Response to the zone system and the use of filters

I don't understand how a meter can be corrected to handle orange and red filters in B&W photography correctly for all films, since different films have different color sensitivities. I am not talking about special purpose films, but the ordinary B&W films that most people use like Tri-X, FP4+, TMX, Delta 100, etc. Kodak publishes specific filter factors for their films (on the US Kodak web site) and you can see there is a difference in the filter factors specifications that they give for each of their films. There is also a different rating for daylight and tungsten. Based upon my experience there is also a difference in the nature of the daylight itself, such as humidity, time of day, etc. Not to mention the difference between shadow areas and sunlit areas of the scene. I don't know how any meter can be corrected to handle all these situations automatically. As Ilford says on their web site, TTL meter readings can be underexposing as much as 1 1/2 stops for orange and red filters (assuming that the TTL meter is accurate without the filter).

[ Previous | Next ]