rherz
Hello,
I really need to get this frustration off my chest.
Either I’m getting bright spots in the shadows on my black-and-white slides because there wasn’t enough light during the second exposure – that happens when the whole process takes place underwater. And that’s despite using a 150-watt halogen spotlight for 5 minutes on each side.
Or else, when rewinding after free-hanging exposure, the emulsion is scraped off at the contact points with the reel and then spreads across the entire film. Rinsing after rewinding didn’t help.
The slides I’ve seen look very good, i.e. the chemicals, times and movement seem to be fine.
Does anyone have any good ideas – ideally, I’d like to leave the film in the spiral.
Best regards
Robert
Gast
Hi Robert,
I’ve just come out of the darkroom. I developed my very first roll of FomaPan 100R today. I haven’t seen them on the projector yet, of course, but they look very good. They have a relatively warm tone; some seem a tiny bit too dark, but not all of them...
Development times for the chemicals, exactly as per Foma’s instructions.
Regarding the double exposure:
I took the whole spiral (plastic, Jobo) out of the tank and placed it in a water bath, then exposed each side for 7½ minutes using a 60 W incandescent bulb held about 10 cm above the spiral.
No guarantee of success, but it worked quite well for me. However, tomorrow, once the film is dry and mounted, I’ll take a close look at it; I’ll post the result here again and upload scans to the internet as soon as possible.
Good luck,
Alex
Gast
Hi everyone,
Here are the scans, as promised:
www.cocodiablo.de/SW.htm
Best regards,
Alex
Gast
Hi Alex,
I’ve had a look at the photos from the zoo.
Did you lightly colour the scans (brown) in an image editing programme? I don’t think I can see just shades of grey.
Best regards,
Roland
Gast
Hi Roland,
No, I’ve only scanned the images; I haven’t coloured them in, cropped them or done anything else...
I scanned them using a Canon FS 2710 and the software was XSane.
Best regards,
Alex
Chris
My slides have a slight brown tinge too, for no apparent reason. Unfortunately.
When you look at them, they actually look quite nice, with that slightly vintage look, but I haven’t managed to get a really clean grey gradient yet... Could that be down to the Bleach bath? And what exactly does the fixing bath do afterwards?
rherz
Hello,
The stop bath removes the brown residue (manganese something-or-other) produced during bleaching. If the slides are still brown, simply increase the stop bath time – for me, it was about a minute less than the bleaching time. If the slides are too light, reduce the primary development time slightly.
Best regards,
Robert
cfb_de
Hi Robert,
That "manganese something-or-other" is manganese dioxide. It forms as a reaction product of the potassium permanganate in the Bleach bath.
Have a nice weekend,
Franz
kessler
Hello,
The stop bath removes the manganese brown (or whatever it’s called) produced during bleaching. If the slides are still brown, simply increase the stop bath time – for me, it was about a minute less than the bleaching time. If the slides are too light, reduce the initial development time slightly.
Best regards,
Robert
Hello,
If you’re feeling a bit more daring, you might be better off using a dichromate bath for bleaching again, then rinsing VERY THOROUGHLY (>5 mins) and using a standard clearing bath (sodium sulphite or sodium pyrosulphite). The base will then be really clear and the image free of any colour cast!
Of course, the dichromate solution must not be allowed to enter the sewage system and you must avoid any skin contact, as the stuff is carcinogenic
Best regards
Martin
cfb_de
Hello Martin,
Not only should you avoid skin contact with dichromate developers wherever possible, but it is even more important not to inhale any dust whilst preparing the solution.
Best regards,
Franz
rherz
Hi there,
As far as I know, using dichromate is now illegal – so that tip isn’t particularly helpful.
The problem has since been sorted out – the black-and-white slides were actually only intended to allow me to take black-and-white photos without needing a darkroom. A film scanner now takes care of that, and I no longer have any hassle with developing (and the choice of film is suddenly huge).
Best regards,
Robert
cfb_de
Hello Robert,
Commercial use is prohibited in certain sectors (e.g. vehicle manufacturing). In non-commercial contexts, dichromates are subject to no restrictions whatsoever provided the user is competent; in commercial contexts, where they are permitted, they are subject to the usual regulations. The pharmaceutical industry still uses chromic anhydride and dichromates on a massive scale today.
And I actually prefer a dichromate bleach bath to that potassium permanganate business, where you never know how good the solution still is and the activity is far more pH-dependent. However, I can also buy dichromates and know how to handle and dispose of them.
Best regards,
Franz
rherz
Hi Franz,
So it’s illegal for me – and probably for most people – because I don’t have the necessary expertise. ;-)
Even if I were allowed to, I’d prefer the safer option – the best chemical waste is the kind that isn’t produced in the first place – and if it has to be produced, then the less harmful sort.
Best regards,
Robert
cfb_de
Hello Robert,
You can acquire the necessary expertise :-) For example, through the Chamber of Trades, at an adult education centre, or, as in my case, by studying chemistry.
However, if I consider photography against the backdrop of ‘life-threatening, environmentally polluting waste’, then one should really give it a miss in favour of Niepce’s asphalt plates. Most developers (apart from the vitamin C solutions) consist of sulphite, basic substances in whatever form, and teratogenic, mutagenic, carcinogenic, and cancer-causing substances. If I were a scaredy-cat, I wouldn’t pour that stuff on my fingers and would only stand in the darkroom wearing full protective gear.
But when I look at the old master St. Ansel, the story looks quite different. *He* has certainly faffed about endlessly and has seen the demise of many a fine photographer: at a ripe old age.
When it comes to chemicals, I therefore believe that one should know what one is doing and take the appropriate safety precautions accordingly. And then, all too often, the solution with the lower toxicity is also the one with the most complex disposal process. For example, while copper sulphate is less toxic than chromates, it is usually disposed of untreated by amateurs via the toilet. Chromates, however, are taken to the hazardous waste collection point by themselves. Copper sulphate in the toilet is by no means harmless biologically, whereas chromium waste in the hazardous waste collection point does not end up in the environment so quickly.
Best regards,
Franz
Gast
Well, I can only agree with what Alex said – I’ve achieved very good results with these settings.
Has anyone had any experience with extending the clearing time to prevent brown tints in slides?
Is it theoretically possible to clear for too long?
