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Thread: Color negatives from lab have worm-like marks after scanning?

  1. #1

    Color negatives from lab have worm-like marks after scanning?

    I'm new to scanning. After getting back some 6x12 color negatives from a pro lab, I scanned them and began dust removal in Photoshop. I see a bunch of clearish, worm-like objects in many places on the film. They are large enough that I have to remove them to prevent them showing in the print.

    Also, I recently used Sam's Club (a big mistake) for some 120 film, and the negatives had the same worm-like objects and a great many pock like marks all over the place. They do not look like dust marks. More like damage marks. I'm spending hours on a single negative to clean them up.

    What causes these marks?

  2. #2

    Join Date
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    Re: Color negatives from lab have worm-like marks after scanning?

    Maybe the lab isn't filtering their water. Maybe it's bacterial contamination. Please post some images.

  3. #3

    Join Date
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    Re: Color negatives from lab have worm-like marks after scanning?

    Could be dust on the scanning surface or something like that? If it's in the same spot scan after scan then you know it's not the film.

  4. #4

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    Loupe the film first, but it sounds like a filthy scanner more than the film. Probably out of focus dust.

  5. #5
    ic-racer's Avatar
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    Re: Color negatives from lab have worm-like marks after scanning?

    Quote Originally Posted by Scott Page View Post
    I'm new to scanning. After getting back some 6x12 color negatives from a pro lab, I scanned them and began dust removal in Photoshop. I see a bunch of clearish, worm-like objects in many places on the film.
    Are you new to LF or MF photography? Unlike 35mm, there is no felt wiper for the film before the gate. Dust on the film will cause that. Make sure the film back and inside of the camera bellows are free from dust.

  6. #6

    Re: Color negatives from lab have worm-like marks after scanning?

    I might also add that infrared cleaning can seem to cause as many artifacts as it removes.

    It depends on the film used and the scanner settings.

    Some films don't work for infrared cleaning. Black and white is chief among them but Kodachrome doesn't work well, either. But, unless you're scanning old Kodachrome for preservation purposes, that point is pretty much moot.

    Second, the resolution setting on the scanner can affect performance. On my cheap scanner, I can't scan at much higher than 2400 dpi or else artifacts will show. Also, the "high/medium/low" setting for your IR cleaning can affect results. Only use the lowest setting that will do the job you need. Turning it up too high causes the computer to "fiddle" with the image too much, leaving artifacts where it "thought" there was dust but none really exists.

    Finally, scanner software has a lot to do with it, as well. Silverfast handles IR cleaning differently than ViewScan does. Each will produce different results under different conditions. (Hey, that's competition, right?) I have also found that the software bundled with the scanner produces still different results. I generally shy away from bundled software and go with ViewScan. (But that's my preference. YMMV.)

    I generally don't even use the IR clean feature on my scanner very often. I prefer to do the spotting by hand. I found a method that works pretty well and, with it, I can clean up a full frame, 2400 dpi scan of a 35mm negative in less than 15 minutes.

    I found this method in a book: "Photoshop for Photographers" by Martin Evening.
    Highly recommend this book. It concentrates on pictures and making them look good instead of using filters and tricks to make artsy-fartsy crap. It is my understanding that Evening was one of the guys on the team that created the original Photoshop. The guy knows his s#it.

    Anyhow, using any of the "Photoshop CS" versions (I use CS4):

    * Apply the Noise > Dust and Scratches filter to the whole image. Move the top "pixels" setting to the right until all the dust just disappears. Next, move the "threshold" setting to the right until the dust spots just seem to reappear then back off a click or two. When you have it the way you want, click "OK" to apply the filter.
    * The image will appear to be all "pasty" and blurry. That's okay.
    * Click "undo" and return the image to normal.
    * Go to the "history" panel. You'll see where you applied the dust and scratch filter then undid it. In the box at the left of the list, click to make the little "paintbrush" symbol appear. This sets the target for your "History Brush."
    * Activate your "History Brush" tool from the palate.
    * Look for the blending mode drop-down in the settings bar at the top of the screen.
    * If the marks in your picture are darker than the background, choose "Lighten" for your blending mode.
    * If the marks are lighter than your background, choose "Darken" for your blending mode.
    * Use your mouse and just paint over the marks. They'll almost completely disappear.
    * If you need to touch up any remaining artifacts, use your "Healing Brush" tool.

    The rationale for this method is thus:
    The Dust and Scratches filter blurs out the dust but it also blurs the rest of the picture. The History Brush allows you to undo that filter but keep it in memory where you can selectively apply the filter only to the spots that need it. The "Lighten" or "Darken" blending mode applies the fix ONLY to the pixes that need it, leaving the rest untouched. Finally, the Healing Brush (or the Spot Healing Brush) helps the "fixed" pixels blend into the rest of the picture better.

    As I said, I can clean up a full-frame scan of a 35mm negative in less than 15 minutes, often with better results than IR cleaning can.

    One final piece of advice: Get a graphics pen tablet. (Like a Wacom Bamboo tablet.)
    Whether you use Martin Evening's method to clean photos or not, it's an indispensable tool for any serious computer artist. Look around and you can pick up a decent one for less than $100.

    Like I said, I have tried all sorts of infrared cleaning and I have never found it to do as good a job as I can do with a pen tablet and Martin Evening's method. I often don't even bother with IR cleaning unless the picture is really dirty. Even then, I often spend just as much time cleaning up the artifacts that IR cleaning makes.

    I bet you'll be better off doing it by hand, as well.
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

    http://www.flickr.com/photos/randystankey/

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