Thursday, April 30, 2009

Gamma Settings: Using Image Ready to Adjust for Best Cross Platform Effect

See the post on Gamma on my painting blog for more information and a disclaimer.

Have you ever looked at your blog or website on a computer other than your own? You might be in for quite a surprise. It's probably NOT going to look the same on another computer as it does on the one you have at home (or office). Especially try and get a look on the platform you don't have-- such as view your blog on a Mac if you own a PC, or on a laptop or flat screen if you're using a CRT old style monitor. Because we edit mostly on one given computer, that is the one that is 'True' to our eyes. But it's a partial truth, at best.

"The gamma value of a computer monitor affects how light or dark an image looks in a web browser. Because Windows systems use a gamma of 2.2, images look darker on Windows than on Mac OS systems, which are normally set to a gamma of 1.8."

  • So if you're viewing other peoples blogs and websites from a Mac, it might seem that a lot of other people's images are washed out looking.
  • Conversely, if viewing from a PC, there might be some other's images that are so dark you can barely make them out.

Well, we can't do anything for most of these images, but we can be aware of the impact of our own images. Luckily there's a pretty simple way to make this adjustment. First, a visual example of what we're talking about:

Gamma 1.8 example (as might be created on a Mac, but as seen on a PC)

The same image, but as a Gamma 2.2 example (as might be created on a PC, but as viewed on a Mac)

You might be thinking, why should I care? And maybe you don't need to. I do think most of want our images show up as true to life as possible; however given the millions of monitor variations (and the fact that almost no one calibrates their monitors the suggested once a month), I'd only be concerned if I was consistently getting messages from others that my images were showing up too dark or too light. Mac users won't like this one bit, but because of the predominance of PC's, Mac users might be the ones to find this information most helpful.

To adjust your gamma settings, you'll need to open your image in Image Ready (this comes bundled with Photoshop); one way, if you were making edits in Photoshop, is to click on your 'File/Save for web' option; the dialog box that opens witll have an option at the lower right corner: "Edit in Image Ready".

From there, choose Image/Adjustments/Gamma as shown below.

The gamma dialog box will pop up and offer 2 basic buttons: click the one appropriate to your situation (example: choose Windows to Mac if you to email a photo to a client who has a Mac, but you have a PC). The image will automatically adjuct; then you just need to save it.

A possible workaround to this issue is the PNG file, but..."The PNG graphic file format has a feature that effectively adjusts the gamma of picture depending the platform it is running on. It sounds like an ideal answer but the format has been very slow to take off and is not widely supported by browsers." (Click for source)

As an experiment, I'm posting PNG file here. Let me know if it appears on your screen, and whether it looks 'more acurate' than either of the two above.

Was any of this helpful? Let me know.


  1. Thanks for the was very helpful!

  2. Hi - it looks (on my monitor) like a happy compromise between the first two versions. I'm still a bit confused (my normal state, and not your good explanation). The gamma 2.2 pic looks best on my mac monitor. 1st one looks very dark. Does this mean that most of my work online looks pretty grim to my PC friends?

  3. The PNG file is definitely coming out best for me, as it lets me see the details in the darker areas without washing the rest out. Hopefully that format will continue to gain ground.

  4. Thanks, Dana... I tried to narrow down what seems a large topic... news to me!

    Hi Liz, Actually the images on your blog look pretty good for the most part; I had checked with a few people with dark images, some had Macs, but some did not. 'Angel' is a bit dark on my PC, but 'Trixie' has wonderful brightness and contrast.

    Hi Kerri, I wish I could track when the PNG reference I found was written; maybe it's safe to use in most formats already. I'll do some more research and see what I find.

  5. The final image there does look like a "happy medium" to me on my monitor. I'm on a Mac, so I'm guessing mine are looking very dark to people on PCs?! (Is that what Liz just asked you?)

  6. P.S. And, hate to say it but I often think others' images look "overexposed" in a way... Is this why??

  7. It is hard to pick among the pictures as it is subjective since I do not know what the original looks like. I personally like the 2.2 but is it a true representation of the photo? That being said, thank you very much for the info as I wondered why that happened and it is good to know. Thanks Honor

  8. I just had my Photoshop as present (and what a present!) So, I've learned how to open an img file (double click ;) and how to save it, easy...yea!

    Have you been helpful??? Of course you have! I jumped 1345 steps but I know I have a chanche to gamma-correct my paintings img!

    I'm sure I must go to read past tips, anyway THANK-YOU!

  9. Wow This is so beyond me. Interesting, may need this information. I do not use photoshop (would like to some day). I did not see you address a factor that I have been concerned with about the appearance of my art on my blog. Does an individual's blog template colors, you know, the one chosen that surrounds and backdrops all their postings, have a huge affect on the way a monitor promotes the art image? Can us simple art bloggers compensate for ills in gamma by just choosing better backdrop colors? I used to have a light background, but now I chose darker.

  10. Hi Jala,
    Yes, I think you're right on both counts. This is why I guessed that you were working from a Mac. I'm glad to hear the PNG seems like a happy medium... I think I'll start posting mine that way, and maybe you can let me know if they seem less over exposed.

    Hi Honor,
    You're right; there is a lot of subjectivity built in. Out of the 3 examples shown, the PNG seems to be the closest (from my monitor) to the original.

    Happy to be of help!

    Hi Sandra,
    I'm guessing here, but no, I don't think your template colors ‘physically’ effect the monitors interpretation of the colors of your images, although having a dark background does ‘visually’ set them off more to the human eye... I like your darker template, and your colors look very brilliant and saturated. On my monitor, your images have some of the best color and contrast of any blog I've seen.

  11. PNG appears between the two -- but I prefer the Gamma 2.2 look. Jala Pfaff's did indeed look very dark on my PC.

  12. I agree with Charlene. I'm on a PC and the PNG is a compromise between 1.8 and 2.2. I like the 2.2 best, but perhaps that's because I also live in (at the moment) sun-starved Denver.

    Just visited your food and garden blogs, R. You are so multi-talented!

    Jala's images are also dark on my PC.

  13. Hasn't this weather been THE WORST?

    Now I'm paranoid that all my images look dark to everyone! :O Oooooh noooooo Mr. Bill! I will try to remember to look at my blog on my friend's PC.

    Your own images never have looked "overexposed" on my monitor, but others' have.

  14. Great information....who knew??? From a Mac user!

  15. Charlene, Cheryl, Jala, and Ann; thanks for weighing in.

    and yes, I'm More than ready for some warm weather!!

  16. Your png file looked like a good compromise, but I don't know if its going to be used much.
    The down side of this is sending images to a gallery that uses a MAC,the images are then darkened, and finally what I see on my PC does not make me happy.
    Question, whats your opinion on the Spyder for color correcting my monitor?

  17. Cagg, no opinion of the Spyder, as I haven't heard of it. There are many products both free and with cost that may do a fine job. For those outside the 'print' world a free product will usually be close enough.

    The downsides you state are the conundrum; there does not seem to be (at this time) a solution that would satisfy everyone. I write about the subject primarily so that artists can be aware of the various viewing 'realities'.

  18. Thank you - very helpful! This straighten me out re image outcome on the web, and also the value of Image Ready.

    But since I do mostly video, now I need to find the video equivalent of Image Ready...