Photoshop 22.3.1/After Effects .TIFF file ALPHA channel support changed or broken?

[Martell]

Animator/Motion Instructor here. Windows 10 edu machines. Photoshop 22.3.1. After Effects 18.1.0(build38).

Animating on paper, then scanning to a TIF. Cleanup, matte, and color in PS, comp in AE. Old process, but works well.

TIFF file workflow seems to have broken with an update. .TIFF file alpha channels are no longer saving and can't be applied in post. I have used/taught this method for years and now it's not working. 

Currently, If I:

1. Open .tif scanned image
2. Create selection and make alpha channel (in CHANNELS).
3. Dupe line art, place on top, mult blend mode.
4. Color stuff under mult (layers in a tiff file)
5. Save as/Save a copy.

I can check include alphas but the subsequent TIF save dialog no longer allows the save transparency option. If I bring it into After Effects, the alpha is recognized as present (defaults to Straight/Unmatted) but there is no transparency. I have an old project that used an alpha channel to mask elements in AE so they can be placed over the layout/background. On a whim I opened that old project and all the alphas no longer work-- same deal, the file interpretation defaults to Straight-Unmatted, but there's no transparency. The whole project, 50+ shots is all broken. The files are online and interp set to straight/unmatted, but the comps don't recognize transparency.

A workaround I've found is to merge all the TIFF layers (if present) and add a spot mask, or a blank BG layer in the TIF + clipping mask works too-- but the whole purpose of an alpha channel in my case is to have a single master transparency embedded in the file-- Preferably one alpha-- that can be used for compositing. I don't want to be forced to merge color/beauty layers before comp, and I'd prefer not to have to copy/paste spot masks to all layers when I'm dealing with thousands of layered images.

Is this a bug? What changed?

[OussK]

Why TIFF? why you don't try to use PSD files since I think it's better for AE.

[Martell]

Good Q, these are scans that come in as TIFF. I've always used TIFF as it's a standard that's great for uncompressed images. It's always carried an alpha over to AE without problems until now. Additionally, when importing to AE, PSD's must be merged, which seems fine but if you have a shot that's 200+ images long, that's 200 dialogue boxes to check yes or hit enter to merge. Maybe that can be turned off or set in prefs, but general rule of thumb for animation: Best to avoid import dialogues whenever possible. Plus I'm not sure how blend modes will be dealth with when merging in AE. Hope that's clear, I try to avoid PSD for those reasons.

I tested saving these TIFs as a .PSD and it worked in one instance (alpha recognized in one set of 30 frames) and didn't work for another. That's almost even more confusing. I'll double check color space and bit depth to see if that has anything to do with it.

Still frustrated that there doesn't seem to be consistency with alpha channels, and that the "save transparency" appears grayed out in the save dialogue.

[Warren Heaton]

Yeah, there's something strange happening with TIFF files saved with an Alpha.

To work around it, I have been applying a Layer Mask that shows as expected in After Effects.

- Warren