Response to Alternative to Xtol

Russel, I forgot this. There are very effective ways to increase true filmspeed. Mercury vapor – no forget it, you do not want to poison yourself. All vapor methods work best with low speed films. There you can get huge increases. Well, mercury is obviously the exception. It seems to work with all sorts of films and speeds, but again I can only urge everyone not to use it. It also has some side effects such as very noticeable grain. Raising the latent fog level is the other method. I once took several rolls of TMAX 100 on an airtrip (at the time when I did not know there also were decent B&W films on the market). It was bulk loaded and I had run tests before on the same batch. At that time I used D76 1:1 made from scratch and the speed rating was around ISO 50. After returning my redone tests showed a speed increase of 100% due to what must have been the Xray security checks at the airport. Try to get this speed increase with pushing or "effective" developers! I would judge that putting a film through the machine 6 times (that was about the amount it must have had due to changing planes) will raise the toe of the film that much. In the literatue there are many other descriptions of how to "preflash" film, all of which are tedious at least: Unrolling film, pinning to the wall (off course in total darkness), taking a flashgun, using the auto setting and setting it off at a very close distance to the opposite wall. Nothing for me. Also rewinding film in a 35mm camera quickly in the darkroom with open shutter and in front of a red safelight does not sound very repeatable. A trip to the airport with a bag full of film and getting acquainted with the security personnel might solve some of your problems – and it would be extremely cheap despite the beers you hight have to buy. Flashing or Xraying by the way also works after taking pictures! You could also take exposed films to the airport. Only make sure that you select a "film safe" machine. Some experimenting may bring even higher speed ratings, depending how often you put the film through the machine before visible fogging occurs. With high speed films you probably should put it through the machine less often, since the threshold for visible fog obviously is lower than with a medium speed film. Also the effective speed increase also will be lower than in the case of low speed films. According to what heard and read it should be fairly easy to increase the effective speed of an ISO 25 film to ISO 100 with flashing. Additionally you would have the benefit of softer tonal rendition. I have not tried it though.

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