The fact monitors aren\'t calibrated isn\'t as big a factor as you might think. TVs are not calibrated either and that doesn\'t create a problem.
When sitting in front of a monitor your brain adapts color and contrast perception to that gamut. If the screen is uncalibrated and has a slight green cast your brain expecting the content is sees on the screen to be neutral shifts perception of the screen gamut to make the stuff it sees on it neutral. it\'s only when the error is gross or the ambient lighting is significantly different in white point that a calibration error will be noticed.
There is a standard on the web. As mentioned back in the 80s before the Internet Macs were 5000°K and 1.8 gamma to simulate a printed sheet of paper. MicroSloth took a different approach and standardized on the physical characteristics of a CRT gamut resulting in huge difference in appearance of files edited on Macs and PC when people started sharing them over the net in the mid-90s on web pages.
Since PCs outnumbered Macs the de fault standard became sRGB which is more similar to the native CRT gamut than Apple\'s \"paper white\" perceptual match approach was. The result?
Now everyone sees similar color on their screen if the images are converted to sRBG but the Catch - 2.2 of the de facto sRGB standard is the 2.2 gamma that is part of the sRGB and other RGB monitor standards doesn\'t match the lower contrast of a print; what Apple was trying to do by using the lower 1.8 Gamma on the screen.
Why didn\'t 1.8 gamma become the standard? Because while it match the contrast ink on a printed page it doesn\'t look normal on a monitor. That\'s the crux of the screen vs. print match problem. Ink on paper has lower contrast than the 2.2 calibration standard of the monitor. You can change the gamma of the screen to match the ink and paper (what soft proofing does) but you can\'t increase the contrast of the print. All you can do is shift the mid tone which affects how what is between black and white is perceived on the print.
On overcast days there is the opposite problem. The contrast of the lighting is so low that the camera sensor records the midtones and shadows lighter than perceived by eye and the resulting image looks \"flat\"..
The remedy? To \"normalize\" the contrast in the lower image I shifted the midtones .15 to the right:
That\'s opposite of the correction I\'d make in a sunny scene where the exposure set for highlight detail would render the midtones darker by eye. For a sunny scene I\'ll adjust brightness and fill in the RAW file which has the same net effect on the mid-tones in RAW as the middle slider movement in Levels: making the overall tonal range the camera was able to capture more closely match my impression by eye.
Unless one has an understanding of reproduction variables it\'s not easy to look at an image and determine whether the overall difference in appearance perceptually is caused by color variance (gamut mis-match) or a difference in contrast. The brain adapts perception of both to the overall contrast range of whatever is being looked at (print or screen) individually and when both are seen at the same time the one with greater contrast is used for comparison.
That problem is exacerbated with outdoor digital captures because SOOC the a file exposed for highlight detail has a loss of shadow detail and darker than seen by eye midtones. That\'s a contrast problem. The photographer lowers contrast so it looks good on screen but then when printed it gains contrast again perceptually due to the mechanical variables of printing a screen image doesn\'t have: overlapping stochastic dot pattens and ink spread/absorption. Ink printers have different mechanical variables than laser printers which fuse toner to the paper or photo printers which similarly expose the paper with laser LEDs.
Jul 30, 2012 at 09:52 AM
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