Black and white: optical filters in a digital world

Searching through the internet for a definitive answer on whether or not coloured optical filters still play a role in digital black and white provided an answer as clear as mud: yes, no, and everything inbetween. So let's see if we can find some clarity ourselves...


Here are some shots taken with various coloured filters compared to shots taken in colour and converted in Photoshop with the equivalent digital filter, all shot with sunlight white balance:

Red:



Optical filter (left) vs Photoshop filter (right)

 
Clouds cropped for comparison;

Optical filter (top) vs Photoshop filter (bottom)


Yellow:


Optical filter (left) vs Photoshop filter (right)


Clouds cropped for comparison;

Optical filter (top) vs Photoshop filter (bottom)

 Green:


Optical filter (left) vs Photoshop filter (right)

 Clouds cropped for comparison;

Optical filter (top) vs Photoshop filter (bottom)


Upon initial observation, there is a demonstrable difference between optical and Photoshop filters, with the edge going to the optical filters. There is more detail in the cloud and shadow areas with the coloured filters, while the "shopped" versions seem clipped at both ends in an attempt to give the image some enhanced contrast.

With enough time and play we could probably match the output of the optical filters in Photoshop (as opposed to the one-click presets under the B&W menu). However, as I prefer taking pictures over sitting in front of the computer, the more I can get my pictures to where I want to take them in camera, the happier I am.

In the next installment we'll take a look at how a custom white balance affects our black and white photos...