Atlanta portrait and wedding photographers Craig & Cathy Willis

770-439-6065

Adjusting for Density and Color by the Numbers


Click image for a fullsized screenshot.

For this lesson, I am using the image that was first posted in the message board thread by Taff.

Others, and myself had pointed out that the density was dark, and yet on the monitor and in print it looks just fine.

This is very possible and yet still be wrong, we cannot just trust our eyes and think our monitor is giving us the correct information when indeed the graph, or histogram tells us different.

I use the information points to make areas that I would read, for both color and density, so I could make the correct adjustments, in order that an image will be viewed well by others who do have a monitor that is adjusted correctly.

I picked two points that should be white/gray on his shirt, and picked the border area that is black and the inside photo area that again is black.

The color is good, but just a little off, but for my taste, I like a little warmth, but if we were to correct it, we would adjust the blue curve and the green curve to bring the value of the G and B up to and equal with the R channel.

Look at the graph in curves to the right, see where it comes down on the exposure long before getting to the right edge of the histogram, well there is a sure indication that the white is not near white. And that is Ok, you can have a different interpatation of any given image, not all white needs to be displayed as pure white. But in this case it is perhaps just a bit too dark of gray.

In the bottom half I made the slight adjustments as I would as if I was to present the image, knowing what the numbers are telling me.

I adjusted the Green and the Blue to give me as close to even on the white point as I could get, remember black (0-0-0) or white (255-255-255) or any gray in-between will all have the same value in each the R G and B areas if the color is correct.

And because the density was a bit low I pulled the curves white point left to near the edge of the histogram as it comes down so that it is more near the right edge, and this will lighten it up to where it will show closer to white then it did previously.

I made this image using Nikon Capture, I have Photoshop CS2 but like the graphs and information and control and sample point setup much better with Nikon Capture in the first place, but this can just as easily be done using any other photo editing software that you might like to use.

I hope that helps.

Craig




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