Krueger Photography

My latest adventure was an infrared photo expedition to the Huntsville Botanical Garden. Although I’ve lived in Huntsville since 1984, I’d never been to the Garden before, but pictorial infrared images need foliage, so off I went.

Film and Developer

In May 2026, I did some new experimentation with with Rollei Infrared 400 and Superpan 200, both of which are reputed to be rebranded Aviphot Pan 200 (pdf). I mixed a fresh batch of Diafine which I chose for multiple reasons:

• Compensating effect to reduce highlight blowout
• Maximization of the film’s sensitivity
• Moderately fine grain

I’ve had trouble in the past with Diafine which I stored it in full wide-mouth amber glass bottles, but I suspect the seal was not sufficiently tight to prevent it from going bad. I’m now storing it in small-mouth glass bottles with the more reliable polycone cap seals.

On the topic of whether Rollei IR400 and Superpan 200 are the same film, I’m not totally convinced that they are. In my experiments, I obtained about one stop greater density with IR400. I’m not certain enough of that finding to argue about it, but I will be buying the slightly more costly IR400 in the future.

Hand Held Shooting

The film sensitivity wouldn’t be a very big deal if it weren’t for the fact that I really want to shoot it hand-held in my Leica M-A or Rollei 3.5E which allow framing without removing the IR720 filter. The main advantage of shooting hand held is, of course, that it eliminates the need to carry a tripod.

Based on my testing, I found no need to stop the lens down to f16 to shoot these near infrared films for focal length from 28 to 105 mm. I just focused normally and shot at f8 all the way up to 105mm on subjects as close as 50 feet. What makes f8 so special is that a shutter speed of 1/30 or 1/60 is fast enough that even someone as shaky as me can shoot hand-held.

Camera, Exposure Index, and Contrast

I uploaded 16 images to the Huntsville Alabama gallery (scroll to the bottom to see them) taken with the Leica using a 28mm lens equipped with an IR720 filter. Thirty-six frames were used to capture 18 scenes, each of which were shot at 1/30 @ f8.0 and 1/60 @ f8.0. An exposure of 1/30 @ f8.0 equates to roughly EI 25 under the bright noontime sunshine. All but one of the prints were printed from negatives that used that exposure and most were printed with a #1.5 contrast filter on Ilford Cooltone RC. The negatives shot at 1/60 were thinner, losing shadow detail and requiring a higher contrast filter. Comparing the Superpan 200 film from this expedition to IR400 film shot a few days earlier and also developed in the same batch of Diafine, the IR400 negatives exposed at 1/60 @ f8.0 were of equal density to the Superpan frames shot at 1/30 @ f8.0. Unfortunately, I can’t confirm that apparent sensitivity difference with more testing at the moment because I’m out of Superpan and IR400 film. It may very well be a fluke.

Uneven Development

One problem I came across during my experimentation with Diafine is that dense, over exposed, negatives showed signs of uneven development. It was more easily seen in smooth total areas like sky, even though the sky itself was not the densest part of the negative. I also experienced reduced density and speed in the film when using Diafine at the low end of its recommended temperature range of 70 to 85F. Both the low temperature problem and unevenness development appear to have been eliminated by pre-wetting the film against the manufacturer’s recommendation, increasing the development time to at least 4 minutes, and agitating (two inversions) every 30 seconds instead of the recommended 60 seconds. I’m not the first to suggest pre-wetting and increasing the agitation frequency with Diafine. Like most people, I tend to stick with manufacturer’s recommendations until I run into a problem that gives me an incentive to experiment.