Calibration - does iMac have Brightness or Backlight?

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Calibration - does iMac have Brightness or Backlight?

I have been calibrating my 20" Intel iMac display with a Spyder2 colorimeter. However, all my photo prints run dark which should mean my display is too bright. In trying to adjust calibrated brightness (luminance) I've run across some questions.

First, does the iMac have a "Brightness" control or is it really a "Backlight" control? The Spyder help material says Apples brightness is actually backlight. True or False?

Second, does the iMac actually have a Contrast control? Since the contrast slider is located in Universal Access rather than Display it makes me wonder if it is a true contrast control or setting some other parameter.

I need to know these answers in order to properly configure the Spyder software.

The version of the Spyder I have does not allow mechanical luminance measurement. I am thinking of upgrading to a newer model with a higher level of the software so I can actually measure luminance in an effort to achieve a known value less than 120.

Before acquiring the iMac I had a successfully color managed workflow using a Windows PC and CRT. Since getting the iMac with a built-in LCD display I have torn out my remaining hair trying to get back to that state of affairs. Why is the iMac so bloody difficult to color manage?

iMac Intel 20", Mac OS X (10.5.5)

Posted on Nov 8, 2008 9:15 AM

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Answer 1

Nov 12, 2008 5:38 PM in response to larry_photog

Have you tried to use the ColorSync app thats built into OS X? It should be located in the Utilities folder (Macintosh HD/Applications/Utilities). Thats exactly what that app is supposed to do.

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Answer 2

petespot

Level 1

15 points

Nov 12, 2008 10:09 PM in response to larry_photog

Hi Larry- You will NOT be able to deal with contrast on this monitor and you will NOT be able to get the luminance below 120 so DO NOT buy the more expensive Spyder as it will not help. In your old CRT (depending on the model) you had the ability to change contrast and even change the color Bias etal one gun at a time, no so with the iMac screen. The screen is natively too bright and lowering the brightness to minimum makes the contrast too low for the type of calibration you are looking for. There are software fixes like Shades etc that will allow lower brightness below the built in parameters, but then your whites will be gray. If you want that type of precise calibration you need to buy a second higher end monitor and use that for your image screen.

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Answer 3

Nov 16, 2008 11:27 AM in response to petespot

Larry / Petespot

yep so true, i got a new imac24 for doing review work last week, thought it wouldf ill the spot . all my other machines are mac pro with lacie or eizo panels that calibrate just fine.

out the box the screen is better as a floodlight than a monitor! ive played around a bit and using my old spyder ( blue eye pro just could get a decent reading) and turning down brightnessfull managed to get the lum down to around 160, but now the screen has a nice left/ right gradient across it maybe 15% darker on the right, reading the forums seems to be the norm.

guess it will need to be used as a machine for playing movies, !! pity as its such a nice piece of work

but you get what you pay for, in the UK £1100 for a 24" imac, my lacie monitor is that and some so you cant expect the same level of panel continuity not even with the buying power of apple.

any thoughts

andy

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