Adjusting image brightness for projection...

Like many of you, I gauge my images' brightness based on what my pp is telling me, and what I see on my monitor. I've learned that for some images, when printing them, that a boost of say 10% brightness seems to suit the paper form of the image. For club functions, where images are most commonly projected, I think I need to do the reverse of printing, that is, scale-down the brightness to compensate for that means of presentation. If it means anything to you who are familiar with such devices, the club's digital projector has a native XGA resolution (1024 pixels x 768 pixels) and 2000 lumen brightness.

Because there is no trial and error method for me here, unless I went out and bought a projector for myself, is there a general rule to be applied for adjusting brightness for when images are being projected? Any difference for b&w versus color?

Thanks for your comments.

What about doing a color calibration on the projector?

I believe what's most critical here is the viewing environment.

Hi Kevan, I do volunteer competition judging for the Cleveland Photographic Societyseveral times a year and we confront similar issues. I would recommend that you make the best possible "print" you can, and NOT adjust it for projection judging.

At CPS the judges score an actual print that we see away from the audience, in a separate viewing room. The matted prints are placed on an easel and illuminated by spot light, and the judges sit at a comfortable viewing distance (about 6') and score them accordingly. When the scoring is done we return to the audience/viewing room where the images are projected. Each photo is then projected for our narrative critique.

The photographers are asked to submit files that are 1024 pixels on the longest dimension, about 1mb in size. The club tries to set the illumination level for best possible viewing and most of the time this is achieved. I really think you need to create the best possible print/image you can, on your own calibrated monitor. I can't say there are any general rules Kevan - or maybe I'm just not aware of them. We can talk about it some more though if you have specific questions and I'll try to help as best I can. - Stu

You'd be better off showing a screen calibration image on the monitor and adjusting the monitor for proper brightness and contrast showing the brightest white and darkest black of a grey scale bar. But typically projectors are not as bright as screens and don't have the ability to display a wide range of light, so the projected image ends up looking a bit dark if you want to see every range of light in the image. You can crank up the projector contrast but you'll have very dark black and blown highlights to deal with.

Thanks guys, for the comments and suggestions. I had projected this one particular b&w image and all my burning efforts were quite evident. I was a bit embarrassed, I'll admit.