Making 8x10 zone system testing a little cheaper?

[Don Wallace]

I want to do some zone system calibration for my 8x10 camera and I am getting discouraged by the cost, were I to take the same route I did with my 4x5. All I really need is enough film area to use the densitomer. Would it really make any discernable difference? Any other suggestions?

OK, so I'm cheap.

[Tim Curry]

Seems to me you should be able to use the results from your 4x5 and just apply them to your 8x10. I think it would be better to calibrate your 8x10 equipment (shutters etc.) to a known standard of performance. This way your test results for one format of sheet film should match another.

Has any of your 4x5 equipment been checked against a known standard? If so, your film tests are already done.

[Don Wallace]

Tim, the problem is that I calibrated my 4x5 for rotary processor development. I will be using trays for 8x10. Sorry, I should have mentioned that.

[Edward (Halifax,NS)]

You could just recalibrate your 4X5 for trays. That would save you some money.

[j.e.simmons]

Fred Picker used to tape film into a larger film holder - for instance two 4x5 sheets into one 8x10 holder - for testing purposes. He did it so he could be sure he had two identical exposures.

That said, I don't see why you couldn't tape 4x5 film into an 8x10 holder, even one sheet to a side, for your tests.

I'm assuming. of course, that you're using the same film in both sizes.

[Andrew O'Neill]

You could test your 4x5 in a tray instead of 8x10 but then you would probably have to adjust the time when you do develop 8x10 sheets. Or you could make the "zone board" as outlined in Gordon Hutchings' book, The Book of Pyro. You can record all zones from 0 to X on one sheet of film. You only use 5 sheets of film to get a family of curves. Plenty of room for reading with your densitometre.

[Donal Taylor]

I'm still not entirely clear why you need to "do some zone system calibration for my 8x10 camera"

Why not just to everything with your 4x5? The camera shouldn't make any difference?

[David A. Goldfarb]

I can understand wanting to calibrate for different cameras. The camera is not the issue so much as the processing method, the difference in contrast of the lenses (many people might use more modern lenses for 4x5" than for larger formats), and possible differences in shutter speeds.

A neat method that I've seen for the film speed test, but haven't set up for myself yet, is to take a darkslide and drill 6 or 8 large holes in it with a keyhole saw, each one covered with a mask, and use this darkslide to make 8 exposures on one sheet. The only problem I could see would be with wide lenses, where illumination might fall off toward the corners, so be careful to use a normal or long lens, where this isn't a problem.

[KenM]

You could also use a step wedge in-camera. Sandwich a piece of film and the step wedge together, and insert it into the film holder. You may have to try a few film holders to find one 'loose enough' to make the fit not-to-tight.

Find a bright surface, set your film speed to the manufacturers speed, and expose the surface on zone X while focused at infinity. Since the step wedge acts as a neutral density filter, you'll get a full range of zone exposures on one sheet of film. With a 21-step wedge, each step is 1/2 zone, a 31-step wedge will have 1/3 zone steps.

The only problem with this method is that the step wedge is pretty expensive - $78 from Stouffer for an uncalibrated step wedge...

[Jorge Gasteazoro]

I know this is not what you want to hear, but if you did the BTZS testing method all you would need would be 5 8x10 sheets processed the way you want. On that vein, why not let the View Camera Store do the testing for you. Give them a call and ask them about their procedure. I have heard people who have used them have been very pleased with their results. From what I understand you expose a step wedge on 5 sheets of film, develop it and send the develop sheets to them, they do all the analysis and send you the results back.

Good luck.

[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