Resolution for Aspect Ratio(s)

[Jeremy Garchow]

Take whatever 4k width your using, and divide it by the ratio

If you’re using 3840 and need 1.85:1 then take 3840 and divide by 1.85.

Alternatively, you can take a pixel height and multiply by 1.85.

It’s easiest to take width as that will fit into a standard pixel count (with letterbox). If you used height, you run out of width in standard frame sizes.

[Thomas Frank]

Thanks Jeremy

I will give it a try….

Don’t understand what you mean with…

[Jeremy Garchow] “It’s easiest to take width as that will fit into a standard pixel count (with letterbox). If you used height, you run out of width in standard frame sizes.”

[Thomas Frank]

So I tried the method deciding the pixels through the aspect ratio.

4096 / 1,90 but I get 2155 which the pixels size actual 4096 X 2160 is for 1.90:1???

[Jeremy Garchow]

[Thomas Frank] “Don’t understand what you mean with…

[Jeremy Garchow] “It’s easiest to take width as that will fit into a standard pixel count (with letterbox). If you used height, you run out of width in standard frame sizes.””

If you went with full height, you’d have to “squeeze” the remains pixels in to the frame (think of pushing the left and right width together and smushing them in to the frame to fit.

If you are using 4096×2160 as the 4k standard, then if you use 2160 as the height, and need a 1.9 aspect ratio, you’d come up with a with of (2160*1.9) 4104 pixels. You have two choices, you can either crop off the remaining pixel width (4104-4096 = 8, which in this case isn’t a big deal) or you squeeze the 8 pixels in to a 4096 frame size.

But, if you use the width as the boundary, then you simply end up with a letterbox. 4096/1.9 = 2156, so your frame size would be 4096×2156.

What are you trying to do, exactly?

[Jeremy Garchow]

[Thomas Frank] “So I tried the method deciding the pixels through the aspect ratio.

4096 / 1,90 but I get 2155 which the pixels size actual 4096 X 2160 is for 1.90:1???”

That’s right. This is, of course, calculating for square pixels. It does not take in to account any anamorphic squeeze.

What is your source material?

[Thomas Frank]

I’am trying to make aspect ratio borders in Photoshop in a 4096 x 2160 resolution.
Also would need one for a 3840 by 2160 resolution.

[Jeremy Garchow]

Then take 4096 and divide by the aspect ratio, and that gives you the height.

4096/1.85 = 2214, frame size – 4096 x 2214

4096/2.35 = 1743, frame size = 4096 x 1753

etc…

[Gary Adcock]

[Jeremy Garchow] “Then take 4096 and divide by the aspect ratio, and that gives you the height.”

It does not quite work that way as the aspect ratios were devised for Film standards and not digital .

A more accurate chart is a https://www.digital-intermediate.co.uk/resolution/resolutionaspect.htm

Currently the best reference book available by ASC member Dave Stump
https://www.amazon.com/Digital-Cinematography-Fundamentals-Techniques-Workflows/dp/0240817915

gary adcock
Studio37

Post and Production Workflow Consultant
Production and Post Stereographer
Chicago, IL

Follow my blog at https://www.garyadcock.com

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[Jeremy Garchow]

[gary adcock] “It does not quite work that way as the aspect ratios were devised for Film standards and not digital .”

Sure, but it’s really close, especially for photoshop guides and square pixels.

[Thomas Frank]

Thanks Jeremy, but when do I know where to add extra pixels and not?