When I try to do this I usually set Photoshop to an sRGB working space,
then in Nuke before each merge I use a ColorSpace node to convert to sRGB,
then I do the Merge, and then I use another ColorSpace node to convert back
to Linear. I'm not in front of Nuke at the moment, but if memory serves
that managed to give me exactly what photoshop does.
Ron Ganbar
email: ron...@gmail.com
tel: +44 (0)7968 007 309 [UK]
+972 (0)54 255 9765 [Israel]
url: http://ronganbar.wordpress.com/
2012/3/8 Simon Björk <si...@stillerstudios.se>
> 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 <rlit...@rslittle.com>
>
>> 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
>>
>
>
>
> --
> --------------------------------
> 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
