And while I'm at it... Camera calibration scripts

I finally got around to reading the Lightroom 2 book b Martin Evening and came across an interesting factoid on page 310 which may explain why ACR misses the mark compared with NX.

"Over 175 different cameras are supported by Adobe Camera Raw (ACR) and Lightroom, and in some instances several camera samples were tested to obtain a representative average set of measurements. Other times only one camera model was actually used.... However, the sensors in some cameras can vary a lot in color response from camera to camera, and this variance means that although a raw file from your camera may be supported by Lightroom, there is no guarantee it will be exactly similar in color response to the raw files from the camera."

Mr. Evening has referenced a link to Thomas Fors' ACR Calibrator script which works in MAC & PC's for anyone who is interested.

http://fors.net/chromoholics

The script requires the use of an X-Rite Gretag Macbeth color checker chart and Photoshop CS 2-4.

I highly recommend " The Adobe Photoshop Lightroom 2 Book" by Martin Evening (Adobe press - Peachpit), especially now that I have freely and without permission referenced his work.

Also, for those interested, Adobe has had a camera profile and DNG editor beta available on their website since October.

http://labs.adobe.com/wiki/index.php/DNG_Profiles

I prefer Tindamans' ACR Calibrator L although I've modified it to use the ColorChecker values that match Imatest. Rags Gardner offers a good site for ACR color calibration as well. All these techniques are superceded by the new ACR profile generator.

The problem with all these old scripts is that they don't have control over individual color patches, so you have to manually adjust individual colors and rerun the scripts repeatedly for best results. You really need something like Imatest as well and that's expensive. Transferring the results into Lightroom is nonintuitive also. I would set aside a half day to do this for each calibration I wanted. The new method is essentially instantaneous and delivers superior results plus LR can use them directly.

Excellent! You just saved me a whole bunch of wasted time. Thanks.

Do you find that using the ACR profile generator makes a big difference from the "boxed" version?

Profiles you make with the generator are fundamentally different from the boxed versions. The default profiles do not produce accurate color, they produce colors that hopefully people will find pleasing. Their color output varies with brightness as well. When you make a profile yourself with a ColorChecker, you should end up with a profile that is reasonably accurate. Whether that produces a "better" result is a matter of taste. If you are doing HDR work, you would want as accurate a conversion as you can get and should not use the canned profiles. That's my understanding, anyway.

Man, I was hoping you wouldn't say that! Thanks. Does the Gretag Macbeth work best?

I believe the ColorChecker chart is the only one the DNG profile editor supports. It works fine.

I believe the ColorChecker chart is the only one the DNG profile editor supports. It works fine.

Thanks.

Do you find that using the ACR profile generator makes a big difference from the "boxed" version?

I used the Adobe software and a Colorchecker lit by the Z240's out of the water to generate new profiles for both cameras. After applying the new profiles in Lightroom orange/red now look spot on. I can see virtually no difference colourwise between photos processed using Lightroom with the colour profile I generated and photos processed using Canon's Digital Photo Professional software (widely recognised as having the most accurate colour results).

Yes. I was never happy with the orange/red coming out of my wife's 400D and my 40D when used with Inon Z240's for macro work, they were just too saturated for my liking.

The new Adobe standard profiles address the orange/red issues already. That was the reason I profiled before but it's unneeded now.

I used the Adobe software and a Colorchecker lit by the Z240's out of the water to generate new profiles for both cameras. After applying the new profiles in Lightroom orange/red now look spot on. I can see virtually no difference colourwise between photos processed using Lightroom with the colour profile I generated and photos processed using Canon's Digital Photo Professional software (widely recognised as having the most accurate colour results).

I don't agree that Canon's DPP software is widely recognized as most accurate. Neither is Nikon's software. Both are widely admired for their color output but neither company intends their color to be "accurate". If DPP results are what you desire, you are better off with the new Adobe standard profiles since that is specifically what they are created to emulate. There are specific reasons why that is so and there's good reading on that subject in the Adobe forums. A well made custom profile for your camera will be more "accurate" than DPP will ever be.

Eric demonstrated recently that DPP still does a better job with sunballs that ACR even with the new profiles. Don't know how it compares to ACR with a custom profile but highlight recovery is an area where converters are different and that has significant meaning to our shooting.

I went out and got my x-rite colorchecker and ran the DNG profiller. Definitely affected the blues in my images from the D3.

Thanks.