Durable, dependent, efficient, and cheap ColorChecker for long-term outdoor use

cmcninch · Feb 11, 2016

I'm looking and researching for a ColorChecker system Colorchecker Classic - Camera & Image Calibration: X-Rite Photo & Video able to withstand rain, sun, wind, etc for long periods of time but still able to give reliable color balance characteristics in an outdoor setting for up to two months.

I plan on doing time-lapse imaging of plants with several different Nikon Coolpix 3700s cameras and was hoping to calibrate the white balance from camera to camera for different shading/lighting effects if possible.

I understand that the integrity of the color standards fades with UV light, moisture, etc but was hoping to have a system able to withstand these types of elements. I am willing to sacrifice a little on the exactness of the color standards if we can have lots of durability.

Current thoughts are:

laminating color checkers (but run the risk of glare issues from reflectance)

using underwater Colorcheckers, I guess amphibico may have one according to this forum thread, Underwater ColorChecker/Macbeth Chart? - Techniques and Tips but the link to their site isn't working

or only taking a few ColorChecker photos.

Thanks for your help!

Ysarex · Feb 11, 2016

A colorchecker has no use or value if you're using a Coolpix 3700. Normally you would use a colorchecker to build a custom input profile for a camera. That input profile would then be used when converting the camera's raw file to RGB. The Coopix 3700 completes that raw to RGB conversion step in the camera and delivers a processed JPEG. Once that's been done you can't undo it and redo it and you can't do it again if it's already been done.

You can, as you suggested, set a custom white balance on a Coolpix 3700, but not with a colorchecker. You'll need a larger WB target for that. You could use one of these: WhiBal - LensAlign which should be durable enough for you or you could use one of these:

which should also be pretty durable, work as well or better and be less expensive.

Joe

cmcninch · Feb 11, 2016

Joe,

Thanks very much for your quick response. I see what you mean by being unable to build a custom input profile for the Coolpix 3700. Can you, however, clarify this for me:
1) For any one camera, if I have the color-checker in every single picture being captured, then can I do a post-processing using any software (e.g. I saw a routine available in Matlab) to ensure that the each image obtained from that very camera is balanced to the reference color checker? My specific interest is not to be able to obtain the exact color as the eye perceives it, but rather to be able to track the change in greenness (hue) of the plant over time with respect to the first picture taken of the plant.
2) For doing something like this outdoors, where the lighting keeps changing with clouds etc, is it sufficient to use white balance or do I need a color checker for tracking the change in hue?

Best,
Colton

Ysarex · Feb 11, 2016

cmcninch said:
Joe,

Thanks very much for your quick response. I see what you mean by being unable to build a custom input profile for the Coolpix 3700. Can you, however, clarify this for me:
1) For any one camera, if I have the color-checker in every single picture being captured, then can I do a post-processing using any software (e.g. I saw a routine available in Matlab) to ensure that the each image obtained from that very camera is balanced to the reference color checker? My specific interest is not to be able to obtain the exact color as the eye perceives it, but rather to be able to track the change in greenness (hue) of the plant over time with respect to the first picture taken of the plant.
2) For doing something like this outdoors, where the lighting keeps changing with clouds etc, is it sufficient to use white balance or do I need a color checker for tracking the change in hue?

Best,
Colton

It should probably be sufficient to make sure you set a white balance. Regardless of what you've seen, the colorchecker in each shot will not permit you to adjust or balance the photo to

cmcninch said:
Joe,

Thanks very much for your quick response. I see what you mean by being unable to build a custom input profile for the Coolpix 3700. Can you, however, clarify this for me:
1) For any one camera, if I have the color-checker in every single picture being captured, then can I do a post-processing using any software (e.g. I saw a routine available in Matlab) to ensure that the each image obtained from that very camera is balanced to the reference color checker? My specific interest is not to be able to obtain the exact color as the eye perceives it, but rather to be able to track the change in greenness (hue) of the plant over time with respect to the first picture taken of the plant.
2) For doing something like this outdoors, where the lighting keeps changing with clouds etc, is it sufficient to use white balance or do I need a color checker for tracking the change in hue?

Best,
Colton

Setting a white balance should be sufficient. You're not exactly working with a precision tool here. If there's a colorchecker in the shot the Coolpix will apply it's internal input profile when it creates the RGB photo -- that's going to render the colorchecker inaccurately -- white balance or no white balance. No adjustment after the fact is going to fix that.

But you're interested in change more than accuracy. So what I'd do is include a single color reference that's close to the color your concerned with. Foliage is yellow/green so I'd get a yellow/green object (durable) and make sure that's in each photo. I'd still do the white balance. Then I'd check that reference object for frame to frame consistency.

Joe