Calibrating and profiling Digital Cameras

[donbga]

I curious about how to go about calibrating and profiling my Canon 400D camera.

Is anyone here doing this and if so how?

Thanks,

Don Bryant

 

[wiz]

There are a number of ways to profile a camera. I usually do the simple thing, I shoot a Gretag Macbeth Color-Checker and use a Tom Fors or Rags Gardner PhotoShop action to lock the color in on ACR.

Tom Fors

Rags Gardner

I don't normally play with the programs that try to derive ICC profiles from cameras.

 

[donbga]

There are a number of ways to profile a camera. I usually do the simple thing, I shoot a Gretag Macbeth Color-Checker and use a Tom Fors or Rags Gardner PhotoShop action to lock the color in on ACR.

Tom Fors

Rags Gardner

I don't normally play with the programs that try to derive ICC profiles from cameras.

Thanks wiz,

Those are the two sites I've reviewed so I'll give them a go. Happily for me I do have a MacBeth Color Checker.

Don

 

[Baxter Bradford]

Really helpful links Wiz - thankyou.

I've just bought the GM 24 patch Colour Checker card and am about to get cracking making the profiles.

Would be grateful if anyone could say if I need to do the profiling with each lens and range of conditions? I was intending to use Expodisc to set white balance and exposure accurately.

Many thanks

 

[Greg_E]

Yes each lens, each set up, each lighting change, etc. It's kind of a moving target with camera capture because the conditions can change so much from shot to shot. You may be able to get close if you do one for each lens and each type of lighting, but to really get the types of results that some people are looking for you need to almost have the chart in each shot. The bigger the chart (more patches) the more relevent this becomes. The 24 patch is a pretty wide correction and will probably give you good results over a wider range of conditions.

 

[Baxter Bradford]

Thanks Greg

I've pressed ahead and made several profiles for different lighting conditions, but not for each lens. I used the Tom Fors process/script.

Initial results to my way of seeing are that the greens are overly saturated. I'm currently tinkering, but they are worthwhile generating for your camera.

Warning - each seems to take about an hour to produce.

 

[Greg_E]

The green in the Macbeth chart is a little weak if I recall, this might be throwing the profiles off depending on the reference file. Also is your monitor calibrated? Are the neutrals coming out OK?

 

[Baxter Bradford]

Thanks Greg,

Yes, my monitor is calibrated and neutrals are fine. The greens are more intense than Velvia 50. There is no option t o inspect or amend reference file. The set-up is done by iteration, hence the long build times.

 

[donbga]

Thanks Greg,

Yes, my monitor is calibrated and neutrals are fine. The greens are more intense than Velvia 50. There is no option t o inspect or amend reference file. The set-up is done by iteration, hence the long build times.

So after you load your profile in the RAW processor you can see the over saturated greens?

Thanks,

Don Bryant

 

[Baxter Bradford]

Hi Don

Yes something like that! These are not genuine ICC profiles which are produced which you then assign in a colour managed workflow. Other profiling systems can produce them, but ICC is not currently useable with Lightroom. Such software systems aren't free either!

I import RAW file into Lightroom with no develop settings. The Numbers generated by the profiling procedure are the adjustment settings in the camera calibration panel - these are saved as a Develop preset. If using Adobe Camera Raw then have saved same numbers as a setting.

The green saturation figure is 53 in overcast conditions and I've found that reducing to 14 makes it look better to my eyes. I've not had time to look at the 'profiles' for other lighting conditions.

Sorry not to be able to add more substance - very much work in progress, whenever I can get time to evaluate. I'd never have come up with such bold input figures to get to the datum.

eg my figures for Leica M8 (with IR cut filter in place)

Overcast lighting
Shadow Tint 0
Red Hue -4 Saturation +13
Green Hue 0 SAturation 14 (was 53)
Blue Hue 21 Saturation -12

Full early afternoon sunlight
Shadow Tint 0
Red Hue 0 Saturation +8
Green Hue +7 Saturation +34 (needs reducing I think)
Blue Hue +22 Saturation -10

Main thing is that the procedure works well, but you don't have to accept the 'off the shelf' version of 'true' colour.

 

[Greg_E]

OK, now I understand a little better. You are making developer files.... These were done in software converters years ago, like with the 6 MP Fuji Luma backs. It sounds like the Lightroom routine is doing something funny in the conversion.