To a crisp – An extreme example of edge effects

I’ve been doing target practice and trying out some new-to-me and/or repaired cameras lately with my last few remaining rolls of 35mm Fomapan 100. Since this was all experimental stuff anyway, I went kind of experimental on the development, too, with reduced agitation schemes. And sometimes, this yields kind of funny results. Here’s some for your amusement.

“Oh dear, oh dear”, was my first thought when I saw this. Or actually, the first roll that suffered from this errr…phenomenon.

What happened here? These are some remaining rolls of 35mm Fomapan 100 that I bulk rolled a few years ago. I developed this film in Pyrocat HD dilution 1+1+100 for 12 minutes or so, agitating 30 seconds initially and then a couple of mild inversions of the development tank every 3 to 4 minutes. Apparently this already allowed so much local exhaustion of the developer (and/or bromide buildup) to dramatically reduce the rate of development adjacent to high-density areas.

By means of illustration, take a look at this crop from 1200dpi scan of the image above:

You can see how the high-density areas (the piece of white railing sticking diagonally through the frame, and the white cap on the mooring post) are surrounded by black halos caused by locally reduced development.

In some frames, it really stands out clearly, such as in the image above. Others are somewhat more subtle, although it’s still quite visible, especially if you know what to look for:

Crop from image above:

Sometimes, it sort of works, at least if you don’t enlarge the image too much. It gives a certain ‘crispness’ to the edges – very much like a rather strong unsharp mask. In this particular case, it might have been quite appropriate for contact prints. But 35mm contact prints are kind of tiny…

On a further test roll, I increased the agitation frequency to a few turns of the tank every two minutes. The effect is still there, although it’s somewhat reduced:

Although on some frames where the image structure favors it, it can still be overwhelmingly strong:

Well, kind of fun, but not particularly useful on 35mm film, at least to this extent. I’m surprised the effect is still this strong with 2 minute agitation intervals; it probably has something to do with this combination of film and developer.

Interestingly some rolls I developed earlier with even less agitation (e.g. 45-60 minutes with only some agitation sometime halfway; i.e. “semi-stand development”) did not show this effect at all. I suppose this is because given enough time, the undeveloped adjacency regions have time to catch up a little. There must be a ‘sweet spot’ with reduced agitation and not too long a development time when the effect maximizes itself – or so I speculate.

Oh, and the little Olympus OM-10 I was testing evidently works fine. Because that’s what the point of these photos was, anyway. I got this camera because I happened to have a couple of OM-mount lenses and no camera to use them with, and evidently, it gets the job done. It’s a nice little camera, too!

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