Regarding CF's, people say it's more of a problem with color than BW. I've just started so we'll see how it goes and what else I have to do. With Covid, this is a good time to get out to shoot as you can be safely by yourself breathing fresh uninfected air.
Two things, any neutral density filter, no matter how good and what CFs essentially are, will start to turn red over time. Not too big a deal with black and white. With digital, this is no big deal too since you can correct for this easily in Capture One using the lens cast correction. (I have to do this no matter what, so it is not a big deal.) With film, it would become impossible to fully correct for it. Since a CF graduates from dark in the center to light on the edges, any cast that develops over time will eventually be effecting the color of the film inconstantly.
Second, if the using a CF extends a longer shutter speed to being over a half second, then reciprocity comes into effect. Although reciprocity does effect black and white, it only does so on exposure. On color, it also effects color and what color correct filter you need to use. Now, when shooing with negatives, this not as much as a concern. With shooting color positives, you need to nail the color, and adjusting for reciprocity was a real pain in the a$$.
