Gast
Hello photography community,
I’m having a problem with the development of my Foma black-and-white transparency.
I don’t know what’s causing it, but my slides are simply too dark.
I’m currently using a process—from Ilford, I think—involving a Bleach bath (potassium permanganate + sulphuric acid) and a fixing bath (sodium dis...)
I hope I exposed them correctly: five minutes from a distance of 30 cm using a 100W bulb.
Perhaps you could help me.
Kind regards, Chris
rherz
Hi Chris,
If the slides are all too dark, extend the initial development time. If you’ve performed the exposure correctly using a light meter or grey card and are keeping the temperature at 20 °C, a development time of around 12 minutes (30 seconds continuous, 15 seconds agitation) should be sufficient (using Fomadon LQR or Eukobrom 1 + 9 + 3 g/l sodium thiosulphate).
However, the bleaching time can easily be extended to 7 minutes. You can tell if the bleaching is insufficient by looking at the film edge – it should be clear.
If there’s a lack of double exposure, there will be bright spots in the shadows, usually bordered by slightly darker areas. (My problem!!!) How did you do the double exposure? Underwater or above water, light source – just post everything.
I hope that helps.
Best regards
Robert
Chris
I exposed the film as normal; I think my exposure meter, a Canon EOS 30, is working fine. I didn’t try anything out of the ordinary.
The initial development was carried out in Fomadon LQR, for ten minutes at 30-second intervals, and then agitated every three seconds. However, I noticed that the developer had expired in February 2003. Could this have had an effect? I stored it in a dry place away from direct sunlight.
I set the bleaching time to five minutes as per the instructions.
The base film doesn’t seem to be as clear as I’d hoped, particularly at the start.
According to the instructions, the stock solutions have a long shelf life. I mixed the Bleach bath itself an hour beforehand.
I re-exposed the film underwater with a gentle movement to prevent any shadows from the reel.
Many thanks, Chris
rherz
Hi Chris,
If I always used the built-in light meter, most of my photos would suffer from overexposure – so that’s probably not an option.
The developer turns increasingly yellow over time once it’s been opened; as long as it doesn’t look like clear apple juice, it shouldn’t be a problem – the fact that it’s already past its use-by date doesn’t matter at all.
With the bleach bath, the only time-sensitive part is actually dissolving the potassium permanganate – that takes up to two hours. Also make sure you don’t let the sediment at the bottom get into the storage bottle. It contains small brown particles (some sort of manganese compound – insoluble in water) which would otherwise get stuck in the film layer later on. Just prepare your Bleach bath last, then it’s guaranteed to be fresh! And keep the Bleach bath moving continuously; in other words, the tilting motion shouldn’t last longer than 2 seconds, and then the next one follows straight away. That keeps your forearm in shape ;-)
Try setting the times to 12 mins for initial development, 7 mins for bleaching and 6 mins for clearing, and have a look at the results – you’ve got the tips for correction now – and if it doesn’t work, just post again
Best regards
Robert
