Retouching long, straight scratches

<p>I shoot mostly B+W and scan in the film. I develop myself. No matter how careful I am throughout everything, once in a while I get a perfectly straight, mechanically induced scratch through partial or an entire roll. I can never seem to pinpoint exactly where it came from, but I know the possibilities are a piece of debris in the camera (I use many different cameras and keep them as clean as possible), loading the film onto the developing reel (I use the plastic reels and make sure they're clean, and load them gently) and possibly just a defect in the film or in the canister from the start. Seems like once in a while it's just unavoidable. Unfortunately scanning the film resolves so much detail that the slightest line will always appear in the image. For color and slide film I find the ICE feature works amazing at getting rid of everything unwanted. Naturally it doesn't work for silver halide.</p>

<p>Now, I'm very good at retouching dust and odd scratches here and there in Photoshop, without leaving a trace. But a perfectly straight line through an entire frame, I have difficulty. Usually end up with a "mushy" line if I just drag the healing brush along the whole scratch. Even when I try to work at it in separate sections, I still have a mushy band through the image. Does anyone have any tips for getting rid of this type of scratch?</p>

<p>Create a mask layer to apply the healing brush through?</p>

<p>What type of scanner do you use? I'm working my way through <a href="http://www.rockynook.com/book/91/scanning-negatives-and-slides%2C-2nd-edition.html">this book</a> at the moment, and one thing it suggests is, in cases where Digital ICE is not an option, the <a href="http://www.scanhancer.com">Scanhancer</a> gadget can be effective at diffusing the light in the scanner enough to improve the appearance of scratches, at a cost of a slight reduction in contrast and sharpness.</p>

 

<p>It may be the case though that your only solution is careful use of Photoshop's healing brush.</p>

<p>With Photoshop CS5 and later there is an option on the <strong>Spot Healing</strong> brush tool 'heal' process where you can check on "<strong>content-aware</strong>" in the menu bar - this also works with outlining with a tool like lasso, deleting, and then choosing 'content aware' in the fill process.<br /> It's sometimes simply magic. The algorithm that does this is so good that it's usually better than manual retouching. It's much better than what I have ever been able to see of the 'automatic noise reduction' processes like ICE or FATE. I turn those off and do manual 'spotting' with this tool for better results, especially with Kodachrome, but even with B&W negatives.</p>

<p>For me this works like a charm. Rarely you may need to touch up manually with the heal brush or copy tool. A good friend tells me that there is a similar option in GIMP.</p>

<p>Just for the mechanics of apply a brush along a straight scratch, say when using the healing brush:</p>

<p><alt>click to set your source<br>

click at the beginning of the scratch<br>

<shift>click at the end of the scratch</p>

<p>This will apply the healing in a straight line between the 2 previous points.</p>

<p>Thanks for all the ideas. ^ Interesting Mendel, I didn't know the healing brush had that feature. I done a similar method by making a line with the pen tool, and choosing stroke with the spot healing brush. A little different in behavior since it's the spot healing brush, but sometimes works very good. I have good luck using this method when the line is only across, say, a sky or something uniform. If it goes through a complex portion of a photo, especially if there are many intersecting straight lines, like a building with windows, it kind of creates a band of screwed up lines. I suspect there's not much you can do in that particular situation than spending the time to go at it carefully little by little.</p>

<p>JDM, I have amazing results using ICE with color negs and slides. I've had perfect looking scans from the worst condition negatives. Since it's hardware level, from what I understand it takes a second infrared scan which picks up physical anomalies, and maps them out without taking anything away from the actual image. But won't work with B+W because the infrared light reacts differently with the silver halide emulsion, and indeed I've tried it, and you get a mostly blank scan. I guess it actually perceives the silver halide as unwanted.</p>

<p>Just for the record, I think even the best of the routines cause at least a little loss of resolution. The infrared process is the best.</p>

<p>Here is an example of the worst result I've ever had - in this case from a Kodachrome slide. It is true that there no longer is any dust specks.<br>

Now I just clean them very carefully before scanning and do the minor amount of 'spotting' needed thereafter.</p>

<p>For the spot-healing brush, I repeat that the use of the <em>content-aware</em> feature makes the results MUCH better.</p><div></div>

<p>Try the patch tool, as well. It does a good job of removing long scratches in certain situations.</p>

<p>If it was a darkroom print, you'd dot in to break the line up into sections, then repeat for each section and subsection until the whole thing is filled. The point is that no two dots are exactly the same, so it looks natural. So I do the same thing on screen: I use the clone tool to copy from an area adjacent to where I'm going to dot, and I break the line up into sections, and so on. Takes a little while, but looks perfect. Make sure the edges of your dots are soft. (I'm a Mac user, so I'm doing all this in Aperture, not Photoshop.) I never use ICE.</p>