Soft Proof setup

[bellimages]

I am curious about the settings for soft proofing. If I use select "Preserve RGB Numbers" the proof looks way dark. If I select "Black Point Compensation" the colors look right on the money compared to what I see on my NEC screen. Which should I be using prior to making an initial print?

[walter.sk]

I am curious about the settings for soft proofing. If I use select "Preserve RGB Numbers" the proof looks way dark. If I select "Black Point Compensation" the colors look right on the money compared to what I see on my NEC screen. Which should I be using prior to making an initial print?

For softproofing, I never check the "Preserve RGB Numbers."  I do check Black Point Compensation, and Simulate Paper Color.  I switch between Perceptual and Relative Colorimetric rendering intents to see which looks closer to the original.

I then do Image>Duplicate to get an independent version of the non-softproofed file.  Then, Windows>Arrange>Tile to have the softproofed version on the left, the duplicate of the original on the right.  You will see quite a difference, as the one on the left will have its white point simulate that of the paper.

Then, I add several adjustment layers to the softproofed file, usually adjusting curves and hue/saturation as well as a Color Balance layer if needed.  The idea is to recapture as much as possible of the dynamic range and color so as to resemble the duplicate original file.

Michael and Jeff Shewe have a great tutorial, From Camera To Print, on the LL home page.  The section on color management and softproofing is very clearly presented.

[BobFisher]

In very simplistic terms, the soft proof dialogue is giving you a visual representation of what would happen if you converted the image to the respective print profile.  When you convert to a different profile, the RGB numbers are altered in order that the visual colours remain as close as possible to the original.  For example, a colour like R219, G57, B92 in AdobeRGB may need to be R200, G62, B100 in sRGB in order for the colours to stay visually the same (I made those numbers up so don't go trying it and telling me it's wrong  ).  

By checking Preserve RGB values you're overriding that profile conversion and getting a visual representation of what will happen to the colours if they're not properly mapped from the source profile to the destination.  The same as doing an Assign Profile.

You can test this yourself.  Open an image, duplicate it.  Convert one to your chosen paper profile using Edit>Convert to Profile.  Now go to the second and proof it with the same profile.  Make sure BPC is the same in both (both checked or unchecked) and turn Simulate Paper Color off in the proof setup.  They should look the same.  Now do the same by assigning the profile to one via Edit>Assign Profile and in the proof setup check Preserve RGB with Simulate Paper Color turned off.

In other words, Convert to Profile/Preserve RGB unchecked = Good and Assign Profile/Preserve RGB checked = Bad.

[digitaldog]

Preserver Color Numbers shows you what the current document would look like if you did NOT use the profile when printing. Not useful for most users. Kind of useful if someone hands you a CMYK document and you wanted to see “how would these CMYK values look if I sent it directly to the press”? If really ugly, you want the original RGB doc and reconvert. Otherwise, keep that check box off.

This may help too:
http://www.ppmag.com/reviews/200409_rodneycm.pdf
http://www.ppmag.com/reviews/200411_rodneycm.pdf

[hsmeets]

........Then, I add several adjustment layers to the softproofed file, usually adjusting curves and hue/saturation as well as a Color Balance layer if needed.  The idea is to recapture as much as possible of the dynamic range and color so as to resemble the duplicate original file.

I previously did the same, adding adjustment layers to bring back the softproof looking similar to the original. Because of what I photograph I used the same adjustments very often. So I saved the presets in photoshop and recalled them on images.

I use the spyderprint to make, occasionally, a profile. After creating my first profiles I was dissapointed as the softproof en print was a somewhat darker and colorbalance shifted a bit and thus still had to make adjustments in photoshop.

A year long it never occured to me  (Read That Fine Manual) that the spyder software also allows you to adjust the measured (brightness, contrast, colobalance, etc) data before the profile is created.....so I did the correction in spyder (lighter and some colorbalance  tweaks) and now the profile takes care of that and softproof/print looks much more like the origional file. The need for adjustment layers has lessened a lot.

From the same measurement file aI created 2nd profile targeted at producing a cool to neutral B&W print by tweaking it somewhat different.