Great that the ICC way worked for you. Darkening you say, hm... If any I would have expected it to be brighter caused by double gamma. How are you comparing the results? Also, the file must be linear otherwise it will never match Nuke.
Chris, intresting about levels gamma not beeing accurate, will look into that some more. Just a thought though, as I'm sure you already know, it will not match the gamma of Nukes grade node, as that one produce a very different result than adjusting gamma in the gamma node. Simon Den torsdagen den 8:e mars 2012 skrev Richard Bobo<[email protected]>: > Simon, > I made a linear ICC working space profile and I was able to successfully convert my 32 bit file to 8 bit with very little shifting of values. Yea! So, that was a "win" - thank you! The one wrinkle that I hadn't taken into account is that when I save out the 8 bit layered TIFF file from Photoshop - it's still in linear colorspace! And, if I do a convert to color space in Photoshop - from linear to sRGB - I still get the same darkening as before! So, I'll I've really done is to move the problem farther down the pipeline! Arrgghh... Any suggestions? > > Thanks, > Rich > > Rich Bobo > Senior VFX Compositor > Email: [email protected] > Mobile: 248.840.2665 > Web: http://richbobo.com > > On Mar 08, 2012, at 11:17 AM, Simon Björk <[email protected]> wrote: > > After, as it will make the layers blend in linear light instead of sRGB. The overall gamma will be the same as the sRGB viewer lut you have in Nuke. Although, you might introduce problems with banding as your really bending the colors of 8-bit. Of course you will also clamp values above 1. It might be better to do your compositing in sRGB space in Nuke as other suggested, but it's worth a try. Essentially, this would be somewhat the same thing as using a linear ICC profile in PS. > > 2012/3/8 Richard Bobo <[email protected]> > > Simon, > Are you saying that the .4545 levels effect on the layer masks and the overall 2.2 gamma adjustment should be done before the 32 to 8 bit depth conversion or after...? > Thanks, > Rich > > Rich Bobo > Senior VFX Compositor > Email: [email protected] > Mobile: 248.840.2665 > Web: http://richbobo.com > > On Mar 08, 2012, at 03:46 AM, Simon Björk <[email protected]> wrote: > > Look here to create a linear ICC profile: http://fnordware.blogspot.com/2008/05/making-linear-icc-profile.html. With that set as your working space, you should be able to get correct blending. > If you only have a couple of layers, you could try adding a Levels effect and set gamma to 0.4545 to each layer. On the top of your layers you would then need to set an adjustment layer with a gamma of 2.2. > /Simon > > 2012/3/8 Randy Little <[email protected]> > > because you are using blend modes in photoshop that do not support > float math(s) AND/Or you your working space ICC is not set up right. > > Randy S. Little > http://reel.rslittle.com > http://imdb.com/name/nm2325729/ > > > > > On Wed, Mar 7, 2012 at 20:43, Richard Bobo <[email protected]> wrote: >> Adrian, >> >> Thanks for wanting to help! >> >> Here are the parameters: >> -- CG render passes, comped and beautified in Nuke (auto work)... >> -- Ultimate deliverables for client are layered 8 bit TIFF files with alpha >> out of Photoshop (different parts of vehicle)... >> >> In order to ease the workload, we are trying to render layered files out of >> Nuke that get loaded into Photoshop. There is some automated work that is >> done with a recorded macro/droplet in Photoshop and the end result is our >> client-ready 8 bit layered TIFF .psd file. >> >> It would be *perfect* if we could render out an 8 bit layered file of some >> kind from Nuke. The only reliable layered file format that I know of coming >> out of Nuke is EXR. And, I don't think Nuke will produce a layered TIFF or >> DPX that Photoshop can read properly. I could be wrong about that and if I >> am, I'd love to know how to do it! Also, EXR output does not allow 8 bit, as >> far as I can tell. So, we've tried 32 and 16 bit EXRs. >> >> The OpenEXR Photoshop plugin does a nice job of loading the EXR files, >> either as premultiplied layers with transparency or as unpremultiplied, >> separated layers for fill and alpha. The look of the layer comp in Photoshop >> matches Nuke as long as we stay in 32 bit linear space in Photoshop. >> However, changing the bit depth to 8 bit results in a general darkening of >> the image layers and a different "gamma look" to the transparent areas. In >> other words, the nice linear gradien -- -------------------------------- Stiller Studios Lidingö/Sweden Simon Björk Stiller Studios +46 (0)8 555 23 560 Ekholmsnäsvägen 40, S-181 41 Lidingö [email protected] www.stillerstudios.se find us: http://www.eniro.se/query?search_word=stiller+studios&geo_area=liding%F6&what=all
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