Film surface damagegreenspun.com : LUSENET : Large format photography : One Thread
I notice that on many of my transparencies there are clusters of tiny dots of a color varying from very blue to almost white. Have any of you had the same problems ? I always assumed this was caused by dust particules, and vibrations due to mechanical transportation. However, it is not entirely clear to me why this would make dots rather than lines. A fuji film rep once mentionned a rather complicated physical process (that I don't remember well) which would occur in low-humidity conditions, like in the desert, but I've had the same problem in Alaska, and some of the film which suffered this kind of damage was subjected to mechanical transportation only by plane. So my second question is, do you know the exact cause of the problem, and how to avoid it ? Thanks.
-- Q.-Tuan Luong (firstname.lastname@example.org), August 03, 2001
Tuan, I've not seen this problem, but wonder whether it might be the result of some particles released when you cut your 8x10 sheets down to 5x7. Has it been evident on factory packaged 5x7 sheets also?
-- Sal Santamaura (email@example.com), August 03, 2001.
Tuan: Would you say a little more about these dots? What size? How many dots in a cluster? All dots the same size? Any pattern to the dots in a cluster? How many clusters on a sheet? Everywhere on a sheet, or predominently in certain locations? Does almost white mean light blue? A good puzzle!! Good luck. Dave
-- David Lewis (firstname.lastname@example.org), August 03, 2001.
Fungus/ mold in early stage?
-- Jim Galli (email@example.com), August 04, 2001.
I had not given more details because I thought it was a common problem that someone would recognize from the short description. I'll try to get a scan in the future. Each of the dots is pinhole size, barely visible with the naked eye. In a cluster, each dot seems to be approximatively the same size (difficult to tell because they are all so small). The number varies from a half-dozen to maybe a few hundreds (the thought of the time spent clonning them out makes me tired). They are all aligned along a path. Sometimes this path is a short line segement, sometimes a random walk. In most cases, there is only one or a few clusters on a given sheet of film, and the location appears totally random. I have not used factory packaged film for several years (after Fuji discountinued 5x7 in the states). I did notice the problem was much less common with factory packaged film, but it did occur on a few sheets at least. The color blue, I've been told, is what you get if you scratch your E6 film prior to processing.
-- Q.-Tuan Luong (firstname.lastname@example.org), August 06, 2001.
Tuan, this is a stab in the dark but are you using an ionizer when you cut or load your film? I say this because it sounds like it's something in the air falling onto your film.
-- Dave Anton (email@example.com), August 13, 2001.