Soft Proofing with Printer Profiles

[dmerger]

I've downloaded several printer profiles from several labs.  They say that their profiles are for soft proofing only.  When I use the profiles for soft proofing, I get different results depending on the rendering intent I select as well as whether I choose black point compensation.  If the profiles are solely for soft proofing, how do I determine which rendering intent to use and whether I should use black point compensation?  I'll try to ask this question of a couple of labs, but maybe someone on this forum already knows the answer.

[dandill]

If the profiles are solely for soft proofing, how do I determine which rendering intent to use and whether I should use black point compensation?
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My understanding is that perceptual takes care of black point and so with perceptual, black point should *not* be check.

My understadning is that with relative colorimetric, however, black point should *be* checked.

Assuming your mintor is properly calibrated and profiled, you can toggle soft proof to see which combination works best. In my case, I find that the answer is image dependent, *and* profile (paper/printer) dependent.

[pfigen]

If the profiles are for soft proofing only, how are you or the lab supposed to make the actual conversions to the printer space? Most current profiling packages make profiles that have very accurate soft proofing for all of their rendering intents and black point compensations. Most images convert best using Relative Colorimetric and BPC on, but there are exceptions.

[dmerger]

I've already sent an e-mail to WCI asking them the very question you raised, Peter.  I haven't received a response, yet.

One on line lab that I've used is Elco, which also has a profile solely for soft proofing. Elco is very clear that, when using their profile for soft proofing, to set it up with perceptual and no BPC.  Perhaps Elco just converts all files with that one setting.  In any event, with my photos without gamut problems, that soft proof and the actual prints match my original aRGB file (viewed on my calibrated monitor) very closely.

Dan, as you now probably realize, I'm struggling with what settings to use when soft proofing so that my soft proof corresponds to the actual conversion done by the lab.  It's not a question of what looks better.  It's what matches what the lab will do, since I don't make the actual conversion, the lab does.

[Chris_T]

I've downloaded several printer profiles from several labs.  They say that their profiles are for soft proofing only.  When I use the profiles for soft proofing, I get different results depending on the rendering intent I select as well as whether I choose black point compensation.  If the profiles are solely for soft proofing, how do I determine which rendering intent to use and whether I should use black point compensation?  I'll try to ask this question of a couple of labs, but maybe someone on this forum already knows the answer.
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I soft proof with canned profiles from Epson, etc. and print on my 2200. With each profile, how a soft proof (and pirnt) looks when changing rendering intents and/or BPC depends a lot on the image itself. With some images, the differences in soft proof (and print) when changing rendering intents and/or BPC are minor. These are typically images dominated by pastels without extreme highlights/shadows or saturated colors. But with some other images, the differences can be significant. After a while, I get the hang of what to use with different kinds of images.

When in doubt or with a critical image, I will soft proof with different settings and pick the "best" one to print. Depending on how the print turns out, I may have to iterate the process. And that's just with one profile. Change the profile, and the iterations get even bigger.

If I were to use an outside lab, I would do something similar. I would send the best print to the lab and tell them that's what you want, and how you set the profile's rendering intent and BPC.

[dandill]

Dan, as you now probably realize, I'm struggling with what settings to use when soft proofing so that my soft proof corresponds to the actual conversion done by the lab.  It's not a question of what looks better.  It's what matches what the lab will do, since I don't make the actual conversion, the lab does.
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I do now see--thanks.  Looking around the WCI site I found

[a href=\"http://www.westcoastimaging.com/wci/page/info/preflightinfo.htm]WCI Preflight Specifications[/url]

I hope this is a help.

Dan

[sergio]

The rendering intents are different way s to deal with the out of gamut colors.
Relative Colorimetric is an intent that simply clips the out of gamut colors and in their place puts the nearest in gamut color to those clipped. And it doesn't take into account the white of the printing stock base.

Perceptual intent what it does is that it compresses all the colours until the out of gamut colours are "in gamut". This is best if you want to preserve the relationship between colours.

Absolute Colorimetric is the same as RelCol except that it takes into account the printing stock white base. So if your stock is slightly warm, this intent will put small yellowish dots where pure paper white would be in your proofs. This way you can see how it is going to print on a specific stock. Be aware that you have to trim the proof's own white borders before evaluating them.

Saturation is used basically to print charts and pies and that kind of stuff.

It is your call what you want to do with your colour. There is no correct answer.

The profile you softproof has to be the printing profile otherwise you will be softproofing something else. And it is recommended to leave Black Point Comp on.

Sergio

www.sergiobartelsman.com