densitometer

I am planning on trying my hand at some contact printing with gum

bichromate and platinum palladium and maybe some other alternative

processes. I keep reading about needing a densitometer to check

density of negatives to pick out the best one for contact printing.

At present, I can't spend a small fortune on one of those things, so

I am not sure how to proceed except by trial and error and that can

become expensive pretty fast. Does anyone have information on any

other method or rule of thumb exposure guide to produce good

negatives. I'll be using a 2 1/4" and 4 x 5 cameras and mainly

shooting portraits with hot lights. HELP!!!!!

you need to choose a film and developer combination that results in a high density neg, say Tri-X & PMK/Pyrocat or HP5 & Pyrocat. most people say a 1.4 density is what you are looking for in you negs for platinum, gum will work well for that, and slightly less as well. if you use a staining developer (pyro or catechin) the spectral density can be quite a bit more than the physical density of the silver. you need to just go through trial and error if you aren't able to do measurements with a densitometer, there's no real way around it. I would establish your effective film speed before adjusting develoment for UV contact printing.

 

the more important thing realize is that you can get a good densitometer, USED; for a couple hundred bucks. buying new doesn't make any sense for anything other than a business environment. got to X-rite.com and look at their literature to get an idea on what model you want, and then search the web/ebay for a deal!

Hi David, if you get the Bostick/Weese book "The new platinum print" there is a section there about using a visual "densitometer" which mainly is a black card with two punch holes you put the part of the negative you are interested under one hole and put the step wedge under the other hole and you slide the step wede until you reach density that "look" the same, all this done on top of a light table of course. You will be surprised at how accurate you can be doing it this way.

 

 

Having said that, I would really recommend you to save your pennies and get one, the x rite 810 usually goes for 200 to 300 bucks at e bay. I do the BTZS method and I usually get the correct exposure and contrast on my first try with pt/pd. I do up to 12x20 so I cannot make too many mistakes.

Hi

 

If you truely want to use a densitometer to read your negative, and if you havee computer, a scanner which permit to scan film (like espon 3200 or other). the easiest way and the cheapest will be to buy a software like vuescan. It will allow you to read the density of your film.

 

regards

I finally bought a densitometer. But for years I would use the one at a local shop. At first I would ask them to do a quick read of a negative and eventually they would just let me use it.

There is an Xrite 361T just posted on eBay. It is the one densitometer

that will do UV as well as normal B&W. This is very useful if you plan

on doing PYRO and Platinum prints. See Bob Herbst's article about this

densitometer and its use in a recent issue of View Camera Magazine.