Damn you, Dynamic Contrast!

Today I was calibrating a Samsung monitor for a lovely lady here in Brisbane. I ran the calibration/profiling, and was immensely satisfied with the result graphs that the i1 provides at the end of the process. Thinking all was well, we proceeded with some Photoshop work.

I was appalled to see the first black-and-white image that we opened – it looked strangely pink! And the next one was, too. And some colour images had a less-than-perfect hue to them as well.

It was obviously a profile problem, not a calibration problem. The screen looked fine, the neutral-coloured palettes and background in Photoshop were grey just like they should be, and other software looked great as well. Only the photos themselves were screwy. Clearly there was some wacky colour-management going on.

So, I ran the calibration again. My trusty i1 wouldn’t throw a dodgy profile twice in a row, surely?

No good. Still pink. I tried again with different calibration targets – same problem.

On the third or fourth attempt, I noticed that the calibration progress window was behaving strangely – at various points it would fade, then become bright again. I’d never seen this before, but it gave me a suspicion.

Sure enough, I had a look at the Samsung label on the monitor, which proudly proclaimed:

"20,000:1 Dynamic Contrast Ratio"

You scoundrel! I’d occasionally read about this problem, but never encountered it before.

Wikipedia says:

Dynamic Contrast Ratio: A notable recent development in the LCD technology is the so-called "dynamic contrast" (DC). When there is a need to display a dark image, the display would underpower the backlight lamp , but will proportionately amplify the transmission through the LCD panel. This gives the benefit of realizing the potential static contrast ratio of the LCD panel in dark scenes when the image is watched in a dark room. The drawback is that if a dark scene does contain small areas of superbright light, image quality may be over exposed.

Damienpedia says:

Dynamic Contrast Ratio: An annoying function that is great for movie-watchers, but terrible for photographers!

What was happening, it seems, is that when the i1 was reading dark colours to make the profile, the brightness of the screen was automatically adjusting to make those colours "better" (yeah, right!). And this was screwing with my profile!

Once I figured out how to turn off the Dynamic Contrast function in the monitor’s settings, it calibrated like a dream, and the photos looked fantastic!

You learn something new every day, right?


If you have a question about this article, please feel free to post it in Ask Damien.