Scanning and Dust Spots

[Peter]

I am just about being fed up with removing dust spots manually with PS for my scanned negatives. Could the digital darkroom gurus help me? I am using Dimage Scan Dual IV and its dust brush is next to useless. Short of buying a new scanner with ICE, is there a physical method to remove some of the dust spots on the negatives before scanning?

 

[Todd.Hanz]

Hardly a photoshop trick but you can use those anti static wipes before scanning, a cleaner neg is easier to spot.
Then I use the healing brush in photoshop CS. If the neg is scratched you can try the filter "dust and scratches" or "median" under the noise filter.
If the scratches are in an out of focus area you can apply a quick mask to the important area (like the face in a portrait), select inverse and either apply a gaussian blur or dust and scratches/median filter to it.
Most of the software that came with my dual scan IV is worthless, I adjust everything in PS now.

Good Luck!
Todd

 

[nwcanonman]

I try to make sure an carefully brush, then use canned air (like cleaning to lens) each slide before scanning.
I have a DS III, but never use Minolta's software. I use Vuescan, downloadable from the internet. No Digital Ice, but much better scans.

 

[jon_flanders]

I've had good luck using the smudge tool in The GIMP(available in a free download for Windows by the way).

I usually shrink the default circle the tool provides. Then go to view 200% to find the spots.

 

[jlw]

Re: Scanning and Dust Spots

I am just about being fed up with removing dust spots manually with PS for my scanned negatives. Could the digital darkroom gurus help me? I am using Dimage Scan Dual IV and its dust brush is next to useless. Short of buying a new scanner with ICE, is there a physical method to remove some of the dust spots on the negatives before scanning?

You didn't say what type of film you're scanning, but note that none of the ICE-type tools work with conventional black-and-white film!

The reason for that is that these tools use an infrared scan to distinguish between dust and actual details in the image. Chromogenic films (color films and b&w films that go through color-negative processing) form their images with clouds of dyes that are mostly transparent to infrared, while actual dust blocks infrared -- so, it's easy for the scanner to tell them apart.

Traditional b&w film, on the other hand, forms its image from metallic compounds that are almost completely infrared-opaque -- so there's no way for the scanner to tell whether that little black fleck is a dust speck or an important highlight area in your negative.

Having said all that, here's what I do:

-- I process my own b&w film whenever possible. Good labs are pretty careful about cleanliness, but I can be even more careful when I do it myself.

-- I try to scan the film as soon as possible after it's fully dry... the less time you wait, the less time for it to attract dust, have handling accidents, etc.

-- After loading the film strip into the scanner holder, I hold it at an angle under a desk lamp so the light shines across it. I examine both sides this way for dust, and then blast off any specks I see with canned air.

Even so, I still get some dust specks on my scans. In my experience, the best way to get rid of them is to select them and then run Photoshop's "Dust and Scratches" filter (under the Noise filters.) By adjusting the filter's two sliders, you usually can find a setting that will blot out the dust but preserve the area's grain structure.

Generally you can use the same slider settings for all scans from the same type of film, so I have saved custom actions with the settings I like best for Tri-X, Plus-X, P3200, etc. This lets me exterminate dust pretty quickly by scrolling around the whole scan at actual-pixel size, circling any dust specks with the lasso, then hitting the F-key I've defined for that film's Dust and Scratches settings.

It's still a bit tedious, though, and it still annoys me that dust specks that are gracefully suppressed by my enlarger's diffusion head are enhanced so luridly by my scanner!

 

[Todd.Hanz]

Here is an example (nothing extraordinay). Image on left has some dust specks when scanned into PS, Beacuse this image has a shallow depth of field I applied a quick mask to the in focus area only (face, arm of couch). I then selected inverse and applied the dust and scratches filter with a radius of 1, threshold 0. The effect removes the dust without effecting the image. There are other more complicated but more precise ways, I typically just use the healing brush and apply it to each spot.

Todd

 

[Peter]

Thank you so much guys for your invaluable advices. Just a question to Todd, is it not much easier to apply the dust and scratches filter to all the photo instead?

 

[aizan]

it take a bit of finesse, but you can use a copy of a suitable channel to modify and select all spots of dust at once. makes more sense to do that when there is a lot of dust.

 

[Kris]

...is it not much easier to apply the dust and scratches filter to all the photo instead?

You will loose small details in the area containing fine details. That's why Todd applies Quick Mask to the face, arm and sofa-arm area on his photo because those are where the photo is in sharp focus hence contains fine details.

Here, take a look at what happen if you apply Dust & Scratch filter to area with fine details.

 

[Todd.Hanz]

Kris hit it on the head!

Todd

 

[Doug]

Todd, nice example... and it really points up the way removing tiny nearly invisible dust spots can brighten up the overall effect.