Thursday, July 21, 2011

My final word on Iodized salt as a restrainer

Once again Reinhold has come forward with an excellent post in his blog :

he clearly demonstrates what one can expect, using ordinary non-iodiozed salt, iodized and comparing that to KBr, all done with the same type of film, and I think he has deliberately chosen a type of film that REALLY will give you fogging, judged on an example of a test with no anti-foggant added that he published some time ago.

His conclusion is simple : non-iodized salt will work, but one has to add more than what is accepted for iodized salt, and one run the risk of another type of fog. dichroic fogging.

Iodized salt will work, and better the higher concentration og KI in the salt.

He also demonstrates clearly that nothing compares to straight KBr, if you can find it, by all means go for that, all kinds of iodized kitchen salt seem to leave a certain fog level, and worse in the cases one really needs an anti-foggant.

Reinhold demonstrates this with pictures of the film, scanned side by side and shown as negatives, very enlighthening, and solid work as always by reinhold, he was and remains the master!

I have come to the conclusion, based on this and other examples from other blogs and net-sources that I need not concern myself any more with this. Reinhold has yet again saved me and other interested workers a lot of hard work and his recommendations are absolutes sound and solid.

I recommend Reinhold's blog BTW, visit it often and read all of it, it is well worth the time, he has put a lot of effort into his work.


  1. Interesting conclusion. I was going to try using salt instead of KBr in PCM but did not get around to it ... reading Reinhold's results has changed my mind and I won't bother anymore as I have plenty of KBr. Good to see this put to bed.

  2. If you realy want to try potassium iodide, you can get it from here:

    The cost is just some small change.
    25 or 50g will last "forever" since you need about 0.01 - 0.02g/L developer. 25g will be enough for more thanb 1000 liter developer.