Black and white contrast filters.

[noseoil]

Please remember that different films see the color differently to begin with. For example, FP4 sees things differently than Efke 25 or, for that matter the old J&C 200. You need to start with the film's spectral response and then go from there. Efke 25 has a bit of an ortho look, so don't use a red filter on it. tim

[BobNewYork]

I think there's some confusion between the contrast control filters used in the darkroom for printing on VC paper, and the filters used on the camera when taking the shot. I think Gary is referring to the use of on-camera filters. The change in contrast with the use of filters on-camera will be entirely dependent on the relative color composition of the subject itself. For example, if the composition were entirely of a deep blue sky and white, fluffy clouds, then a yellow, orange or red filter would increase contrast in increasing degrees. However, if you were to reduce film development to offset this increased contrast you would be merely "undoing" the effect of the filter. I guess in the final analysis, you must ask why you are using this particular filter for this particular shot.

[rob champagne]

I suppose you could measure through the filter to accurately meter your shadows. But I don't think the shadows would change much since they reflect so little light anyway.

There is a high component of blue light in most shadows outdoors and any of of yellow, orange or red filters will have a significant effect on those shadows darkening them.

[JBrunner]

Don't forget that when metering through a filter for B&W that your meter may have a different spectral sensitivity than the particular film. I have found that this can cause measurable variations in calculated exposure.

I have to go lie down now.