I am going to attempt to do a "guy thing" and calibrate the filter setting on my Omega D5XL with a Super Chromega dichroic. I have read through some previous threads and also some other literature so I think I have some pretty good information to work with.

The only thing I haven't been able to find is info on the specific step table I should get, and where I can get it. Also, should I get a step table that is calibrated or uncalibrated (I have read that calibrated is better, but I don't know what the difference is). Also, should I use a 4x5 or 35mm step table in a negative carrier, or contact print? And do I need to drink beer while I am doing all of this?

Thanks in advance for any help you might be able to give me. If I am successful, I may even try trying to determine my paper speeds and things like that. But one step at a time....

-- jennifer (photomatic99@yahoo.com), April 26, 2002

Answers

One warning about drinking beer in the darkroom. After Dektol has been in the tray a while, it takes on that golden color of beer. Be careful you don't mistakenly put you prints in the beer instead of the developer, it will quickly ruin your beer!!!

-- Ken Burns (kenburns@twave.net), April 26, 2002.

My favorite is a Kodak #2, the smaller one, with 21 steps at 0.15 intervals (half stop steps). The uncalibrated ones are generally almost dead on, just like the calibrated ones. A rule of test is "test it the way you use it", but I just do a contact print. It's not exactly the same, but plenty close enough. I'm not terribly fond of beer, but find that a rum and Coke, or Southern Comfort and Cranraspberry juice makes the test process much more enjoyable. Unfortunately, it can also make the numbers a bit harder to keep track of. Seriously, what you're about to do can be quite interesting. You might take a look at Ctein's Post Exposure for a good read on paper charactoristics and how to match papers to films. You'll also find that some papers perform very poorly at low or high contrast settings.

-- Conrad Hoffman (choffman@rpa.net), April 27, 2002.

Greetings,

Step tablets are available from Stouffer Graphics http://www.stouffer.net/

They have all sorts: 35mm, 120 & 4x5 in 21, 31 & 41 step, etc. They also have single strip tablets similar to the Kodak. With the 21 step tablet each step is 1/2 stop or 0.15 D.U., 31 steps is 1/3 stop or 0.10 D.U. For paper testing I find the 31 step tablet best.

The only difference between the calibrated step tablet is that each step has been read with a densitometer and the actual reading noted on the package. In real life this means that each step on a 31 step tablet may not be exactly 0.10 D.U. apart. One may be 0.09 and the next 0.11, but the net results are insignificant for what you are attempting.

For the most accurate calibration, you should project the step tablet just as you would for an enlargement, but that's taking things to the extreme. Contact printing the step wedge works well too and for contact printing, I recommend the 4x5 size or the strip.

Regards,

-- Pete Caluori (pcaluori@hotmail.com), April 29, 2002.