I also have some black and white negative 16mm movie film. For some reason when I tried to use it as a reversal film the sensitivity was also greatly reduced.
I tried some developed as a negative and asa was probably somewhere in the 50-75 range.
When I tried to reverse it the asa was very low. I really couldn't measure it but probably less than 10.
Anyway with a shutter speed around 60 I need about a f4 to get good reversals.
Very strange. Usually people mention increase in sensitivity when doing reversals.
I've had some success rating FP4 at 25 ASA but was disappointed with my following roll that was far too dark and muddy ('moody' would have been OK!)
Using Rodinal as first dev, permanganate bleach and Ilford Multigrade second dev.
Its all good
I'm impressed that others are experimenting with this. When I started out taking movies, I just developed them as negatives, and then printed an unexposed film by winding the film and the negative on a reel and running it through the camera pointed at a white surface. One of my friends' dad was a professional photographer who helped with film, tank, chemicals and advice. He said the negatives should be thin to get a good print. He was right, negatives that looked good for printing on paper made poor positives. I think this is the same rational for under exposing film for reversal. Thanks for starting this thread, it brought me back, as I was 12 when I was first doing this.
Thanks for the posts Steve and Chris. Yep, always wanted to be able to develop my own movie film. Now that digital is the norm I still want to work with film. I developed some super 8 E6 film back in the 80's.
I have heard from many on this forum that for the best b&w positives you need a pretty active, contrasty first developer. D-19 with a touch of thoicyanate comes pretty close to that. I had bought a pouch of D-19 a while back and thought I would try it. When I opened the pouch I noticed the powder was quite brown. I just tossed that and made my own. I had all the chemicals laying around from my experimenting with E6 color process. The thiocyanate is suppose to help clear out the dmin good for projection.
I have never tried the permanganate. I've heard it doesn't have very good shelf life. My chromate bleach has been good for over a year now.
Wow Chris, you actually loaded a double thickness of film in your camera?
That is an interesting solution to that problem.
I like the reversal process in that is solves the negative and printing problem. Of coarse you only have the camera film to work with and the process can be a little touchy !!
I've just picked up a film camera again and started reversal processing because I don't have a darkroom. I find reversal gives an increase in film speed. Using Kentmere film (it's cheap) the 100 gives decent results shot at 200.
I add sodium thiosuphate pentahydrate (6g/ltr) to the first developer (Champion Suprol 1:9) and develop for 12min. Bleach is permanganate (1g/ltr) in 1% sulphuric acid. I bleach for 6min, clear for 2min (25g/ltr sodium metabisulphite), fog for 4min near a 20W CFT in room lighting (not daylight) and then second develop for 10min in Suprol 1:9 but without the thiosulphate. I fix (Champion AmFix 4min) after second development though it's probably unneccessary. 1:9 is the normal print strength for Suprol, 1:19 works well for negatives.
I remove the film from the reel for fogging and I haven't found winding a wet film back on a problem, though loading a dry one on my ancient Paterson reel can be.
Reversal does seem to soften the emulsion when wet, so I let the film dry entirely naturally rather than using a squeegee. I rely on muliple distilled water rinses to avoid water marks.
I have also tried the Kentmere 400 in reversal, shooting at 800 and using the same process (including timings). It did work, but the contrast is a bit flat. I prefer the 100.
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