hello,

I wonder if someone can help me out with the following : I'd like to take pictures in a big hall, full of machines and so reflecting the artificial lights that are everywhere around. I think it's better not to use a flash, but a tripod instead. I already tried (didn't see the results yet) and my lightmeter asked for 10 to 15 seconds (taking into account Schwarzchild-effect), so that's what I did : exposing during 10 to 15 seconds on a tripod. Can anybody tell me whether this is the right way to do it ? I still have some pictures on my roll of film in the camera, so I want to make sure that the last pictures I'll take will be all right. (Since it's someone that asked me to take those picts, it's in color, but I think the way of taking the pictures is not that different from B&W). I would be very thankfull if someone can help me out !!

-- natalie degrande (natalie@inwfsun1.rug.ac.be), July 30, 1998

Answers

If it's in colour, you should worry about colour correction, both for the artificial light and reciprocity failure. The film manufacturer will provide details, and this is the wrong conference for information.

As for the exposure, yes, the basic technique is to meter and allow for reciprocity failure. You should check that the contrast range (shadow-highlight) can be handled by your film. For negative film, expose for the shadows. If you just take a general reflected light reading, then bracketing may be useful.

-- Alan Gibson (gibson.al@mail.dec.com), July 30, 1998.