Color sampling by email & color correction in digital photography


SGF, Supreme Grumble Framer
Dec 16, 2000
North-East US
For future reference I'd like to remind you all two simple tricks:

1. Suppose you got a picture in your email and suspect that its colors are not true. Having a picture in which one spot is known for sure to be white allows for fairly accurate reading / managing of any other color in that picture.
Just open your picture in Photoshop, then go Image>Adjust>Levels. In that last wizard pick the eye dropper from the right (highlights) and, after sampling on your picture's white spot, the image automatically redefines itself accordingly to what was pointed as being white (high light) in that picture. Somewhat related to this topic is the next trick.

2. Most digital cameras today have manual controls and so many bells that only a few really know how to take advantage of. As result most pictures are far from perfect when it comes to color accuracy. The true remedy is called white balance.
Before taking a picture find or give yourself a white spot within that frame. If there is no pure white color in that frame composition you need to temporally bring one in it, say a piece of white paper. Then, instead of risking a picture using one of sunny, cloudy, fluorescent or incandescent light adjustments readily available (usually there is more than one type of light source in any given environment and that makes accurate photographic color rendition a very difficult job) go to the next setting (which symbol looks like 2 little triangles with a circle in between) and push on Set button while keeping camera aimed at the white spot. After a few seconds your camera’s color palette is readjusted and the picture’s colors will look perfect. This is called white balance adjustment and in this last setting you actually ask your camera to define the white spot / paper in your composition as such and read any other color in that composition accordingly. Evidently, when light conditions change white balance adjustment should be performed anew.
I just thought of a question about this color sampling procedure. Define "White."

Arctic white?
Off white?
Pompano Beach?

In other words, since there are so many "shades" of white - wouldn't that throw off the color calculations?
Pure white is R:255, G:255, B:255 in RGB system. Bring that color onto your screen and, providing your monitor is color calibrated corectly (another thing to vector in), see for yourself what other shades of white look like.
Of course, the system is not perfect but for purposes is excelent.
Don't be so tough on colors, Frmar. Color is about light and natural day light is different from hour to hour, from latitude to latitude. Same white bord will look differently under various lightning condition. That alone is enough to make perfect color / matching a futile expectation.
AHA! Thanks, Cornel - light, like life itself, is fleeting!

And this white for calibration purposes is kinda like the old grey card used by film photographers, yes???
You not only got to factor in the monitor but also the room light! I have the light always the same and the monitor calibrated for that light only!
As a pro photographer I never use my lap top to correct color as the room light also is a changing vaule. I shade my monitor in the studio also as that is the monitor that I correct the color with. The print is view for proofing under a special daylight lamp. I had once a large print 13x20 to go over a fireplace with very warm light so the print was printed a little cooler (a litle blue) under the warm light the print look right but under sunlight the flesh tones a little blue. The print never saw daylight again but always the warm room light so it worked.

I am not a framer but have been matting,mounting and framing for about 4 year and I have learn so much from all you fine people thanks

Yes, I guess you're right, sort of gray card calibration from B&W photo film era.
Mike M made it clearer than I what a tough business managing and transferring accurate color information really is. All the settings he was talking about are strictly for his own cooking purposes. Unless (his) those very conditions are perfectly reproduced in some other place no perfectly accurate color info transfer could take place between his studio and that second place.
This is to show that my color info through email method, while not perfect, is still the easiest, least expensive and very likely sufficient method available to most grumblers for, let's admit it, framers don't really need to concern themselves with 100% accurate color matching. I hope that perhaps Mike may tell us how color accurate an instrument human eye is.

Happy New Year to everybody!
Aha, yes - the human eye! Out of my newly implanted lens in my left eye the colors I see are much brighter than the colors I see out of my right eye (which will also have a newly implanted lens by noon tomorrow!).

I have been telling folks I see bright white with my left eye, cream with my right eye and off-white with both eyes together!

And I heard today about a man who was sent to the paint store to buy gold and red accent paints - he came back with peach and pink!!! LOL!

Eyes, indeed...