All rolls were stored and shot in similar conditions.
I plan on running a test with blank rolls this wknd to see what happens.
I've a shoot on Monday that will result in 30 or so rolls, so I'm hoping to get it figured out by then.
Oh, and both my tanks, new and old, have always leaked a bit at the edge of the lid during agitation. Nothing out of the ordinary though.
Last edited by GraemeMitchell; 12-06-2008 at 08:41 PM. Click to view previous post history.
Could you have shot over a previously exposed roll (double exposed)
I know exactly what caused these marks!
STATIC ELECTRICITY! Each one of those dots is a static discharge.
This usually happens when you are unspooling the roll. It can also occur if you rewind the film too quickly. If your climate is very dry or you have taken the film out of a very dry fridge on top of it being dry, this will happen.
We see this from time to time.
When we have clients that have been to a very dry place we have to be very careful unspooling the rolls. Denver is a very dry place so we also keep a humidifier in the darkrooms when the humidity gets to a certain level. We used to be in NYC, ill bet you have old radiator heat...
Last edited by dr5chrome; 02-17-2007 at 03:25 AM. Click to view previous post history.
Originally Posted by dr5chrome
Good one. I was starting to think of in camera problem and not a development issue due to the noticeable patterns. I've seen dots in a small area from static but not a length of a roll.
This is funny, I'd just called a very knowledgable person at a good lab here, and he came to the same conclusion. I told him it wasn't likely b/c I shoot with my F5 on silent/slow mode, but, I never even thought of the rewinding process (fast), duh.
Originally Posted by dr5chrome
So ways to avoid this assuming I can't shoot in humidified rooms. Shoot on slow modes, rewind manually, unspool the film slowly.
Now I'm paranoid.
You're correct about the radiator heater too.
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Oh, and this is temp related too, right? So I'd probably be safe shooting and rewinding fast if I was in a heated studio...right?
If it isn't static electricity, then the only other item I can think of would be your changing bag you use for loading film into your reels and tank.
Thiis problem is not due to air bells. The density with air bells is lower, not higher. I agree with George on this.
The regularity and spacing of the dark spots is what bothers me. I cannot think of anything that would cause it. Most everything I think of would cause irregular defects.
Therefore, I would hazard a guess that this is some sort of manufacturing defect. Although, I would hasten to add it must be a rare one. I have never seen this before. It looks as if someone ran a roller with a regularly spaced set of teeth down the film, and it was about 1/4" wide or so. This would have caused a sort of pressure sensitization defect akin to the little half moons you see if you kink film.
You might want to check and see if the film all came from the same batch. If it did not, then it probably isn't a manufacturing defect, but if it did come from the same batch and you don't get it on film from another batch, then it is a manufacturing defect of some sort.
You can try developing a roll that has not gone through your camera, and if it shows the defect, then it raises the probablility of being a manufacturing defect of some sort. That would help you when you return it. Kodak will replace all of the film in that case.
I'm unable to check if they're from the same batch now, but I suspect so, being purchased at once from BH (50 rolls).
I just did a test:
Shot one roll like the firsts, using motor rewind and unspooling it quickly: the marks repeated. Though not terribly and only on the leader and first frame.
Shot another roll manually rewinding and unspooling the film slowly: no marks.
This is the last I have from that 50 rolls of film.
Now I need to figure out if it is static if it is happening during rewind/shooting or when. I'd like/need to be able to shoot and rewind fast w/o worrying about this. Unspooling I am able to take time with.
Static electricity is generally darker and not square shaped, but I wouldn't rule it out altogether.
The discharge is in the UV range and film is rather sensitive to it, so it is dark. Because it moves like a lightning bolt, it normally has a linear or jagged appearance. It would also not be so uniform nor distributed at the center of the negatives, it would be random.
Again, I'm not ruling it out, but I do feel that is not likely. I have never seen static discharge like that. If it is static discharge though it still poses the question of why it is happening. It implies something wrong with the rewind or the casette.