't have much experience with NLE I was also wondering at first but software is self-answering thing these days. Just check the Help for anything you do not understand - Vegas has very good help.

So I made 2 variants of my grabs using different project starting settings (or Properties to be more precise). I exported the grabs directly form the Preview (set at full preview to get full resolution grab). File sizes are 80-120 KB.

I posted 6 grabs and a text file with my low knowledge attempt to answer for the people who know even less.

Here it is:
http://groups.yahoo.com/group/NVGS100K/files/Pixel%20aspect%20ratio%20effect/


P.S. I'm just afraid that you should be Yahoo member to be able to access the File area of yahoo groups.
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Old October 8th, 2003, 12:29 PM   #7
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Well, just checked your stuff there (I'm a member of GS100 Group).
Also, just figured NTSC Wide setup for a project in Vegas.

It seems the image in Wide doesn't add any additional video information in the frame, but rather just taking a regular 4x3 angle of view and multiply each pixel by 1.21 as was explained - resulting into apparently wider image but the same resolution is just stretched to the wider view and vertical resolution is reduced.

This is sad but soudsnas a fact.
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Old October 8th, 2003, 07:50 PM   #8
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To be more precise - the vertical angle of view is reduced. (Check the resolution downloading to your photo editor and checking the image size properties).

The horizontal angle is just slightly wider than normal 4:3.

And to repeat again - the camera uses larger CCD area wich produce 460 pixels vertical resolution wich is not the best as it has to be upsampled to 480.

The new Mega Pixel video cams are not doing such upsampling so the resolution is clearly higher. They also use larger CCD area for the first hand capture so the horizontal angle is wider too as I read.

Note:
When taking the shots my actual frame was exactly on the outer edge of the painting frame. It seems the cam shows the safe area directly on it's LCD/viewfinder. In Vegas I could see that the 10% safe area is slightly inside of my intended shot. The whole information though is what you see so it's not so easy to say how wider is the wide mode compared to standard.

In this regard Alex on TV screen you get even lower real resolution as about 8 % of the frame area is not displayed on playback. You will see the full shooting area/frame only on underscan professional monitors. But it's not what you have in your living room usually.

To conclude - take it easy - there is never perfect solution.
To get best out of GS100 I would use standard 4:3.

Still the results for wide are decent and if you have wide TV it's OK to shoot in that mode too. You'll fill up the entire screen so it's worth it.
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Old October 9th, 2003, 12:20 AM   #9
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The better your 16:9 TV is, the more you'd appreciate the quality of the GS100K wide modes.

I've seen the GS100K wide mode on a very good 32 inch super fine pitch 16:9 Wega TV (which is considered as HD-ready outside Japan). I'm sure Pany used their equivalent Pany TVs in evaluating their product. The decrease in clarity compared to 4:3 is apparent, but the quality of the image per se is better than decent IMO.
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Old October 9th, 2003, 12:47 AM   #10
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Yeah, Allan, I with having 16x9-capable TV to enjoy the ability of the cam. I already asked in a few big shops about avaibalility of 16x9 TVs , no one had such in stock and even had no iidea whether they would get a few in some foreseen future. The reason is that the wide screen TVs are considered HDTV and this is not adopted at all in my country (perhaps will pass another decade...). They may show up rarely in some shops but the rpices are erally extraordinary.
So did you see considerable resolution reduction once watching in wide mode of capable TV comparative to regular 4x3 ?
i.e. the cam just zooming in in 16x9 format and no additional visual information added (comparative to regular 4x3) ?

What did you mean by "image per se is better than decent IMO." what is se ?
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Old October 9th, 2003, 01:06 AM   #11
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Aga, Bogdan, yuo're confirming my thoughts. it will indeed fill-in entire 16x9 screen, but with 4x3 -like picture zoomed in and resized to fit 16x9 aspect ratio (i.e.
reducing considerably vertical resolution).
What what is the great deal of their larger area CCD as shown on Jap site ?

What I also do not understand is that having even more pixel-packed CCD (in 1xCCD cams, for instance) and willing to produce a real 16x9 resolution by actual pixels, the cam has to squiz that into standard DV format (720x480) compressing it over regular DV copmression just for taht task, and then, 16x9-capable TVs have to uncompress that 16x9 -> 720x480 compression in order to get back the original 16x9 ??

According to Jap site the GS100 still has enough horizontal pixels to produce a real 16x9 bearing in mind natural 480 vertical pixels.
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Old October 9th, 2003, 05:59 PM   #12
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Alex,

Lets put the things this way:

Think that at wide mode the viewing angle is changed to moderate (from the original 42 mm lens to lets say 50mm).

In such case all you have to do is to go a bit further away from your object to achieve same vertical angle of view. This will lead to much wider horizontal angle of view - so what you say is not correct.

Other thing - if you compare side by side 29 inch Standard TV to a 32 inch wide TV you'll see that verticaly the Std TV is larger but as area the wide TV is larger. In fact 28 inch wide for me is closer to 21 inch standard.


Third - the things you observe with GS100's wide mode are true also for any other cam - GL2, TRV950, etc. I haven't seen the new Mega Pixel cams but that's the facts.
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Old October 9th, 2003, 06:22 PM   #13
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Yeah, apparently I begun to unedstand what is going one.
BTW, just discovered the TV standard (so called D1) defines standard aspect ration of 4:3 (as TV pixels) and active image window of 720x480. However, there is no well defined restriction to window size of 16x9 ! So in fact we can take any number of pixels per area with 16x9 aspect ratio (say, 160x90 pixels) and it will cover entire widescreen nicely !

This is the way DV cams work i Wide format beign restricted to 720x480 window to comply D1.
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