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-   -   extreme wide screen with the 100a (https://www.dvinfo.net/forum/panasonic-dvx-dvc-assistant/19520-extreme-wide-screen-100a.html)

Ozan Biron January 9th, 2004 02:45 AM

extreme wide screen with the 100a
 
With the 100a... has anyone tried using a 16:9 lens with squeeze mode on! Does that qive an extreme wide screen look? Does it effect quality? Any point in doing that?

Barry Green January 9th, 2004 09:52 AM

It will give you a 2.35:1 "CinemaScope" aspect ratio...

... that can't be played properly on any television.

If you're going to make something like a web video with it, you could unsqueeze it and crop it, but web videos are typically highly compressed and will sacrifice whatever resolution gains you were trying to get.

If you wanted to make a widescreen film print, it might have applicability, but other than that it's a fairly pointless thing to do.

A better choice in almost all circumstances would be to shoot with the 16:9 lens and "letterbox" mode -- that way you'll still get a 2.35:1 aspect ratio, but at least it would display properly on 16:9 televisions or from an anamorphically-encoded DVD.

Frank Gapinski January 11th, 2004 03:13 PM

2.35:1 "CinemaScope" aspect ratio
 
A good example of this technique can be found here:

http://homepage.mac.com/shailevy/camera/presentderbesuch.html

Ozan Biron January 11th, 2004 03:53 PM

The dimensions to that above video is 600x255! How do you calculate the dimensions for a 2.35:1 "CinemaScope" aspect ratio for web streaming video downloads???

For example videos plays in of dimensions 320x240, 640x480, 720x480 is 4:3 ratio. What will the dimensions be for a 2.35:1 ratio?

Kenn Christenson January 12th, 2004 11:37 AM

2.35:1 is probably one of the easiest aspect ratios to calculate. Just take the height you want the image to be, then multiply that by 2.35 to get the width. Say you want your video to be 240 pixels high, just multiply 240 by 2.35 which will give you a width of 564 pixels. If you need to work backward because you want all the image to be seen on a standard 4:3 monitor, start by dividing the NTSC D1/DV pixel width (720) by 2.35 which will give you 306.383. You will then need to divide 306.383 by 1.125 to adjust for the non-square pixels. The result will be 272.3404, rounded down to 272 pixels high. So a 2:35 letterboxed DV image will be 720x272.

Ozan Biron January 12th, 2004 04:51 PM

What about for a 16:9 ratio. Is it the same way to calculate? Take the height you want the image to be, then multiply that by 1.78 to get the width?

Kenn Christenson January 12th, 2004 05:50 PM

That's right! And, if you only know the width of the image, you'd divide the width by 1:78 to get the height.

Ozan Biron January 12th, 2004 09:08 PM

"You will then need to divide 306.383 by 1.125 to adjust for the non-square pixels."

non-square pixels? wa? Do i also have to do the same for the 16:9 ratio? What will the demensions be for a 16:9 image to be on a 4:3 monitor? 720x404?

Kenn Christenson January 13th, 2004 10:04 AM

720x480 video doesn't use square pixels, hence the more rectangular shape when viewing the video in an application like After Effects. If you're calculating an aspect ratio that will be used in a NTSC digital video format, you'll have to take into account the effect of non-square pixels. So a 16:9 image in non-square pixels would actually be closer to 720x360 (dividing 404 by 1.125.)

Ozan Biron January 14th, 2004 06:56 PM

Im still a rookie with this 2.35:1 ratio stuff! So i just want to make sure...

If i technically filmed with my anamorphic lens and had the letter-box mode on... I could then capture, import my video into after effects, open a 720x480 composition window, set one ruler to (104) at the top and another to (376) at the bottom! Because 480 - 272 = 208 / 2 = 104. Minusing 104 from the top and 104 bottom gives me my "CinemaScope" quide lines. I would then scale the video hight down to 73% to fit in between the rulers!

Is this Correct?!?

Kenn Christenson January 15th, 2004 11:42 AM

It's actually easier than that. Assuming you have the in-camera 16:9 mode selected (resulting in a full frame anamorphic image) and you are using a 16:9 anamorphic adapter. Just divide the height of the 2.35:1 letterboxed frame (272) by the standard height of the frame (480) this will yield the percentage you will need to scale your image in After Effects (.566667, rounded up to .57 or 57%.)

Ozan Biron January 15th, 2004 11:56 AM

instead of "in-camera 16:9 mode selected" im using the "letter-box mode with the 16:9 lens. Doesnt that give the same effect has 2.35:1! So instead of 57% wont it be 73% cause there black bars already recorded....

Kenn Christenson January 15th, 2004 04:40 PM

If your image is already letterboxed in the 16:9 aspect ratio then, essentially, you'll have to apply another 16:9 vertical squeeze to your footage. You calculate the amount of squeeze (scale) by dividing the height of a letterboxed 16:9 frame (360) by the entire frame's height (480) giving you .75. So you'll need to scale your image down to 75% of its original height.

Jon Fordham January 17th, 2004 01:10 PM

For 4/3 television display, calculating the width as 720 is fine. But keep in mind that when calculating the width for any other application, the anamorphic lens is actually giving you a wider aspect ratio while maintaing the 480 vertical height.


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