cbtsam wrote:
I keep encountering advice to shoot during the blue & golden hours, and I can see how that advice would pay off for color shots. I haven't shot B&W for about a half century, so I'm not clear: would that advice hold true for B&W shooting? Or would it just result in lots of blown whites and/or blocked up blacks?
In my experience, shooting during golden hour is like shooting under a color temperature of around 2700K-3400K if subjects are lit by sunlight. This would be like shooting through a yellow filter, compared to any form of daylight lighting. Blue hour, based on some carefully controlled work I did a couple of years ago, is like shooting under a color temperature between 10,000K and 20,000K, depending on how long it has been since sunset. This would be like shooting through a blue filter (or a very blue filter, in the case of 20,000K). This means that relative tonalities of different colors will be altered. In my experience, those alterations can be significant. Of course, to see the effects of these shifts, you will need to change your color temperature to 5800K in post processing before you remove the color from your exposures.
I have had better results during these times by exposing using a fixed "daylight" white balance, using black & white camera created JPEG images instead of decolorized raw images, and working very carefully to get the initial exposure correct. This almost always means using a tripod after the sun sets, and usually even before.
If you feel the need to use raw images instead, and if you want to see and take advantage of the extreme color temperature shift, it is critical that you return the color temperature to 5800 BEFORE desaturating your image, them leave it there.
Of course, there is another approach to this time of day, and that is to retain color and adjust white balance to 10000 or 20000K, restoring natural color to the images. This effect can produce breathtaking results because of the "whole sky" illumination of your scene. In some cases, it is even possible to capture extremely dramatic cloudscapes in the western sky with basically no work at all. For this, you will have to have the raw file, because there can be an incredibly wide range of intensities in your image. I haven't done much of this in B&W, but have treated some color images this way. I'd expect similarly dramatic results in black & white.
I haven't found a lot of guidance in this area that I felt was applicable or that fit anything that I wanted to do or that produced results similar to what I was seeking. So most of what I do is guided by approaches and procedures that I've made up on my own. My suggestion is to take what you already know as a starting point and experiment on your own. Take notes so that you can recreate those results that you like.