I have a problem that seems to come and go and is very perplexing. Sometimes when I develop film certain segments of the roll and the exposures in that segment seem to receive different development. The most recent problem this evening showed up where half the negative was lighter. It occurred on exposures 1 through 5 and the others were untouched. I shoot a Mamiya 7 almost always loaded with Tri-x. I always develop in HC-110. My process has been the same for a long time. I always develop 2 rolls of 120 at the same time in a small tank. I do pour the developer through the top of the tank through the filler hole. Should I leave the top off and immerse the rolls in the developer in one fell swoop? This problem happens sporadically. Several times a year I will load the camera with color film and have the lab process it. No problem! At this time I believe that the problem is my process. As I mentioned above I pour the developer in through the top of the tank and I do not stop pouring until all the developer is in the tank. I would think that any lines or uneven development would occur across the films 6mm dimension but the lines of uneven development actually occur in the 7mm dimension. This I can not figure out! Any help would be greatly appreciated.

-- George Zook (513zook@msn.com), November 30, 1999

Answers

Is there a sharp borderline between the two regions of such a flawed negative? In the case of a processing problem, I would expect the line to be soft, diffuse. Also, I wouldn't expect that this is a processing problem because the dividing line is transverse to (and not along) the film (if I understand you correctly). I am not familiar with your camera, but I assume it has a focal-plane shutter? If so, I would expect this shutter to have a vertical slit. In that case, one might suspect the shutter as the cause of the problem. It might just get a bit faster sometimes, or the first curtain stops for an instant, causing the slit to become narrower, thus exposure to decrease over an area of the negative.

-- Thomas Wollstein (thomas_wollstein@web.de), November 30, 1999.

You might ask: Why doesn't it happen with the colour film?

If I understand you correctly, you seldom use colour. So the colour films might just be the lucky ones.

Does the problem occur mainly when it's cold, or humid?

-- Thomas Wollstein (thomas_wollstein@web.de), November 30, 1999.

I had a similar problem some years ago when I was shooting 120 extensively and it seemed to be an agitation/developer level in the tank problem. I went through about 25 test rolls, developing and inspecting till I arrived at a satisfactory solution. I found that when using the recommended amount of developer, the developing tank was almost completely full and left little room for the solution to move. Vigourous (and I mean really vigorous!) agitation solved my problem. Another solution would be to put your empty reels into your tank and fill it up with water until the reels were just covered, but the level is not completely to the top of the tank. Measure this amount (it is sure to be less than the tank capacity) and use only this much developer when you develop. This insures that there is adequate mixing room for the solution in the tank. Hope this helps, ;^D)

-- Doremus Scudder (ScudderLandreth@compuserve.com), November 30, 1999.

Assuming you've excluded the possibility of camera light leaks etc, you're describing insufficient agitation.

Use a double-size tank, load one reel with film and put it on the bottom, and put an empty spacer reel on top of it. Use just enough solution to cover the bottom reel.

When you pour the developer in, bang the tank a couple of times, then invert continously for 30 seconds. For the remainder of the development time, invert the tank two or three times during five seconds every 30 seconds.

You can fit 1 120 reel in a 32-oz tank or 3 120 reels in a 64-oz tank. _Never_ completely fill the tank.

The result will be very evenly-developed film.

-- John Hicks (jbh@magicnet.net), November 30, 1999.

George, Just a hunch, but i bet the problem is the reel you are loading the film on... your color film is fine, so lets focus on your processing. You have been doing it for years.. you probably have a set pattern and rhythm that is consistant. Next thing to question is your developing equiptment. Is the reel is pinching or bendind your film? If so, thats your problem. Your film will be restricting the developing of the film, and possibly even touching. 120 film bends alot easier when it is wet. Let me know if your reel is the problem... Sean.

-- Sean (ZBeeblebrox42@yahoo.com), December 01, 1999.