Color Digital Camera Stills Converted to B&W

When I converted the photos to B&W I struggled with the process; whether to remove the color and then adjust the tonal range or reverse the process and eliminate the color last. Anyone who is familiar with Photoshop knows there is almost always more than one and sometimes several methods of getting to a final result. I initially choose to add a Hue/Saturation Adjustment Layer as the final layer to desaturate the stills. That allowed me to adjust the RGB levels independently (black, gamma, white) and then remove all remaining color (Saturation = -100). The basic grade to B&W goal was to match the blacks, match the upper left corner of the 18% gray patch and the lower left corner of the white in each still. Otherwise the tonal range was left to do what it would. The B&W versions of those stills are below in the "This Row Desaturate Last" rows. Later I tried the opposite approach where I filtered the color first, then adjusted the black, gamma and white levels and found the results were basically the same.

Then I changed the processing to yet another approach where the images are first converted to Photoshop's Grayscale Mode. There the tonal range started looking quite different from the originally graded B&W photos. The daylight+yellow sky darkened considerably and the Daylight+CTB sky lightened. The density of the skies in yellow-green color and grayscale stills are much closer to being the same. This method, while very workable in Photoshop or other image editing programs, may or may not have an analogous approach in a telecine suite. In the still editing system of grading you have a black = 100 and white = 0 scale, a reverse ire scale if you will, but only in one vector. Uh, starts to sound like luminance signal video. Those photos are in the "convert to grayscale mode first" rows. Here the overall densities of the B&W stills begin to look like those of their color counterparts. The effects of desaturation vs grayscale conversion on NTSC color bars can be seen at the top of the photo comparisons. Thanks to Dominic Case for that idea.

David Mullen inspired me to look at the individual channels (R G B) of the original stills and those separations can be seen here.

The last row on this page is just too satisfy my curiosity about the effect of a red, a more than full CTO and a chocolate filter. Maybe in the B&W film world these would have an effect. Here I can't say the same.