Hi, I'm kinda new to this digital photography thing. I've been editing my photos on a PowerBook G4 15" using Photoshop CS (1) for several months now. Then I bought an external Acer AL 1751 & decided that colour calibration would be a good thing. So, I've now done that using a Spyder 2 device.
However, reading through various web pages & forums, it seems that recommendations are that I should set my monitor gamma to 2.2, whereas it was 1.8 previously. Having done that, everything looks dark, which I gather is how it's supposed to?
Now, do I have to go over all my photos that I've previously processed & remanipulate them now that I have a gamma of 2.2? What are the implications for viewing photos on Windows monitors (with a gamma of 2.2) or printing in photo shops (gamma of 1.8?)? Should I have the Mac gamma at 1.8 or 2.2 to have Windows users view my photos properly?
If I use a gamma of 2.2, does the Mac interface (Aqua) looks darker than it should? (It certainly seems that way.)
(I've also posted this question on another photo website, so apologies if anyone here frequents both places & recognises the post.)
You need to re-do your calibration with the new gamma. You're right, it'll look a little darker and contrastier. Then, do some prints with your normal printing processes to see whether the 2.2 gamma works well for you. The 1.8 suggestion worked well with older B/W laserprinters, and was supposed to match commercial printing better also. Thus, people who used Macs for graphic design set their monitors at 1.8 gamma. Granted, I think that 1.8 shows a little more shadow detail on screen than 2.2, but I find that prints from my Canon match better when I set my gamma at 2.1 actually, so that's where I put it during the calibration process (with a G-M eyeOne). The 2.1 setting is close enough to the "Windows uncalibrated default" of 2.2 that my web images look good. You may have to experiment to find the optimal gamma setting for your system.
You wouldn't necessarily have to go back and reprocess piuctures, but realize that your web images look darker to someone on an average Windows system, and many people on Macs too who have set to 2.2 gamma.
I find that 1.8 is the best setting for soft-proofing before most CMYK output methods. I just keep mine at 1.8 all the time as it is still considered appropriate for pre-press standards and most of my clients need it that way.
"Windows uncalibrated default" is the native gamma of the display (ranges between 2 - 2.5). The gamma is a physical property of the device. Mac gamma of 1.8 is due to OS adjustment.
Assumming photos have had proper embedded profiles: If you are viewing the photos in a colormanaged app such as Photoshop, the gamma you calibrate your monitor makes no difference at all. You could calibrate to 1.2 or 2.8 for that matter, and the photos viewed will look the same level of brightness and contrast. The difference will be in the quality that the monitor displays the images. Most modern LCDs are designed to render best at 2.2, and the further one's gamma deviates from that optimum, the more you risk introducing banding, artifacts, or other defects into the image your monitor is rendering. I run mine at 1.8 and images render the same as 2.2.
If you are viewing non-colormanaged apps like Preview, web browsers, etc, and you calibrate your monitor to a gamma higher that your what OS runs at, things will appear a bit darker, and conversely, if you calibrate your monitor to a gamma lower than what your OS runs at, things will appear lighter.
Thanks for all the replies. I'm getting more & more confused. It seems to me that the monitor, as a hardware unit, has a built-in gamme unit associated with it. Additionally, there seems to be a system-wide software gamma setting. Is this right or wrong?
I always thought that the process of calibrating a monitor/system was to ensure that when my computer says to display a, say, green pixel, the same shade of green would show on my monitor as on, say, my friend's monitor, my brother's TV, etc. Whites should be pure whites, untainted by colour casts, etc. Now that there are settings for temperature/Kelvins, & gammas, it seems that my theory was incorrect. Is this so?
Gamma is a complicated subject as such, AND because the term is being used to describe different things (CRT transfer function, gamma correction/encoding, gamma in image editing applications).
I suggest the folowwing books:
"Real World Colormanagement" by Bruce Frase, et al. It has been the industry standard for many years, and written in plain simple english.
"Color Management for Photographers" by Andrew Rodney is newer and just as highly regarded.
> "Real World Colormanagement" by Bruce Frase, et al. It has been the industry standard for many years, and written in plain simple english.
"Color Management for Photographers" by Andrew Rodney is newer and just as highly regarded.
These books are very good indeed and I would certainly suggest these + Abhay Sharma's "Understanding Color Management" to anyone interested in color management, but you won't find a lot of info on gamma in both (by far not to the extend that Poynton describes it).
