Today’s Question: Regarding your response to the question on printer tonal range, you say to evaluate the test image under a bright light source. I wonder if one shouldn’t evaluate the test image under a light source, and at a distance, that provides a luminance value similar to that expected in the location where the print is most likely to be displayed?
Tim’s Quick Answer: In the context of evaluating the actual tonal range capabilities of your printer, I recommend using a very bright light source so you can better evaluate the print. That said, when it comes to a final print you intend to hang on the wall, it is most certainly reasonable to optimize the print based on those display conditions.
More Detail: From time to time I’ve written about an issue whereby a printer doesn’t actually render complete shadow detail in the darkest shadows, even when you’ve used an accurate printer profile to produce the print. You can compensate for this behavior by first evaluating the behavior of your printer, and then applying a compensating adjustment before printing.
You can read about the process, and download a target image used to evaluate the behavior of your printer, in an article on the GreyLearning blog here:
http://greylearningblog.com/printer-tonal-range-correction/
While it is perfectly reasonable to evaluate an individual print based on the conditions under which it will be displayed, when it comes to compensating in general for the tonal range limitations of a printer, I don’t recommend that approach.
To establish a baseline compensation that will ensure your prints contain all of the shadow detail possible, you should evaluate the test print under a bright light source. This enables you to determine the actual behavior of your printer (specific to the paper and ink combination being used with that printer) in terms of rendering shadow detail.
The result of this testing would provide you with a general compensation adjustment that could be applied to every photo you print. In cases where you know the precise conditions under which a print will be displayed, you could go a step further and evaluate that print under those conditions. You could then apply a compensation specific to that print based on the display conditions intended for the print.
Of course, it is important to keep in mind that if you apply adjustments to compensate for the specific conditions under which a print will be displayed, if that print is moved to a different location it may not look its best. The specific results depend on the lighting conditions, and in particular to how significant the differences in lighting conditions actually are.