Small, and I mean SMALL file

[Terepasztal Lovagja]

Hi guys,
Is tere a way to export a small transparent lower third-type 1920x1080 video from After Effects CC (2019) under 2-3 Mbytes of file size? If I use the CS6 version, open the same AEP file and export to FLV, the site is 1.177.276 byte. Of course that's an FLV file, what is not supported nowadays. Great. Now same AEP file, export to QuickTime. The smallest possible size is 23 MByte.
The reason why I am doing this: in my 20-30 min videos there are a LOT of lower thirds and titles and other AfterEffects goodies. These videos are 2-3 gigs after exporting from Premiere Pro CS6. With these mammoth quicktime files, the filesize is waaaaaaay larger.
Thank you very much.

[Martin_Ritter]

What's the deal with filesize?

You can only export the lower third part, not the whole HD image. This requires prober placing in PR, or whereever it is inserted. 

If you don't mind quality, just export it as H264 (with a seperate alpha mask, since H264 has no alpha). You can shrink file size a lot, but don't expect a crystal clear image or accurate colors. H264 is only usable for final internet delivery. If there is any processing step like color correction, this is not an professional option at all.

However, if you want quality, there is no way to shrink the file size. Working with professional codecs like DNxHD or ProRes usual end up in very large files. The image information has to go somewhere.You can try to zip the files after export in case you have to transfer them.

*Martin

[Terepasztal Lovagja]

The old FLV quality would be fine. That contained just enough image information. ProRes 4444 is the best, at least it produces the smallest filesize. This separate alpha mask thing sounds interesting, I'll dig up something. Never used this method before.

[Dave_LaRonde]

Get more storage.  It's cheap.

[Rick Gerard]

If you want consumer files (h.264 MPEG) you'll have to export two of them. One rendering alpha only so you end up with a black and white file you can use as a track matte, and the other rendering the video. MPEG does not support 4 channels, only 8 bit RGB. You need a professional format that supports at least RGBA, has all of the information in every frame instead of making up at least 1/3 of the frames by predicting how the image is changing using the IBP frame sequence. Like Dave said. Storage is cheap, buy a drive.