Quote Originally Posted by vdonti
On these color cards, help me out - never used them although I have a darkroom with twin D5XL enlargers and a 31" Kreonite processor on color.
Are you adding these color patches in one of your photographs and then adjusing your enlarger color Pack so the colors match? Just wondering if I need to get these?
I kind of "jumped in" and discussed one particular aspect ... that there are ways to control contrast, color balances ...

I use a ColorStar 3000 analyzer ... you may hear more about this machine on APUG in the future.

With this, I usually include the image of a gray card in one of the frames under a particular light. Gray consists of yellow, magenta, cyan (or, if you prefer, Red Blue and Green) and ~ 18% density.
From this gray card image, I'll make test strips, so that the analyzer, when calibrated (it has an internal calibration system) will duplicate that gray in the print.

It is entirely possible to calibrate this machine from a different color - I have a channel set up for "Fair Caucasian Skin" - or green grass, or blue sky..

It is not an infallible solution to all color balancing problems - the esthetic judgement takes precedence over the absolute values - but it is an *immense* help.

I know I've saved far more than the cost of this machine in materials, time, and frustration.

The MacBeth "Color Checker" cards are useful in comparing color balances between various films.... one can get an idea of the "strengths" and saturation of different colors -- "standardized" as "green grass", etc.
These puppies are realtively expensive - of late something like $70. The one I had was lost in the "great flood" that hit here a few years ago (12" of rain in 12 hours - my darkroom had three feet of water in it) and I haven't replaced it. I really don't miss it much.