[Leica] colors, screens, iMacs, laptops, and such

[reid at mejac.palo-alto.ca.us (Brian Reid)]

I have never seen any computer display costing less than $1500 (just for 
the display) that came from the manufacturer with anything close to 
proper color calibration.

I have never seen any laptop from any manufacturer whose color rendition 
is good enough that I would use it for serious editing of color 
photographs or producing color-calibrated InDesign files for printing. 
The display hardware used in laptops is just not good enough. Maybe 
someday Eizo will make a laptop, but today they don't.

I have done a lot of critical color work in my life, including making 
museum-grade prints (of other people's pictures), making 10-foot by 
20-foot color prints for trade shows, producing corporate annual reports 
for a large cosmetics company, restoring faded prints of historically 
important images, and taking pictures of my family. If you want the 
image that you see on your screen to look the same on someone else's 
screen, or look the same when printed on paper, then all of the devices 
involved need to be color calibrated. Service bureaus owning machines 
that can make 10-foot by 20-foot prints want print files with managed 
color.

This article in Photography Life, about 4 or 5 years old, is the best 
introduction I know of to the issue:

https://photographylife.com/the-basics-of-monitor-calibration

and, unlike most things you see online, its comment section is mostly 
worth reading.


This iMac-specific article from mid-2018 goes into specific detail about 
calibrating iMacs:
https://photographylife.com/how-to-calibrate-imac-and-imac-pro-displays

I am typing this email on an iMac Retina 5K (known in Apple 
documentation as "iMac18,3") that I have calibrated with the i1Display 
Pro device using the software recommended by that author. I don't 
reverify the calibration often enough, but I know I should. I also know 
I should floss my teeth twice a day.

There are certain people on the LUG whose online pictures always look 
off to me. Off-color, off-contrast, off-gamma, whatever. I don't take 
this as evidence that they are bad photographers, I take this as 
evidence that they used an uncalibrated monitor to fine-tune their 
images, and that what they saw on their screen is not what I'm seeing on 
mine. If I could adjust my iMac so that its display matched the display 
of photographer X, I suspect that what I saw would look better. But I 
can't do that. The only choices are to live with wrong colors or to get 
everybody to use calibrated displays and managed colors.

Even black and white images are vulnerable to mis-calibration 
distortion. The luminosity transfer function (which determines the shade 
of gray displayed for a given luminosity value in the image file) can be 
all over the map. Sometimes I see a monochrome image on the LUG that I 
like so much that I try to reconstruct the profile that the photographer 
must have been using so that I can see the same shades of gray the 
photographer does. It's too complex to try to do that with color images.