Sensitometer

[Albin]

Somebody can help me. I am beginner in densitometry. I would like to know how people process to make tests strip with step wedge. What kind of set-up do you use. I try with enlarger and step wedge. I get high density reading. The lowest is 0.79 to 3.32

Any suggestion would be appreciate to build a sensitometer for more tests on films.

Thank You for your help.

 

[Donald Miller]

I use my enlarger for exposures of the step wedge on both paper (initially) and then film as well.

Your density readings indicate a couple of things. The first is that the film is overexposed and the second is that the film is overdeveloped.

Typically one would want a density range (high value density minus low value density--not film base plus fog) of 1.05 to 1.20 for enlarging (dependent on enlarger light source). Your density range of 2.53, while suspect, is certainly beyond that range.

What I would suggest is to decrease exposure by a couple of stops and decrease your development time by an equal amount. Retest based upon that adjustment and then see what your density range is.