How To Apply Custom Aspect Ratios In DaVinci Resolve

Custom Aspect Ratios in DaVinci Resolve

Have you ever had a client drop the line, “we shot this for 2:35” in a color correction session? It’s something I come across almost everyday when grading. What does the  the term ‘2.35’ or ‘1.85’ mean? And once we know what it means, how do we use it to create the final image size the client wants? 

What is  the number ‘2.35’?

Hight Definition video has several different frame sizes. The most popular: 1920×1080. That number is commonly reduced to a ratio of 16:9 or 16 pixels of width for every 9 pixels of height… making HD video a long rectangle.

If you divide 1920 by 1080 (or 16 by 9)? That reduces the ratio down to a single number: 1.77 (it actually goes out many more decimal places, but 1.77 is a ‘good enough’ truncation). So a client who shoots a project to fully fill the HD screen would say, “we shot this for 1.77”. They could also say, “we shot this for 16:9”. What about a shooting aspect ratio of 2.35?

Now lets figure out the pixel dimensions for 1920 HD with an aspect ration of 2.35

We’re starting with two numbers: HD Video with a width of 1920 pixels and the aspect ratio reduced down to 2.35. We need to figure out: How many pixels tall is our image? Let’s turn this into a simple equation:

1920 * X = 2.35

where X=Height(in pixels)

Some more basic High School math has us swapping X with 2.35 and ending up with:

1920 / 2.35 (or any aspect ration reduced down) = X

Pulling up a calculator: 1920 / 2.35 = 817 pixels tall.

If standard HD is 1920 x 1080, then our client who shot 1920 but wants an Aspect Ration of 2.35? They shot assuming to the dimensions of 1920 x 817. This is less tall than our HD televisions, forcing us to crop the top and bottom of the image to match the shooting style of our client.

How do we crop an entire timeline in DaVinci Resolve to custom aspect ratios?

That’s what you’ll learn in this Insight. Using this very basic math, a client can walk in quoting pixel dimension, Aspect Ratios or the reduced Aspect Ratio and you’ll learn how to precisely set that up in DaVinci Resolve.

In truth, Resolve has some quick presets you can apply for common crop sizes. But using the technique I’m showing you here, you can now apply your own custom crops to any crazy custom aspect ratios a client hands you.

I’ve listed the numbers below the video for the ratios I’ve used so you can have them to add to your grading toolbox!

– Dan

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