Letterbox only some clips

Is there anyone good way to do this? I've searched high and low but haven't found a decent solution.

I have a timeline where I would like to crop to 2.35 on about half the clips. Output Sizing blanking crops all frames as you would expect, there is no blanking option in Input Sizing and Edit Sizing blanking doesn't really cut it as it applies blanking before resizing so if I want to rack a clip I have to offset the blanking accordingly. If it applied blanking after sizing then it would be some sort of solution although I would have to manually set the same blanking settings on each clip.

Ideally there needs to be Input Sizing blanking with an option for project wide blanking and a further option for any single clip to ignore this and use it's own blanking settings.

I did a job a few weeks back with 3 or 4 different letterbox settings, the easiest method I could think of was to import different tiffs with black bars top and bottom but this gives a hit on playback.

Yeah, I would suggest your last option and simply use a tiff mask with an alpha with the different letterboxes that you want and just keep your main timeline at 16x9 (pre-masking).

I did it that way for a project and it worked fine, playback hit was minor.

You could use marks on the Timeline Track to mark where you want the letterbox (Output Blanking) to turn on or off.

This is how I did it. A work-around:

1. Take a screenshot of any black strip. Anywhere from internet. Make your own in MS Paint. Download a jpg etc. Just get any picture with black file.

2. Add it onto the timeline like a video. Click it.

3. Open Inspector.

4. Adjust zoom, size, position, such that the strip goes on the top and looks like a letterbox.

5. Do the same for the lower part of letterbox.

6. Voila! You can now drag the length of this jpg file as long as required, over the clips you need to. Add more if required later on further clips.

Kind regards,