that made my day!
Originally Posted by Graeme Hird
(I never shoot any thing - and I can't stand that expression...)
Chuckle. Another Aussie tricked by the title. Bit hard to get a sheep to sign a release form.
Sorry off topic.
Originally Posted by JG Motamedi
Thanks for the PDF. It's good to get another point of view on this matter.
About the stains. The attached image is an extreme example of it.
I don't think moist can be the problem and I do heat my plates with a hairdryer just before I expose them to iodine.
I had problems with insufficient vapour and I upgraded my coating box with a heating element but that turned out too heavy. Plates looked like classic B&W emulsion after only 30 seconds. I have to finetune this as I easily loose the spectral colours and get a greyish blend, even if I only activate the heating for 20 seconds and wait for about a minute to start exposing.
I suspect the problem is that the fumes are too localized; I would then guess that either there isn't enough space in the box for even coating or there aren't enough fumes. Perhaps the iodine is too close to the plate? My box has about 75mm between the iodine and the plate. Is you iodine evenly dispersed through out the box? I have never paid much attention to this, but if the iodine is too close to the plate this may be a possible cause.
I would be very concerned about heating the iodine. I think this is very dangerous and not at all necessary. At a room temperature of 20 degrees, iodine should easily produce enough fumes. Usually I try to "build up" fumes in the box before inserting the plate. Would it be possible to do this with your box? Build up the fumes for 15 minutes (with no heat) and then insert them?
The distance could be a problem. I guess it's only 50 mm away from the plate nuw but to improve this I have to build a new bottom section for my box.
I lost some time because I had no clue about the sort of reaction I had to expect from Iodine. I remember leaving the box out in te sun for hours without any visible reaction. (that was with a dose of bisublimated Iodine - tiny little balls)
Then I used crystals. I expected them to react in mid air but again nothing happened. So I sealed the inner tray of my box and put it in the sun again. You can see the different tints of vapour that I obtained. Can you hint me on how intense it should be?
I know the heating sounds tricky but my box is sealed well and I wear a high quality breathing-mask at all times.
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