More and more 4K cameras are appearing on the market at affordable prices, and with them come a number of intriguing compositional possibilities, for cropping images without any loss in quality (reframing and panning and zooming in post), or presenting them in different aspect ratios. Even shooting in boring old 1080p 16:9 gives you some “scope” (pun intended!) for changing the composition in post, by cropping to a wider/ narrower aspect ratio in post, such as 2.35:1.
Given that Vimeo and other video services have native support for a number of different aspect ratios rather than just vanilla 16:9, wouldn’t it be good if you could output your videos in native 2.35:1, rather than having them in 16:9 with black bars at the top and bottom?
OK, so perhaps this seems like a very minor thing to achieve. If the user hits the fullscreen playback button, then it isn’t going to make a difference whether the black bars are part of the video stream or not. But for playback when the video is embedded as part of a site, doesn’t this:
Look better than this?:
I was looking for a way to do this, but all the tutorials I could find online used Compressor. Now, Compressor is a very fine onlining suite, and it’s only $50, but if your onlining needs are not more involved than uploading to Vimeo, then that is $50 that you could spend elsewhere.
OK, without further ado. There are 3 steps here.
- Apply the Letterbox effect to each clip in the timeline. In theory, this step isn’t really necessary. It just adds the black bars at the top and bottom of the image that we are going to crop away in the next 2 steps anyway. So why do it? Firstly, because with the “offset” control it adds an easy, keyframe-able way to pan vertically within the image (without overshooting the edge of the cropped area). Secondly, if you do ever have to output to a format that does not have native support for 2.35:1 (such as a DVD), then you can simply switch off steps 2 and 3 and have consistent-looking video regardless of what aspect ratios are supported by the delivery format.
Change the aspect ratio of the project. Bring up the project properties by hitting Command-J, or selecting the project and clicking the info tab in the inspector. Hit Modify Settings. Under Video Properties, Format, select Custom. OK, now some maths is necessary. Maintaining a horizontal width of 1920, an aspect ration of 2.35:1 would produce a vertical height of 817.02127659574468. Initially I assumed going for an even 818 might be best, but this leaves a tiny trace of black line at the top and bottom of the image at the end of the process, so 1920 x 817 it is.
However, this alone does not produce the desired output, as the 16:9 aspect ratio video, with the black bars, is resized so that it fits in the new narrower frame in its entirety, producing this effect:
I wonder whether there is some setting somewhere to say “fit to one dimension”, rather than defaulting to having the entire image visible? In the absence of this setting, we will have to…
Crop the entire project. Right, time to crop away the black bars we created in step 1 in order to have a truly 2.35:1 video. As this has to be applied uniformly across the timeline, I apply an RT Adjustment Layer to the entire time line:
Then place the Crop effect inside the adjustment layer. Make sure “type” is set to crop. trim just replicates the black bars of the Letterbox effect, rather than actually resizing the image.
OK, time for some more maths. How much do we need to crop from the top and bottom of the image? It turns out the answer is 100 pixels from each side. If you’re not bothered about how I arrived at this figure then you can skip the rest of this paragraph. Why 100 pixels? We have a 1080 high image, that we want to crop to 817 pixels high. That’s a difference of 263 pixels, so I initially thought I’d have to lose 131.5 from the top and the bottom. But, this 1080p image is already being compressed into an 817 high video frame, a squeeze factor of 1.322. So those 131.5 pixels are also being squeezed by that factor, which comes out as 99.47.
The finished effect:
If you think my calculations are off, or you know an easier way of doing this, then write a comment below.