tainted_heart opened this issue on Sep 06, 2009 · 14 posts
tainted_heart posted Sun, 06 September 2009 at 8:39 AM
I'm working in PPro, but this probably applies to all versions of Poser. If I understand correctly, gamma correction is used to adjust the luminance of an image due to differences in monitors. This gives a more consistant appearing image regardless of what monitor it's viewed on. My question is, if an image is being rendered for print, should gamma correction be turned of?
It's all fun and games...
Until the flying monkeys attack!!!
adp001 posted Sun, 06 September 2009 at 8:54 AM
Yes.
Color correction is done from the prepress-service according to there needs. Just make sure your image has no rgb(0,0,0) and/or rgb(255,255,255) (no pure black or white), if your images are made for offset-printing.
bagginsbill posted Sun, 06 September 2009 at 9:20 AM
I don't do print, so take my thoughts with a grain of salt. I'm answering "ab initio".
I imagine that print shops expect to be asked to print photographs from digital cameras.
Digital photos are encoded as sRGB color space images, same as the renders we produce with GC.
Therefore, I conclude they can deal with GC renders.
It's a simple conversion to go from one color space to another. What is not so simple is the gamut - i.e. some color spaces can represent colors that cannot be represented in other color spaces. But you know that already. The important thing to note is that the linear space and the sRGB space have the same gamut.
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LaurieA posted Sun, 06 September 2009 at 11:14 AM
Yes, it might be a good idea to check your rendered image inside a program such as Photoshop and check for colors that will be out of gamut. Since Poser only uses RGB and offset printers require CMYK, there might be a few problem areas. Might. That depends on the press and whether it's a 4 color or 6 color (some presses use orange and green inks now, in addition to the standard cyan, magenta, yellow and black).
Laurie
wolf359 posted Sun, 06 September 2009 at 11:38 AM
Hi Left the print/prepress business in 2007 after 18 years
Honestly
Most modern print shops dont even do hands on color managed prepress anymore,unless they are handling a Major brand and need %100 color accuracy (Coca Cola red ,Ford Blue, Fedex purple) Etc.
But in most cases they use a one size fits all Digital Rip software and just thrown everything at it and let the rip engine sort it out.
so your concern about poser gamma setting at render time are pretty much moot.
Cheers
LaurieA posted Sun, 06 September 2009 at 12:32 PM
Yep, what wolf359 says is very true. Unless of course you live where I live and most print shops are still equipped like they were in the 70's....lol.
Last place I worked I tried like mad to get them to invest in a digital rip, but it was all falling on deaf ears I'm afraid. That would cost money ;o).
Laurie
wolf359 posted Sun, 06 September 2009 at 12:54 PM
Quote - Yep, what wolf359 says is very true. Unless of course you live where I live and most print shops are still equipped like they were in the 70's....lol.
Film Processors ,Stripping celluloid up on "Golden rod", begging the client to backsave their vector art files to Illustrator-8 because the owner is too cheap to upgrade your Adobe tools..ARRGHH!!
Nope I cant say I miss those days
Cheers
LaurieA posted Sun, 06 September 2009 at 1:06 PM
Quote - > Quote - Yep, what wolf359 says is very true. Unless of course you live where I live and most print shops are still equipped like they were in the 70's....lol.
Film Processors ,Stripping celluloid up on "Golden rod", begging the client to backsave their vector art files to Illustrator-8 because the owner is too cheap to upgrade your Adobe tools..ARRGHH!!
Nope I cant say I miss those days
Cheers
When I first got to the place the first thing I made them do was to get me a copy of Photoshop and QuarkXpress. They were editing and creating prepress files in....gulp....Adobe Acrobat with PitStop. Then expected me to edit bitmap images in Illustrator??? At least they met me that far ;o). I couldn't convince them to do anything further, so I was still hand-punching negatives and exposing press plates on a vacuum table. At least they didn't make me do hand layout with an xacto knife and a hot wax machine ;o). Hand-pasting every page number was a real drag...lol (another job).
Laurie
jerr3d posted Sun, 06 September 2009 at 2:50 PM
at least in my case most of my Poser renders seem to have a color cast, usually red, in them. try taking any Poser render into Photoshop and use Auto Levels and watch it turn too Cyan. I always do color correction in detail, and then ask for a test print, or at least a small print before doing a poster size.
GeneralNutt posted Sun, 06 September 2009 at 3:14 PM
Wait your print shops are going about this all wrong, you need to have special inks. Ink companies would be more than happy to make them custom for the press. Really we are board stiff.
As a bonus I make more cash that way and buy more here. ;)
tainted_heart posted Sun, 06 September 2009 at 3:54 PM
Quote - Digital photos are encoded as sRGB color space images, same as the renders we produce with GC.
You know, I forgot about that. That answers my question. Thanks BB and everyone else for your help and advice!
It's all fun and games...
Until the flying monkeys attack!!!
MistyLaraCarrara posted Fri, 11 September 2009 at 10:01 AM
oh wow. I remember going into the closet under the stairs (as my darkroom), unwinding the film and trying to fit it on to the spindle before putting it the developing solution. I didn't even have the enlarger, my pictures came out the same size as the negative.
oh where is my first brownie camera. has to be in the attic somewhere.
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cspear posted Fri, 11 September 2009 at 11:27 AM
The real answer to this conundrum is a color-managed workflow, which is tricky as no 3D modelling / rendering apps have color management support - except lightwave, through an optional plug-in.
However, if - like most people - you create your scenes and render them so that they look good on your monitor, there is a way to color-manage the renders, assuming you have a colour managed image editing application - I think most of them are these days.
Step 1 is to calibrate and profile your monitor. If you have hardware for doing this, great. If not, try the links here. Those tools will help you build some sort of profile. If you have Photoshop, you should have Adobe Gamma in your Control Panels - use this if available. The important thing is to end up with an ICC profile for your monitor: this describes how your monitor specifically displays color and deals with brightness and contrast. Name the profile something meaningful: 'MyMonitor_dd/mm/yy' for example. The bit at the end is the date: perform calibration and/or profiling regularly.
Step 2 is to open your render in (for example) Photoshop. It should warn you that the image file has no attached profile. If it doesn't, set up your prefs so that it does. Then you need to assign your monitor profile to the image. Then you can convert it to your favoured RGB colour space: sRGB, AdobeRGB or whatever. If given the choice, select perceptual rendering intent. You've then color-managed the render. Only at this stage should you make any mild corrections or tweaks. When you save the file, make sure the color profile is embedded. Don't mix up assigning a profile and converting to a profile, they are different things!
What you do next depends on what kind of print service you're going for: the only advice I can give is, if in doubt, convert the file to sRGB (if it isn't there already).
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hborre posted Fri, 11 September 2009 at 1:45 PM
Good advice to follow. Thanks.