Daniel M. answered • 10/21/19
Video Editing and Production Specialist
In film photography, using a red filter on B&W film tended to produce dramatic contrast, and particularly in lanscape photos it would darken the sky making it almost black.
On a digital camera you're not going to get quite the same effect because digital camera sensors use something called a Bayer pattern, and a Bayer matrix changes how the digital camera sees colors. Your end result of shooting a digital image with a red filter and converting it to B&W in post is probably going to be a higher contrast image with lots of noise.
As far as digital photography goes, you're more likely to get the result you want by shooting RAW without the red filter, then creating your B&W image in post. A B&W adjustment layer in Photoshop can do most of what you're looking for with the red filter. You could also try experimenting with the individual color channels, which you can find in Photoshop next to your Layers panel in the default window arrangement.
