Thursday, September 11, 2008

Do You See What I See?

While at work today, I entered this image of Union Lane in Melbourne into a competition on RedBubble. I thought I should have a quick look at the full-size image to make sure it was the one I wanted to enter.

When I brought it up, the colours just looked stupid. In particular, the whole left-hand third of the image was a single shade of orange, and not even a nice shade.
It made me think "Why did I even upload this?"

Someone left a comment on the image later in the day, so I opened it up at home to read the comment. And BOY does that shot look so much better at home!

Is it just because I'm not at work and so I'm feeling better about the world?

Is it because I have some awesome $10,000 monitor at home?
No. (Because I don't.)

The reason is simple, but important: Monitor Calibration.

At home, I use an X-Rite i1 Display 2 to calibrate the way my monitor displays colours. It helps me to adjust the brightness, contrast, RGB whitepoint (color temperature) and gamma curve of my CRT monitor so that what I see on the screen is a precise representation of the data in the image. At work (where, I must admit, colour correctness is not a high priority), there is no such calibration of our LCD monitors. The result? Great sadness.


Now, I'm not a professional photographer. Far from it. But if you're going to play around with the colours of your photos at home and then send them to a professional printer, you really, really need to calibrate your monitor. You must. To not do so is just silly. Your editing is quite possibly doing more harm than good.

In fact, even if you just want to appreciate your own and other people's photos properly on your home computer, I highly recommend that you get an affordable monitor calibration device and get your monitor into shape!
My experience at work today showed that an uncorrected monitor can flat-out ruin what is otherwise a lovely image.

Monitor Calibration 101
For the newbies: What happens if you don't calibrate your monitor? Well, imagine there's a piece of plastic between you and your monitor and that this plastic is light yellow, or light blue, or light green. You can still see everything on your monitor, and it appears to have all the colours of the rainbow, but something isn't quite right. This is what an uncalibrated monitor looks like.

In fact, your eyes will slowly adjust to the fact that everything on your monitor seems to have a yellowish or bluish or greenish tone (this is called a "colour cast") and your brain, which is really only interested in what a colour looks like compared to the other colours next to it, will effectively subtract the cast from your vision.

But if, while this piece of plastic is in the way, you start editing the colours of your photos, you will probably make different decisions - wrong decisions - compared to what you would make if it weren't there.

For example, if your monitor has a green cast, you might decide that Aunt May's skin tone is a little green, so you adjust the tone of the photo to represent her typical, pinkish tone. But because your monitor isn't calibrated, the colour you see on the screen - the one you think you've changed Aunt May's skin to - is not actually the colour stored in the image. It is the colour in the image plus the green tone of the cast. It's likely - almost certain - that you overcompensated for the colour cast when you adjusted the colour in the photo. If you were to get this photo printed at the local mini-lab, you would probably find that Aunt May's skin is so red that she looks like she has a third-degree sunburn.

So what does monitor calibration do? How does it work?

When you calibrate your monitor, what you effectively do is let the computer measure the colours that your monitor is displaying. This is done by attaching a calibration device to your monitor and running the software that came with the device. By doing this, the computer can detect the colour cast because it tells the monitor to display white, but then measures that it shows a greenish shade of white.

Once your computer knows the natural colour cast of your monitor, the computer can change the colours that it sends to the monitor to compensate for the cast, so that what you end up seeing is the pure, unadulterated colour from the image.

So, do your Aunt May a favour:

Calibrate Your Monitor Today.

Copyright (c) 2008 Graham Lea. All rights reserved.

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