I have two different cameras, each shoots raw from the company's own algorithm. I'd like to calibrate (ICC) both cameras, so they'll print with a more standard color base.
Is the 24 colorchecker passport too limiting? Or should I collect paint sample swatches as well as different color products to make a test target; profile?
Forget ICC calibration for cameras.
There are currently three different "camera color calibration" systems.
1) Adobe DNG Profile editor (free @ https://www.adobe.com/cfusion/entitlement/index.cfm?e=labs_dngprofileeditor
2) X-rite Color Checker Passport. http://xritephoto.com/ph_product_overview.aspx?id=1257
The software alone is still free (go to http://xritephoto.com/ph_product_overview.aspx?id=1257
>Support> Downloads) but you can also buy the ColorChecker passport target set.
Options one and two require an X-rite 24 patch Color Checker target. A small version of the 24 patch is in the ColorChecker Passport target set which also includes a biasing target for both landscape and portrait work and a large white balance target, all in a pocketable hard plastic shell.
Both require you to shoot the target in raw mode, open it in either Adobe Camera Raw or Lightroom, export the photo as a DNG and use the respective software to build a "Camera Calibration" profile which you name and install. You then quit ACR or Lightroom and when you restart either the profile should appear in the Camera Calibration menu. In Lightroom you can create a preset for applying the profile during import.
An option with both the Adobe and X-Rite CCPP software is the ability to build a dual illuminant (flash/daylight and 3200˚K)profile which works well when working in mixed light conditions. This requires shoot the target under both types of illumination.
In Lightroom (at least you can apply the profile to proprietary raw formats, DNG raw format (if you use that) or JPEGs,
3) The Datacolor Spyder ColorCHECKR - target and software. Instead of using the Camera Calibration settings you build an H/S/L profile for use in Lightroom or Adobe Camera Raw.
I have used all three. All three do a fine job, but it is like ordering vanilla cream from three different creameries - there are variations between the two. When tuning a new camera these days I will build profiles at least two ways (usually Xrite CCPP and Datacolor ColorCHECKR) and see which works best. The important thing is for you to decide which calibration system you want to use for the cameras you want to co-ordinate color with.
Keep in mind that different camera makers have their own built in bias and I do not think it wise to expect o get completely identical color out of a mixed brand set of cameras. a close to very close match but not an exact match, and that may even be true of different generation cameras of the same brand (examples : a Canon EOS 1D mark III and a 1D X or a Nikon D3x and D800)
What exactly are you photographing? What type of lighting and how varied is the lighting from session to session?