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 <richb...@mac.com> 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 gradients are squashed in some areas and not as > "spread out". > > The ProEXR manual does speak about this kind of problem and suggests > bringing in the layers unpremultiplied and using Levels adjustments on the > layer masks only of each layer before changing the bit depth. With some > trial and error, I have been able to find some values that will *almost* > work. However, the levels adjustment values are not the same for each layer. > And, it still does not look quite right. > > Photoshop *will* produce the correct result, however, *if* we choose to > Merge the layers before doing the 32-->8 conversion - but that's not what we > need - we need the layers... > > So, for the moment, we are going to try and see if we can live with > individual Levels adjustments for each layer in Photoshop, prior to the bit > depth conversion. That may be the path of least resistance - but it sure > ain't pretty! (8^P > > So, Adrian, I hope that explains things a bit better. if you have any > suggestions, I would love to hear them! > > Thanks, > > Rich > > > Rich Bobo > Senior VFX Compositor > > Mobile: (248) 840-2665 > Web: http://richbobo.com/ > > "Man has been endowed with reason, with the power to create, so that he can > add to what he's been given." > - Anton Chekhov > > > > > > On Mar 7, 2012, at 6:24 PM, Adrian Baltowski wrote: > > Hi > > I want help or advise you something but I don't fully understand your > workflow... > You can of course make color conversion in nuke. Nuke is brilliant software > to make such a conversions BUT.... What next?? You cannot export layered > tiffs out of Nuke (at least not in usable form). Do you want to export > layers as separate tif files? > If you could explain your workflow then we could advise you more. > > > > Best > Adrian > > > W dniu 2012-03-07 16:33:54 użytkownik Juan Galva <juan.ga...@gmail.com> > napisał: > > keep us posted, please! > > On 7 March 2012 16:27, Richard Bobo <richb...@mac.com> wrote: >> >> Thanks, Julik, Andy, Diogo and Simon for your suggestions, ideas and >> questions... >> >> After trying a number of things and reading some more about the way ProEXR >> and Photoshop handle things, we're going to try to make our tweaks in Nuke >> and let Photoshop do whatever it does. It may take a few rounds of tweaking >> and converting to see just what we need to do on the Nuke side to make it >> come out the way we want on the Photoshop end. However, it seems like there >> are just too many variables there. So, we'll not try to fight it... (8^ >> >> Thanks for your help! >> >> Rich >> >> >> Rich Bobo >> Senior VFX Compositor >> Email: richb...@mac.com >> Mobile: 248.840.2665 >> Web: http://richbobo.com >> >> >> On Mar 07, 2012, at 07:00 AM, Simon Björk <si...@stillerstudios.se> wrote: >> >> In what application are you comparing the result of the TIFFs? Nuke or >> Photoshop? I believe Photoshop use linear light math when in 32bpc and in >> that case, the blending of layers (and brightness) will look different if >> you change your project to 8 or 16-bit. >> >> >> >> 2012/3/7 Julik Tarkhanov <ju...@hecticelectric.nl> >>> >>> >>> On 7 mrt 2012, at 01:51, Rich Bobo wrote: >>> >>> The problem is that we need to get 8 bit layered TIFs out of Photoshop. >>> >>> I think the first problem is that the Photoshop blending is profoundly >>> affected by the bit depth. >>> The second problem is that if Nuke does a 1D lookp table conversion from >>> one kind of RGB to another >>> (including bit depth upgrades), Photoshop goes via Lab so what is >>> happening is more like to a 3D LUT. >>> >>> What happens in your case is that probably Photoshop is converting the >>> layers first, and then the result of the blending >>> modes changes the way the images look. Maybe it's an issue with layer >>> mask and front unpremultiplication and conversion. >>> >>> For me the first thing to check would be the PS profile settings for >>> 8-bit RGB. Also, where do the discrepancies occur the most? >>> Blended layer edges? Maybe your workflow needs to be related to manually >>> unpremulting layers by the layer transparency and >>> preadjusting the transparency grays... >>> -- >>> Julik Tarkhanov | HecticElectric | Keizersgracht 736 1017 EX >>> Amsterdam | The Netherlands | tel. +31 20 330 8250 >>> >>> cel. +31 61 145 06 36 | http://hecticelectric.nl >>> >>> >>> >>> >>> _______________________________________________ >>> Nuke-users mailing list >>> Nuke-users@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ >>> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >> >> >> >> >> -- >> -------------------------------- >> Stiller Studios >> Lidingö/Sweden >> >> Simon Björk >> Stiller Studios >> +46 (0)8 555 23 560 >> Ekholmsnäsvägen 40, S-181 41 Lidingö >> si...@stillerstudios.se >> www.stillerstudios.se >> >> find us: >> http://www.eniro.se/query?search_word=stiller+studios&geo_area=liding%F6&what=all >> >> >> _______________________________________________ >> Nuke-users mailing list >> Nuke-users@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ >> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >> >> >> >> _______________________________________________ >> Nuke-users mailing list >> Nuke-users@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ >> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > > > > > -- > > Y ella dijo: "La ilusión mueve el mundo" > > > _______________________________________________ > Nuke-users mailing list > Nuke-users@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > > > > _______________________________________________ > Nuke-users mailing list > Nuke-users@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users _______________________________________________ Nuke-users mailing list Nuke-users@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
