Making 8x10 zone system testing a little cheaper?

[bob moulton]

I second the use of the step wedge. You can reduce your film costs significantly. To save even more money, cut the 8x10 sheets up into 4x5 pieces. then you can test the actual film stock without the cost. If you want to practice tray developing 8x10 sheets in your tests, then use the stouffer step wedge and purchase the software from BTZS for use with it. You will have to use at most 6-8 sheets of film.

One possible problem--you will need access to a densitometer to read your negs. if that is a problem, then use the BTZS testing procedures.

[Eric Woodbury]

The step wedge method works very well. You can make your own step wedge by using cheap NDs from Lee or Rosco. Buy a 0.3 ND, this is one stop, and a 0.9, 3 stops. Cut them up and overlap them so you get a clear, 0.3, 0.6, 0.9, 1.2, etc. (They add, i.e. a 0.9 overlapping a 0.3 gives you 1.2) From 0.0 to 2.4 is nine stops and this is plenty. Put in front of neg and expose nine zones all at once.

There is another way without a step wedge that creates the same thing. Insert a sheet of film into your camera. Point camera at an evenly lit surface and expose the entire sheet of film to zone I. Then insert the darkslide just a little bit, covering about 1/2 inch of film. Now expose that to zone II (this is the exact exposure you gave it for zone I because 2 times zone I is zone II and you already gave the entire film half a zone II exposure...does that makes sense?) Move the slide in a little bit again and add one stop to the exposure. It is best to do this with f/numbers as they are more consistant (at least they feel that way) than shutter speeds. Now push the slide in again and add another stop and expose again, etc, etc. Develop. This gives a sheet of film with zone stripes on it.

[Steve Williams_812]

I just completed the film speed index tests, development time tests, and minimum exposure for maximum black prints tests for 8x10 TXP320.

If I had a 4x5 reducing back for my camera I would have cut the film down to save a few bucks, but in the end I am glad I just went ahead and did it.

It took me 6 sheets of 8x10 to determine my Zone 1 density of .10 over film base and fog at ASA400 (That was a switch from my normal speed of 250 in 4x5).

Then I exposed 4 sheets at Zone VIII and another at Zone I. Processed the I and VIII in HC110 Dil B (570ML volume in JOBO 3005 drum) and was damn lucky to have the development time right the first try. 4.5 minutes at 68F. I through the other 3 sheets out.

I used 2 sheets of Ilford Multigrade Fiber 8x10 to determine minimum exposure time for maximum black with the filmbase and fog neg.---18 seconds at F32.

Used 1 sheet of paper to determine that the Zone VIII printed correctly at 18 seconds.

I was done--- 10 sheets of film, 3 sheets of paper, chemicals and time. It could have taken more, but the tests consumed under 50 bucks of materials. I have since shot a dozen sheets and each proofed great at 18 seconds at F32.

steve

[Hernán Villar]

Get a board and cut it coping the slit of the film holder make 4 and open a hole in each at different highs so you make different exposure on one sheet of film. I read it from Minor White
Sorry my english