Blackmagic Forum

In b4 this png (ACES cg from Nuke) would work correctly on a timeline with a straight alpha attribute.

https://www.dropbox.com/s/5cb3z805oykmqn4/DK02_012_atmosphere_v001.0056.png?dl=0

In b5 it requires the alpha channel to be turned off to work correctly.

The project is in ACES color space.

In fact it's also tiffs with alpha channels.

The files seem to be read as sRGB despite being told they're ACES cg.

It would be helpul to have confirmation from the QA guys or another user, that this is a problem, or it's not, before I revert to b4. Anyone?

Thanks in advance,
David

I can confirm some odd alpha channel handling compared to beta 4.

Peter Cave wrote:I can confirm some odd alpha channel handling compared to beta 4.

Thanks, Peter. I'm back on b4 and the ACES world is right again with with alpha channels in PNGs and TIFFs and possibly a whole lot of other things.

Hi,

I have some tests with your PGN (for test ACESxxx and B5 and very quickly done: not refining at best)

What is certain is that this .PNG is recognized with ALPHA STRAIGHT

By cons:
if one is in ACEScct, from the media Pool one "sees" the Alpha, if one is with ACEScc one does not see it (nevertheless it is there)


For the "See" I had to go to the Fusion tab and use the "Matte Control"


Anyway, ACEScc or ACEScct, in the tab color (+ Matte Control): same result.


Hope this help or does someone have a simpler solution?

Edit: "See" color TAB provided you do not call a LUT 3D viewer or 3D Video Monitor ...

Jean Claude,

The colour space of the project is ACES 1.03. The alpha in the png is not recognized correctly when its ACES is set to ACES cg which is how it's been rendered in Nuke. When in a timeline the luma values are much dimmer than they appear in Nuke. They look very much like the file is being seen as sRGB, not ACES cg.

I have flickering alpha-channel (some frames are not display alpha-channel) on any png-sequences in b15. When reinstall b14 - all work fine