A Computer Darkroom Tutorial

Many readers will already know that Adobe recently released an update to Photoshop CS2 (i.e. 9.01), the purpose of which was to fix a small number of performance and stability issues. Unfortunately, the update has exacerbated a previously intermittent printing problem that had apparently effected relatively   few users with the result that it's more widespread than before.

 

This problem, when it occurs, is most noticeable as banding or posterisation within a very small range of tones/colours, which typically include skin tones, the transition between yellow/orange, and some reds. It's further complicated by the fact that the effected colours seem to differ by printer model and media type. The following scanned prints are from my Epson R2400, and are based on a section of Andrew Rodney's RGB Test Print. They are presented to demonstrate the most obvious outworking of the problem on Epson Premium Glossy Paper.

 

Epson R2400 - Good Print	Epson R2400 - Bad Print

 

At time of writing the exact cause of the problem is unclear, however, I have no doubt Adobe will wish to establish the cause, and quickly affect a fix. In the meantime, users can either downgrade to Photoshop 9.0 or use the workaround described below. This workaround works on all of my Mac systems (i.e. Dual G5, Dual G4 and G4 PowerBook) and Epson printers (i.e. Stylus Photo 1200, 1290S and R2400); it's also been checked by a small sample of users who have also experienced the problem.

  28 May 2006

The actual cause of the problem described above is apparently due to a bug within Mac OSX 10.4.x that had been hot-fixed by Apple for Photoshop 9.0 (AKA CS2). Unfortunately, the hot-fix was version specific and slipped through the 9.01 testing net. You can read more about the bug here.

28 June 2006

If you're using a PowerPC (i.e. G4 or G5) based Mac, then you'll be pleased to know that Apple have just released Mac OSX 10.4.7 update, which includes a fix for the problem described in this article.  I recommend that you download and install a copy ASAP. However, as of  posting this update it appears that the fix may well not have been implemented in the Intel version of 10.4.7.

The first step of the workaround is to create a custom Proof Profile (Customize Proof Condition) for all the media types that you currently use. The example shown below is one I created to simulate my Epson R2400 printer when using a customised profile for Epson Premium Glossy paper (1). With this particular media I find that setting the Rendering Intent (2) to Relative Colorimetric is better, but other media types will work best with Perceptual. Likewise, I find leaving Black Point Compensation (3) "On" is the best option. When satisfied that the dialog is configured correctly, save the settings. Ideally, you should use a naming convention that reflects both media type and rendering intent.

Photoshop Proof  Setup

This next step is where things get interesting, and to some extent confusing. Through various tests I've found that the problem described above only manifests itself when the Print with Preview Color Handing option is set to No Color Management or Let Photoshop Determine Colors.  If Let Printer Determine Colors is chosen the problem doesn't occur. However, this latter option is more usually associated with a print workflow  that more serious Photoshop users dislike using, and it's unlikely that they'll willingly adopt it now. Fortunately, Photoshop is designed to be a lot more flexible than most applications, and the to this end you'll find that the Color Handling option has a number of alternative codepaths. Onto the next step...

 

Configuring Photoshop Print with Preview

Now, select the Proof (1) option. If you haven't used this option before it will show your CMYK Working Space profile, but don't worry about that yet. Once Proof is activated you'll see that the Proof Setup Preset (2) popup menu is also active - choose your customised Proof Profile from the available options. The final configuration of the Print with Profile dialog should be as shown below, although the names of your profiles will be different. Remember, Color Handling must be set to Let Printer Determine Colors. OK, so I accept that this option will be an anathema to many users, but it really is key to the success of the workaround.

 

Final Print with Preview Configuration

Finally on to the Print driver dialog. I've only shown the Color Management panel, but you should remember to first set the proper media type, print speed, etc. The remaining steps are the same as you would normally use when printing with media profiles and NOT those setting that you would normally expect to use when allowing the printer to manage colour matching. In other words, remember to set Color Management to OFF (No Color Adjustment) in the print driver.