Causes for Scratched Negatives?

<p>I have shot three rolls film, 2 BW and 1 color with my IIIc. Both of the BW negatives show very thin scratches on the top half of the negative, presented as longitudinal lines that carry across the entire roll. The color roll does not have any of these lines present.</p>

<p>To my eyes it does not appear to be a problem with the curtain.</p>

<p>I am using the same photo processor (they actually send it out to be developed by machine). Each roll was developed about a week apart. The BW is developed on a different machine than the color film.</p>

<p>Is there a way for me to tell if the film is getting scratched by the camera or by the processor?</p>

<p>(FWIW, I’m not setup to develop these at home)</p>

<p>Thanks,<br>

Jim</p>

<p>I forgot to mention, the lines are in the precise same location on both rolls of BW. --Thanks</p>

<p>Jim, in the past I used to experience similar problem with some rolls of film used in my MP. The line would always be horizontal running along the entire length of the roll. It appeared that the film was scratched either during winding (in camera) or during the development process. I haven't seen that problem for a while and I decided that it must have been a problem with the lab I used at the time, although I did suspect the camera too. Now that you mentioned I am thinking once again that it could be my camera. Anyway, if someone has a good answer it would be nice to hear it. Thanks</p>

<p>Since the lines appeared on the B&W only, I would think that the problem is in the processing. Most large labs have dedicated machines for B&W and color due to the different chemistry, explaining why you would get them with B&W, but not color. If it was a problem with the camera, it would appear on both types of film.</p>

<p>Jim - if you are bulk loading your B&W film, it could be either the light shields on the bulk loader or the cassettes. Otherwise, I would be inclined to agree that the problem is probably with the machine processing the B&W films.</p>

<p>Have them process an unexposed roll of film. If it has scratches -- it's their fault.</p>

 

<p>You have the answer here: "If it was a problem with the camera, it would appear on both types of film."</p>

<p>Here's an example of what I am seeing. Let me ask, <em><strong>if</strong></em> it was my camera what would be causing it?<br>

Notice that there are some diagonal scratches on this image/roll. Would that also be consistant with the processor?</p>

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<p>It's consistent with a dirty machine at a lab that does not handle your film with a lot of care. Or at least the film has not been treated well in this particular case. Since the scratch is along the whole negative, it is consistent with a roller-transport type of processing machine. These need to be kept very clean, as the film is basically dragged all the way through it, so if there is grit or a burr along the film path, it will cause a scratch like this. It could also be from the scanner if it is a roller transport scanner. More likely to be during processing though, as the film is more delicate when it is wet. The diagonal scratch would be from general handling, either during the cutting, sleeving or scanning. This could be from the lab, or from you, depending on what kind of work you did. </p>

<p>I would suspect the pressure plate on the back of the camera that keeps the film flat against the film plane. Some films are thicker than others and that might be why you see it with some rolls and not others. </p>

<p>I found the lab that does the developing and they use a dip-and-dunk method rather than roller-type, per their website. This is contrary to what I was told yesterday, but this new information seems to check out.</p>

<p>At this point it appears related to my camera or to how I load it. I was told that the emulsion on color is thinner than the emulsion on BW, which is consistant with what Michael is saying above.</p>

<p>If this is a problem with the pressure plate, is there anything I can do on loading to prevent the scratches? Is this more likely something what will have to be fixed on my camera?</p>

<p>Thanks,<br>

Jim</p>

 

<p>Check the film gates and the pressure plate for any burrs or anything rough. The Nikon pressure plates used to have holes in them, where if a piece of dust or sand got in the hole, it would scratch the heck out of the film. Since the scratch is white and not black in the print, I would suspect its not the emulsion side of the film, and there for its the pressure plate. Good Luck. </p>

<p>Thanks, Michael. I'll run one more roll through and then take it to a Leica tech. A non-Leica tech looked at it today and there are no burrs on any of the visible portions. The Leica tech will be able to remove the main unit from the housing to check. Thanks, everyone, for your help!!!</p>