film scratching

<p>Hi<br>

<br />I've trawled previous discussions of film scratches, but was seeking some advice.<br>

Just got back from holidays, and have processed both FP4, TriX, and HP5 film from different canisters for an ETRSi Bronica. There are scratches on the non-emulsion side, which are generally parallel with the film edge, though not precisely. They seem to very slightly move to the edges of the film, uniformly in one direction. Not on the emulsion side. And cross over the between frame spaces. They do not seem to show up in scans (though I only ran one test strip). So scratches on the non-emulsion side. Struck me as odd, as there's nothing mechanical the non-emulsion side comes in contact with. As said, experienced with different film holders.<br>

<br />Film loaded in a light tite bag, processed in a Patterson tank, with 10 sec/minute shaking, not swirling the film.<br>

Any ideas about what's going on. Any advice appreciated.<br>

Regards, Arthur (Apiarist1)</p>

<p>Is it one long scratch, or a series of scratches? If it's one long scratch, I'd look at the pressure plate. If it's a series of scratches, it's possible while you're loading the film onto the reels your finger or something is scratching it. I also use a darkbag and Patersons, and I'm always worried my fingers will somehow cause a scratch during reel loading. <br>

But I would look at the pressure plate as the most likely culprit.</p>

<blockquote>

<p>Struck me as odd, as there's nothing mechanical the non-emulsion side comes in contact with.</p>

</blockquote>

<p> <br>

Really! How about the backing plate, two or more rollers, and the next layer of film when winding? Check for dirt, stuck or binding rollers and possible damage on the film plate.</p>

<p>You did not specify 120 or 220 film. But I'll infer 120 due to its relative abundance, your processing tank, plus your stating (correctly for 120) that nothing comes in contact with the base of the film except its paper backing - which moves along with the film and thus protects this base from longitudinal scratching and most lateral scratching.<br>

So...my guess is that you need to evaluate your processing procedure - from the moment you've removed the paper backing through to the completely dry state of the film after washing. Pay particular attention to the interval from just after you remove the backing until the time the film is wound completely onto the developing reel - as you apparently do this in a changing bag, and as the film base might be vulnerable to contact with the changing bag during this interval. Another possible point of vulnerability would be if you squeegee your film prior to drying. At any rate...Good luck!</p>

<p>What was I thinking. There is a paper backing on 120 film.</p>

<p>If the scratches are near the edge, I would blame the processing tank, or any guide you use to load the reel. Plastic reals which load by twisting the ends tend to scratch the margins of the film, since it must be grabbed by a spring and pushed the entire length of the spiral until loaded.</p>

<p>Wire reels are much easier to load, once you have a little practice. The cupped metal guides tend to scratch the film, which is why I learned to load without using one.</p>

<p>Any reel will tend to mark the emulsion where it contacts the flanges during processing. These marks are on the emulsion side and generally rather wide, not easily mistaken for scratches.</p>

<p>Rubber squeegees are easily cleaned, and less likely to scratch than sponges, which trap dirt and film particles. Always use a fresh solution of Photoflow - just a drop or two in a tank full of distilled water. If you prefer water spots and streaks to the possibility of scratches, don't use a squeegee.</p>

<p>Squeegees are the main source for scratches... start not using them. If anyway you want to squeegee your film, simply use two gloved and rinsed fingers.</p>

<p>I also use Paterson reels, and I cannot think on a way to leave scratches if loaded properly (are there any other way to load them? :) At least mine (old ones) are made in quality smooth finished plastics.</p>