I've heard that shooting with tungsten light source makes a film (B+W) underexposed about 1/2 stop if I expose the film accoding to meter reading. Is it true? thanks susumu

-- tanaka susumu (susumu@aol.com), July 22, 2000

Answers

It depends on the spectral sensitivity of the film (and meter). Many of the films that are "panchromatic" are a little deficient in response on the red end of the spectrum, add to this the possible metering errors in reading the light, and you can be off by 1/2 stop or more.

-- Wayne DeWitt (wdewitt@snip.net), July 22, 2000.

I'll second Wayne's reply. Kodak used to give recommended daylight speeds and Tungsten speeds for their films. FI Tri-x is rated as 400 ISO in daylight and 320 ISO for Tungsten.

-- Pete Andrews (p.l.andrews@bham.ac.uk), July 24, 2000.