Clip tests with 120 film

[What About Bob]

For those out there who do clip tests: Do you prefer to cut 120 film in half, thirds? Knowing where to cut, in between frames, would be difficult. These tests will be for determining bracketed exposures and development times.

In the past it was much easier with bulk loaded 35mm film to load a handful of frames per canister and label the canisters with taped information.

 

[F4U]

I know of no practical way of doing clip tests on 120 film. I've done many on 35mm using a Lloyds loader to load my own. But on 120, there is no feasible way. As for finding developing time, the time and temperature charts are your best bet, along with cutting off a length long enought to stay on the reel and just exposing it to room light and developing. Idealy if the developed piece is not so opaque that you can' still see a light bulb through it then you're OK on that test. As for exposure, box speed is a good place to start, assuming a good exposure meter and a proper shutter speed calibration. It's that last point which is your biggest worry. I work on shutters. Old iris shutters are notoriously bad in their accuracy. So much so, that most testing is practically hopeless until the shutter is serviced. Too many variables negates test results until that very first link in the chain is nailed down. It's the weakest link. In 35mm, not so much so. A 40-50 year old Japanese focal plane shutter is ofen still reasonably accurate at 1/125 and below. An old iris shutter is nowhere near accurate at any speed.

 

[What About Bob]

I have a Watson loader. It still has some old Tri-X from the late 90s in it. I have been using tiny pieces of that film from time-to-time for testing fixer strength and for developer activity. Whatever is left in that loader will not be of any use except for testing. It will be fogged greatly. I had developed a roll some time ago and the results were very bad. In fact I should be able to use a piece of that film for getting a good idea on the bleaching time. Just have the film piece swim in the developer until it hits full black then wash it off then put it through the bleach and inspect how long it takes to go blank. Maybe add an extra 30 seconds to be sure.

This clip testing will be toward doing black and white reversal. I have done E6, in the distant past. This will be the first time doing reversal with black and white. There will be more variables to contend with. This will be part of the excitement. Looking forward to it. I am set to start this in the next few days.

I will be using a Minolta IV meter. All of my Hasselblad gear was serviced last year. Yashicamat 124G and Rolleicord were serviced as well.

The variables to be determined will be the personal film speed, first developer time, solvent amount for the first developer, re-exposure amount and time, and second developer time. Re-exposure and second developer shouldn't be too critical. Pretty much to completion. Temperature will not be problem. I'm hoping to get an idea on what the best results will be within the third or fourth roll; for this combination of film, developer, and rest of the process.

I will be keeping notes of every step in worksheets as I go along. One good thing about voice recorders: Say it now and write it all down later. If anyone is interested I can make a thread about the progress and results. I'm basically following Ilford's instructions with the exception of the bleach. I will not be using a permanganate bleach but I will at some point. From what I have researched, over countless hours and sleepless nights, I believe that permanganate bleach will add to an extra variable and could potentially cause ruin of the film because of the emulsion being more fragile, even with using a diluted working solution of permanganate. For right now I want to lessen as many variables as I can.

 

[BobUK]

My Rolleicord Va TLR has a changeable back for cut film, 2.5" x 3.5" I think.
It came with about five cut film holders, and a ground glass viewing screen.
I made a simple jig to cut 120 film to the correct length.
I used it to help find workable exposures and developing times for Rollei Infrared films when almost opaque dark red filters are used over the taking lens.
Using a cut film holder is a bit fiddly and slow.
Definitely needs concentration to use, or you will end up with a few duff pieces of film, the same as every 4x5 film user has done in the past.

Cheers.

I forgot to mention.
The cutting jig that I made has a stop to cut the film to the correct length for the dark slides.

 

[pentaxuser]

For those out there who do clip tests: Do you prefer to cut 120 film in half, thirds? Knowing where to cut, in between frames, would be difficult. These tests will be for determining bracketed exposures and development times.

In the past it was much easier with bulk loaded 35mm film to load a handful of frames per canister and label the canisters with taped information.

In most , if not all cases, aren't clip tests use to establish film speed dev time etc with the equipment you use.

With the exception of the camera won't these be the same. In the case of the camera is it not possible to check the exposure of the 120 camera against that of the "test 35mm camera with the same scene and adjust on any difference that is revealed

So doesn't testing on short bulk rolls in 35mm get you close to what you need to know with the 120 and avoids using a 120 film?

I may have missed vital aspects that only using 120 film will reveal of course so what might these be?

If using 120 film is essential for a test then doesn't the Bill Burk ND 0.30 test cover it where in effect the film can be used for "normal " photography as all shots will produce usable negs for printing but the ND filter test gives you a yardstick for judging film development?

pentaxuser

 

[retina_restoration]

For those out there who do clip tests: Do you prefer to cut 120 film in half, thirds? Knowing where to cut, in between frames, would be difficult. These tests will be for determining bracketed exposures and development times.

In the past it was much easier with bulk loaded 35mm film to load a handful of frames per canister and label the canisters with taped information.

In years past, I would sometimes cut a roll of 120 into thirds and develop each in a different developer, to compare the various effects. I still occasionally do these kinds of tests, but I now prefer to simply cut the roll (approximately) in half and compare only two developers (or methods). Inevitably, there is some bracketing involved, and I find it easier to work with six frames per test "clip". There's zero chance you will cut precisely between frames, so don't even worry about that. I often find that the frame that is cut in half tells me a lot about what happened.

 

[MattKing]

What is your reason for not using for the tests the equivalent 35mm film instead?
Is it due to the difference in the substrate? That would certainly be relevant to making transparencies from it.

 

[What About Bob]

In most , if not all cases, aren't clip tests use to establish film speed dev time etc with the equipment you use.

Yes

With the exception of the camera won't these be the same. In the case of the camera is it not possible to check the exposure of the 120 camera against that of the "test 35mm camera with the same scene and adjust on any difference that is revealed

So doesn't testing on short bulk rolls in 35mm get you close to what you need to know with the 120 and avoids using a 120 film?

First I would need to resolve some issues with the K1000 before testing. For the time being I had to put that project on the back-burner. I hope to return to that project someday.

Purchasing Bulk T-Max is out of my reach. I would get a single roll for testing.

I remember seeing charts that had shown slightly different development times for different formats of the same type of film but the results should get me close.

 

[bernard_L]

For those out there who do clip tests: Do you prefer to cut 120 film in half, thirds? Knowing where to cut, in between frames, would be difficult. These tests will be for determining bracketed exposures and development times.

I do something equivalent from time to time. So far, not really as a clip test but because I'm impatient to see results after an outing and don't want to waste good film. Note that this is done with MF cameras that work either with red window, or by aligning arrows before closing the back.
Advance the camera to the next unexposed frame. In darkness, open back. Feel the frame window and cut the film (only) closer to the leading side. Have a piece of masking tape ready, and tape the head of the remaining film. Detach the take-up spool, unwind, pick up the exposed film, detach from backing paper, don't leave the tape in place. Detach the supply spool, and carefully rewind film; check for a possible bulge if the (new) leading edge needs re-aligning; also check for protruding masking tape. In the process you lose one frame --where the new tape is-- but you gain the knowledge to develop properly the rest of the film.

• Case (a) splitting the development of a completely exposed film. You lose one frame, hope it was not the keeper. You might even skip intentionally one frame mid-roll if you foresee to develop the beginning N+ and the end N-
• Case (b) partly exposed film. You will use the remainder later --next outing; continuation of tests, whatever. If your camera has auto-detection, you are on your own. Maybe the camera will auto-detect the new leading edge of the film.

So much so, that most testing is practically hopeless until the shutter is serviced.

Not quite. The test can be meaningful as long as the actual shutter speed is measured.