Weston 877 Densitometer. How to use it?greenspun.com : LUSENET : Large format photography : One Thread
I just bought a Weston 877 photographic analyzer in great shape. It seems to function perfectly, but it is missing instructions. Anyone know how to use it?
-- Andrew Held (Heldarc@hotmail.com), December 20, 2001
Are you still looking for an answer to this? I may be able to help.
-- Jerry Flynn (firstname.lastname@example.org), May 13, 2002.
OK, so I don't have a manual, but I used one of these units years ago at a studio where I worked. Recently, I picked one up on Ebay. Here's how I use it.
First, you turn it on set to "internal meter". A light should come on inside the unit. The meter is activated when you press down on the arm. To calibrate, put something opaque over the lighted aperture, press down on the arm and the meter needle should go to the infinity mark on the scale (infinite density). If not, you can adjust the needle with the adjusting screw just above the meter dial.
Next place a clear bit of film, the edge or something, over the aperture and press down on the arm. Turn the large knob until the meter reads "1". (This knob adjusts the brightness of the light. The smaller, concentric knob is the 'fine tune' on the adjustment.)
Now, move the part of the film you want to measure over the aperture, press down on the arm, and read the density. Now subtract 1 and you have the density above filmbase and fog. I.e. if the meter reads 1.75, you have an effective density of .75.
I hope that helps. You could get a calibrated step wedge to check the acuracy, but this meter seems to work well enough for my purposes.
-- jerry flynn (email@example.com), May 13, 2002.