View Full Version : Dust and Scratches

25-May-2015, 21:51
I've spent the last few days patiently cleaning some high resolution scans of 4x5 Portra.

They are full of scratches of varying degrees (from very faint hairlines to deep gouges) and full of lots of white spots all over the place.

My thinking is that dust on the negative during exposure will yield a black spot. Where as dust on the negative during processing will yield a white spot.

Does this sound correct?

Dust has become a major problem for me because I have neglected to follow basic dust mitigation strategies. Aside from my own issues, I think the lab that processes my film is also to blame.

It also doesn't help that I'm in India which seems to have the entire world's supply of dust!


25-May-2015, 23:47
Yes, that's correct.

26-May-2015, 04:14
What kind of dust management system do you have in your darkroom? Some workable solutions are a HEPA or electrostatic air cleaner, and electrostatic brushes, compressed air or vacuum.

Jim Jones
26-May-2015, 05:38
Raising the humidity in the darkroom with a teakettle may help. I always use distilled water, not tap water, for a final film rinse.

N Dhananjay
26-May-2015, 06:52
You are correct about diagnosing the way dust shows up. Electrostatic cleaners might help if you have a small room to keep dust free but I can appreciate the difficulty of doing that in India. The next alternative would be a mix of humidity and an electrostatic cleaner before you load or develop film.

But before doing all this, try wearing a cap when loading/developing and see if your problem disappears. It is surprising what a large source of dust the human head is, especially since it is held tipped over the sheet of film in intense concentration....

Cheers, DJ

Jim C.
26-May-2015, 12:03
Seems everyone missed the point that you send the film out to be processed,
if the spots are white then you need to approach the lab about quality control or find another one.

27-May-2015, 03:06
Thank you for all the great suggestions.

I do send my film to a lab and they are now officially fired!
Unfortunately, labs that process film (let alone 4x5) are a vanishing breed. I think there may be one other option for me in Delhi which probably isn't much better.

This leaves me with two alternatives, set up own min-lab with a Jobo or send my film out of the country for processing.

Both options are expensive and risky in their own ways. Not sure what to do...

Peter De Smidt
27-May-2015, 06:21
Do it yourself.