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weird sky blotches
Posted: Fri Mar 25, 2011 11:25 pm Etc/GMT-1+01:00
by dave_whatever
I've just been scanning some film and noticed on a couple of shots when looking at the scans at 100% that some have a weird sort of "pale dust" noticeable in areas of plain tone, mainly sky. Here is an example scanned at 1200dpi, shown at 100%, its on Velvia (see attachment). Anyone any idea what this might be? I've checked and its actually on the film itself, not an artefact of scanning. Looks generally like dust, but it can't be as its ligher. I will also add that this is developed at home in a jobo 25XX drum. I do wonder if its minor patches of overdevelopment, but its hard to imagine how this would come about in a rotary system. Any ideas?

- weirdsky.jpg (85.75 KiB) Viewed 6429 times
Re: weird sky blotches
Posted: Sat Mar 26, 2011 7:18 am Etc/GMT-1+01:00
by IanG
Looks like an agitation issue probably during First development, developer splashing on to film as the tanks filled.
Ian
Re: weird sky blotches
Posted: Sat Mar 26, 2011 8:02 am Etc/GMT-1+01:00
by dave_whatever
Yeah thats what it looks like to me, but I would have thought the whole central column/lighttrap that you pour through on the jobo tanks aught to stop this happening.
Re: weird sky blotches
Posted: Sat Mar 26, 2011 8:44 am Etc/GMT-1+01:00
by Ed Moss
I had a similar problem with an expert drum and negs, adding a pre wash stopped the blotches. It looks like it could be dev splashing onto the film as you pour it in.
Re: weird sky blotches
Posted: Sat Mar 26, 2011 11:25 pm Etc/GMT-1+01:00
by dave_whatever
That sounds like a good idea Ed, I'll probably give it a go. Luckily in a year of doing my own E6 I can only find 2 sheets with this on, so its not a massive problem but if I can improve the process then thats great.
Re: weird sky blotches
Posted: Sat Jan 21, 2012 8:51 pm Etc/GMT-1+01:00
by timparkin
dave_whatever wrote:That sounds like a good idea Ed, I'll probably give it a go. Luckily in a year of doing my own E6 I can only find 2 sheets with this on, so its not a massive problem but if I can improve the process then thats great.
Definitely looks like either splashing dev or water getting on the film before first dev added. It could also be air bubbles that form so it's always good to give the film a good tap after you've added the dev (not sure it is this as I would expect them to be darker than the rest of the sky)
Tim
Re: weird sky blotches
Posted: Sat Jan 21, 2012 9:47 pm Etc/GMT-1+01:00
by dave_whatever
Thanks for the input Tim (better late than never).
I generally do remember to tap the tank, and as you say you'd expect bubbles to give you underdevelopment not over. Since adding a pre-wash I've not noticed this problem happening again. I can't rule out water in there but I used to be fairly rigourous with drying the tank and reel.