Profiling a Lambda

[Jeff-Grant]

A friend has acquired a Lambda for his business. He has asked me for help on profiling it. The story as I understand it is:
1. The Lambda can be adjusted for various media but there is no equivalent to a profile that can be used with it.
2. The way to use it is by printing a target with the Lambda set as desired
3. Scan the target and build a profile
4. Assign the newly created profile to the monitor and dedicate that monitor to the Lambda so that whatever is on it will be what will be printed
5. Distribute the profile to customers as a softproofing profile.

[RHPS]

You're OK up to step 3 - building the profile - but step 4 is a bit confused. Firstly, you can't assign the profile to the monitor, you can only assign it to an image. When you assign it to an image your (correctly profiled) monitor will show you how the printer interprets the RGB values in the file - in other words it will show you how the printer would print it without colour management. Assigning the profile will not change the RGB values in the file.

The profile can certainly be used for soft-proofing but it can be used to colour manage the printer too. To do this you just need to convert the image file to the printer profile. This will change the RGB values in the file so that when the converted file is sent to the printer, the printer will give the nearest colour it can to the original colour in the image.

If your friend distributes the profile to the customers they can use it to soft-proof and optimise their images. To make the printed image match the soft-proof they must convert the file to the printer profile before sending it to your friend. He then simply sends the file directly to the printer and the colour management loop is completed.

The only problem with this process is that applications like Elements don't have the ability to convert to a custom profile. There are freeware utilities around that will do this (I think Dry Creek offer one) but it's another hurdle to jump. The alternative of course is for your friend to do the conversion for every image sent to the printer.

Hope that all makes sense.

[digitaldog]

I’ve built profiles for Lambda’s for others, its certainly doable but I have no idea what settings or front end processing was used. That said, the resulting profile was used like an other output profile, for soft proofing and conversion to the output color space.

[Scott Martin]

Prior to profiling, it's essential that profiles be disabled on the workflow software and that a fresh linearization/calibration be performed. These processes do drift so having a fresh calibration prior to profiling is essential. The media settings that you are talking about are basically DMax aim points for the calibration process - those aims are different for each paper type.

I'd encourage you to profile with either Monaco Profiler or i1Profiler if possible. IMO, ProfileMakerPro and EyeOneMatch, in particular lead to disappointing results in comparison. Pay close attention to your Perceptual rending options as they are key with silver halide printing. Save your profile as a spec 2 ICC profile for this machine. Depending on their version of the host software and/or workflow software they're running you might be able to enable the profile within the workflow software so that everything is converted to the printer profile for this printer/paper combination. If their workflow software doesn't allow you to use the printer profile they'll need to *convert* (not assign) all images to the printer profile in Photoshop prior to printing.  Again, this depends on what workflow software they're using (Labtricity, ROES, DP2, etc - you didn't mention this so it's hard to know what they might be using). Looking at the bigger picture of their workflow and integrating color management elegantly is very important.

Don't assign the printer profile to the monitor! The images themselves need to be *converted* to the printer profile either in Photoshop or the workflow software. In Adobe apps you can use the profile for soft proofing by going to View>ProofSetup>Custom. Pay attention to the rendering intent and other options and save your proofing settings as a ".psf" file.

Don't distribute the profile to their customers! That leads to all kinds of problems. The lab will want to update their profiles regularly. If customers have profiles then they'll start converting the images (which isn't their job) and when profiles get updated all their customers will have outdated profiles. Instead, distribute the Adobe Proof Setup FIle (.psf) so that their customers can soft proof. That's what customers need to do - nothing more.

Lab wide color management can be a lot more complicated that it seems at first. It's important to make it elegant and fool proof. And it's also important to keep it simple for the lab's customers. I've been working in digitally based silver halide labs for over 16 years on color management issues and have great relationships with Noritsu, ZBE, XRite, Express Digital, ROES and others. There are a lot of silver halide specific tips and tricks to implement along the way. Let me know if I can help.

p.s. Your friend should so choose the paper and chemistry they use carefully as there can be significant differences between them!

[Jeff-Grant]

Thanks Folks. I suspect that I will be back with more questions but that is great to get me going.