color settings edit in photoshop

[bluskool]

I have [read|http://www.colorwiki.com/wiki/Color_Management_Myths_21-25] (myth # 23) that changing your color settings in Photoshop (edit>color settings>custom cmyk) is not recommended because photoshop is not an icc profile editor. Can anyone tell me what is happening when you make adjustments to your color settings this way? I don't have a profile editor and I have been making adjustments in this way. Is this a bad idea? If so, why? I tried to attached the color settings file, but it is not working.

 

[rich apollo]

Re: color settings edit in photoshop

This is a bad idea. You're not editing profiles, you're generating new ones with an outdated color engine. The profiles you're generating aren't based on the color reproduction of any device, so it's a bit of a black art.

What kind of edits are you needing to make, and to what profile?

rich

 

[bluskool]

Re: color settings edit in photoshop

Our printer uses a web press to print our newspaper, so I choose North American General Purpose 2 from the settings menu, then turn off black point compensation, then choose custom CMYK and change ink colors to SWOP (newsprint), limit the black ink to 85 and the TAC to 240.

That is all I have done so far. However, our big problem is that there is more dot gain in the shadows than is shown on screen. We make the shadows lighter to compensate, but it is always a guessing game. Sometimes photos are not lightened enough and the shadows fill in and hide detail, and sometimes photos are lightened too much and they look flat and void of detail. I want the soft proof to look closer to the print than it does so there is not as much guessing ( and errors).

By the way, our printer does not have their own press profiles.

 

[meddington]

Re: color settings edit in photoshop

>Our printer uses a web press to print our newspaper, so I choose North American General Purpose 2 from the settings menu, then turn off black point compensation, then choose custom CMYK and change ink colors to SWOP (newsprint), limit the black ink to 85 and the TAC to 240.

As Rich pointed out, as soon as you go to Custom CMYK, you throw ICC profile in your Color Settings away, and begin generating another based on an antiquated color engine. If you're shooting for a newsprint profile, have you tried SNAP?

http://www.color.org/registry/SNAP_2007.xalter

 

[disbellj]

Re: color settings edit in photoshop

You've had the best suggestion yet Michael. If the printer prints to the SNAP standard, then this profile would be the best to use. Since the printer doesn't make their own profile, this is still the best to use (not knowing their actual printing condition, which is defined in the ICC profile). Wish I would have thought about that earlier. Sometimes can't see the forest for the trees.

Don

 

[bluskool]

Re: color settings edit in photoshop

Thank you. This issue has been bothering me for months and you just answered my main question with one link. I tried out that profile and it matches much closer. You just made one small community newspaper look better. So, I am guessing that loading SNAP icc profile in grayscale would help with the black and whites too, right?
Would I be messing anything up by turning off black point compensation?
And should I choose embed profile when saving a photo as an EPS?
Thank you again.

Dan R.

 

[disbellj]

Re: color settings edit in photoshop

About loading that SNAP profile into grayscale. Yes, that's what you want to do. When it gets loaded into grayscale, it will say "Black Ink - profile name". Then click on it again and save as a new name (will be a grayscale profile now that's portable just like the CMYK profile). You'll use this grayscale profile in your color settings as grayscale profile.

I leave Black Point Compnesation on (it's on by default). Someone may be able to tell us why you would want it off.

If want to do color management on the CMYK or grayscale down the line (changing numbers in a program after Photoshop), then yes you'll want to embed the profile. Otherwise no. If you use the same color settings in all Adobe programs, then there will be no problem either way, because CMYK or grayscale numbers won't change unless an embedded profile is embedded in Photoshop, and then honored/used in the program down the line, and the output profile from the program down the line is different. Unless all three of those apply, CMYK or grayscale numbers won't change.

Don

 

[rich apollo]

Re: color settings edit in photoshop

You can also go to

http://www.ifra.com/website/webreg.nsf/persondownload?OpenForm&ISO_downloads_USA

for an "ISO" newspaper profile built by IFRA (German newspaper printers association - sort of the SNAP of northern Europe, I guess).

> {quote:title=bluskool wrote:}{quote}
So, I am guessing that loading SNAP icc profile in grayscale would help with the black and whites too, right?
> Would I be messing anything up by turning off black point compensation?
> And should I choose embed profile when saving a photo as an EPS?

Are you talking about turning off black point compensation in your Color Settings? Doesn't really matter. These settings only come into play if you:

a) Open an image with no profile embedded. The image will sort of have the relevant default profile assigned in the background. The profile is not actually assigned, but is assumed. Photoshop needs this for display purposes, and for performing color transforms from color space to another.

b) If you move between color spaces by going Image > Mode (which is a no-no) - don't work like this. Use Edit > Convert to Profile. This way all the controls are right there at the moment you need them.

I tend to keep Black Point Compensation on at all times.

> {quote:title=bluskool wrote:}{quote}
> And should I choose embed profile when saving a photo as an EPS?

I'd question your use of EPS at all. EPS is dying. The only purpose it serves at this point is vector based output of Photoshop elements from page layout applications. All other functions can be handled in other formats.

rich

 

[disbellj]

Re: color settings edit in photoshop

"I'd question your use of EPS at all. EPS is dying. The only purpose it serves at this point is vector based output of Photoshop elements from page layout applications. All other functions can be handled in other formats.

rich"

Rich,

Does saving a PDF out of Photoshop do this as well now (keeping type as vector out of Photoshop when PDF placed in InDesign or Illustrator and output)? I remember testing this, but I can't remember what the outcome was (actually I think that the type turned to image but I'm hoping I'm wrong).

Don

 

[leonardr]

Re: color settings edit in photoshop

Photoshop PDF's keep the type as text, as you would expect.

What you may be thinking of, however, is that you can NOT use the
Acrobat Touchup tool to edit this text. This is because the text is
drawn using as a clipping path (against a raster fill), rather than
standard filled text. Touchup doesn't support editing such text.

Hope that clears things up.

Leonard

 

[bluskool]

Re: color settings edit in photoshop

> {quote:title=disbellj wrote:}{quote}
> I leave Black Point Compnesation on (it's on by default). Someone may be able to tell us why you would want it off.

I turn it off because it just seems to be closer to reality than when it is on. When black point compensation is checked, the image looks better and more detailed (especially in shadows), but when it prints the shadows that looked good on the screen fill in. With BPC on, the shadows on screen look filled in. The trade-off is that the on screen image (with BPC on) has a lot of noise in the shadows, but it does not print that way.
This is all based completely on speculation and observation. Also, this speculation is based on web newsprint and I can't say that it makes a difference for any other type of printing. I could not even tell you what BPC actually does aside from making the image look different.

Dan R.

 

[disbellj]

Re: color settings edit in photoshop

Thanks Leonard. That does clear it up. I remember that now that you've said it.

Don

 

[meddington]

Re: color settings edit in photoshop

>Would I be messing anything up by turning off black point compensation?

I think the general rule for black point compensation would be if your converting from a low L* to a higher L* (Adobe RGB to SNAP), you'll want BPC on to preserve shadow detail.

For moving from a high L* to a low L* (SNAP to aRGB, or GracolCoated, or damn near anything else for that matter) +where the intent is to maintain the look of the original+ , you'll want BPC off, otherwise you'd be mapping a weak L* value to the darker L* value that isn't achievable from the source ICC profile. This would make the image look more dynamic than the original.

So it depends on if the intent of the conversion is to maintain the originals appearance or not.. If your wanting to use an image tagged with a SNAP profile for commercial sheetfed and you want to take advantage of the higher dynamic range, use BPC. If you want to maintain the original look of the SNAP image, do not use BPC.

This becomes more of an issue when proofing. If you have images tagged with SNAP, and are proofing them to an inkjet printer using a ReL Col with BPC conversion, your proof will have darker L values than the process its supposed to be simulating. Most will be using absolute rendering for proofing, so this shouldn't be an issue. And of course, Photoshop's default preview will be without simulating paper color or black ink, and so will look optimistic.

 

[bluskool]

Re: color settings edit in photoshop

> I think the general rule for black point compensation would be if your converting from a low L* to a higher L* (Adobe RGB to SNAP), you'll want BPC on to preserve shadow detail.

So does BPC improve shadow detail in my soft proof or the final print? If it is only preserving detail in my soft proof, then why would I want it, since the idea is to get a soft proof that looks closer to the final?


> And of course, Photoshop's default preview will be without simulating paper color or black ink, and so will look optimistic.

Using simulate paper color does not seem to be very accurate either.

Dan R.

 

[meddington]

Re: color settings edit in photoshop

>So does BPC improve shadow detail in my soft proof or the final print?

Both...BPC will map the black point of the source profile (aRGB for example) to the black point of the destination profile (SNAP), and therefore maintain shadow detail. Without BPC on during this conversion, the black values of the source profile that are not capable of being reproduced in the destination profile are clipped...detail lost.

Now, when softprofing an image, in this case tagged with a SNAP profile, Photoshop by default will map the black point of the image (determined by its embedded profile) to that of the monitor profile that's displaying the image (this despite your Color Setting preferences). This is BPC, but in reverse...going from a light black to a dark black as monitors generally have a higher dynamic range (blacker blacks) than the print process they're supposed to be emulating. Therefore, on screen your SNAP image looks nice and juicy, but flat when printed.

The technically correct way to softproof would be to go to View/Proof Set Up/ Custom and select "Simulate Black Ink" with your SNAP profile, which simulates a relative colorimetric rendering +without+ BPC for the display, and hence, a preview truer to the final print. Simulate Paper Color will yeild an absolute colorimetric rendering for the preview, taking paper white into account.

So in short, you defintely want BPC on during a conversion from RGB to CMYK, but for an accurate softproof of that CMYK, you'll want no BPC for the "conversion" from CMYK to the monitors RGB....and this doesn't happen automatically in Photoshop.

 

[meddington]

Re: color settings edit in photoshop

>Using simulate paper color does not seem to be very accurate either.

I have nothing printed toward SNAP to comapre to here, but there are any factors that can detract from the perceived accuracy of a softproof., not the least of which would be lighting and viewing conditions, and the accuracy of the monitor profile Other issues could be the accuracy of the hard copy proof or how well the CMYK profile represents the final printing that the softproof is being compared to, how much sleep you've had or how much you've had to drink the night before, what gender you are, your eyes adapting to the white points of other dialog boxes or object in the immediate area, ect.

 

[disbellj]

Re: color settings edit in photoshop

"So in short, you defintely want BPC on during a conversion from RGB to CMYK, but for an accurate softproof of that CMYK, you'll want no BPC for the "conversion" from CMYK to the monitors RGB....and this doesn't happen automatically in Photoshop."

So in short, we can't really get an accurate soft-proof of RGB, so we need to convert in Photoshop to the CMYK profile, and then soft-proof (and then if changes needed color correct CMYK while soft-proofing CMYK)?

Don

 

[disbellj]

Re: color settings edit in photoshop

So would he check 'Simulate Paper Color' or not when soft-proofing?

Don

 

[meddington]

Re: color settings edit in photoshop

>So in short, we can't really get an accurate soft-proof of RGB, so we need to convert in Photoshop to the CMYK profile, and then soft-proof (and then if changes needed color correct CMYK while soft-proofing CMYK)?

You can get the same preview for an RGB image as a CMYK., but the proof setup settings are different. For an RGB, go to proof setup/custom and select the destination profile, Rel Col with BPC, (to simulate the conversion from RGB to CMYK), then choose Simulate Black Ink/Paper Color. This will give an identical preview as if you convert from RGB to CMYK using Rel Col with BPC , then turning on Simulate Black Ink.Paper Color.

 

[meddington]

Re: color settings edit in photoshop

>So would he check 'Simulate Paper Color' or not when soft-proofing?

Subjective I guess...technically this is the correct manner to softprof, but it depends on how close the paper color on press is to the paper color of the SNAP profile. Not using paper white you'll get monitor white, but sometimes that's better than the paper color. Take the USWebCoatedSWOP profle for example. Can be used successfully for softproofing, but the paper color is way yellow compared to what most people use. So enter a compromise, or a profile edit of the white point.