Using Tech Pan with filters : LUSENET : B&W Photo - Film & Processing : One Thread

Just curious if anyone has used tech pan film with filters. I know it has an increased sensativity to red light. Thus, what effect does a #25 red filter, or a K2 yellow filter have on the image? Thanks in advance for your responses.

-- Josh Randall (, February 12, 2000


It's pretty contrasty already so be sure you have a really good reason for using filters with it.

-- Mr.Lumberjack (, February 12, 2000.

Also remember that a filter blocks its own color. Pat

-- pat j. krentz (, February 12, 2000.

Regarding the last post... I believe that a filter transmits its own color, and blocks those opposite on the color wheel. Therefore a red filter would have the effect of increasing the apparent red sensitivity.

-- Henry Friedman (, February 13, 2000.

If you photograph a red barn and allow for the filter factor, you wind up with a white barn basically, if you do not allow a filter factor you will have the tonal value of a red barn, try it. Pat

-- pat j. krentz (, February 14, 2000.


That is not a contradiction to what Henry said. In the shot with the exposure without filter factor allowance, the filter might leave the red areas basically unchanged, while darkening (in the print) all other areas. If the statement in your previous post were true ("Also remember that a filter blocks its own color. Pat") the red barn would be black (or transparent in the negative) in a photo not taking into account the filter factor.

-- Thomas Wollstein (, February 14, 2000.

Tom, you are right about filter factors, where I went astray was I don't use them, so that when I photograph a red rose I do not allow for a filter factor and my roses come out very dark which in the gray scale approximates what I would call dark red, in the negative it is very light exposure which prints very dark. Sorry about the confusion on my part. Pat

-- pat j. krentz (, February 15, 2000.

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