What do scratches on Film look like?

[Justin Marx]

Just got a student film I shot back, and 3/4's of the way through the roll there are 4 semi wavy blue lines from the top to the bottom. Are those scratches? Why so many lines? Could this be a problem with the processing/transfer?

I attached a photo.. I turned up the contrast so you can see the lines..

 

Thank you for your help!!

[Rik Andino]

Yeap them's scratches alright.

 

What you got there see can come from any of different places

Scratches can originate from the camera you used

Or maybe the projector...

 

And on some rare occasion they can come from the processing...

usually this isn't the case because labs are very careful when handling film

If 30% of the films they handled came back scratched they'd lose lotta business...

 

If you wanna know if they're from the camera or projector

Look at the negative and if it's got the same scratches as the workprint

Then it's the camera--& you'll have to get that camera checked out...

 

if the negative is clear of scratches but the workprint has them...

Then it's the projector...try to use another next time.

Anyways

 

 

Good Luck

[Stephen Williams]

Are those scratches? Why so many lines? Could this be a problem with the processing/transfer?

Thank you for your help!!

<{POST_SNAPBACK}>

 

IMHO it looks like negative scratches on the emulsion side of the film. You need to check the camera and magazine very carefully and try to recreate the problem with unexposed film.

 

Stephen

[John Pytlak RIP]

Emulsion-side pressure marks / scratches usually show as blue because the topmost imaging layer in the film is the blue sensitive layer. In a tungsten balance film, the blue layer also has to be the fastest, and the larger silver halide grains are most sensitive to undue pressure.

 

You should work with your lab in trying to identify the source of the scratches. For example, if you had film from different mags processed at the same time, and only the film from one mag has scratches, you have a clue. If ALL the film you had processed that day is scratched, the lab may be hearing the same concern from other customers.

[Dominic Case]

Blue scratches - definitely emulsion-side pressure marks on the negative, pre-development.

 

You say they are 3/4 of the way through the roll. Do they start at the beginning of a take, or anywhere else - or is it hard to tell where they start? Do they run right to the end of the roll? If you can see a definite start or end, it's often a useful clue to analyse what caused them. Are they on any other rolls? Did you use new stock or recans that may have been rewound?

 

If they are wavy, it points to a non-mechanical wind - maybe in the lab darkroom making up rolls prior to processing (though neg processors are usually the most careful film handlers of all for obvious reasons). But some parts of the processing machine could do that too.