How Critical is Dust Removal from Slides?

I have seen a lot of discussion regarding dust removal from slide

transparencies, both pre-scanning and during the scanning process using

technology like ICE and Dust Brush, etc. I haven't seen the results of an ICE

scanned slide, but when using the Dimage Scan Dual IV scanner Auto Dust Brush I

can't tell any difference in the dust removal. I have been enlarging my scans

to 100% in Photoshop Elements(pixel-sized image) and then cloning out the dust

specks and scratches which is a very time consuming process. I would like to

know how critical this dust removal is with respect to an image that would be

sold to an agency for enlargement and publication? Would the dust specks from

an untouched image be evident when enlarged to page size(approximately 8" x

10") in a standard periodical? Would the the image quality be acceptable to a

photobuyer without retouching? If not, what did photobuyers do "pre-Photoshop

days"?

Lon, I can't comment on commercial acceptability, but to expedite small diamter dust cleanup in Photoshop, particularly in areas with complex patterns where healing brush or clone stamp is difficult to use, you might try the following with the History Brush:

 

1. Open image. Open History pallet, and adjust it's settings to allow non-linear history. Verify an initial history snapshot has been made (it should be, this is PS default).

 

2. Apply Dust & Scratch filter with radius 5 and threshold 0 (Image should become very softened). Take a second snapshot in history pallet (camera icon at bottom).

 

3. Set you current state back to beginning by clicking on the right side of the initial snapshot (at top of history pallet).

 

4. Set History Brush to source from the second, D&S treated snapshot (small square at left side of second snapshot).

 

5. Set current tool to History Brush, set mode to "lighten" for dark dust (typical with slides) or "darken" (typical with inversed scans) or "normal", for the occasional mixed marks. Set diameter around 20, and apply the History brush. Just dab, don't do strokes, or it will soften too large an area and become obvious.

 

Only use this for small diameter dust, particularly overlaying patterns and fine detail. Or for cleanup after using healing brush or clone stamp.

 

BTW, if you're considering a scanner with ICE, it *is* worth it. Still won't be perfect by any means, but it will reduce your clean up work considerably.

I have scanned thousands of slides on my Konica Minolta Dual scan IV.

I found that the best approach to the dust, is to get a can of compressed air, and blow off as much of the dust as possible prior to scanning. I do not use the Minolta dust removal software/filter. If dust is present in the scanned slide, I resort to Photoshop to clean the slide up. Similiar to Mendel suggestion above, requires alot of time if you are doing many slides.

 

Get as much of the dust off prior to scanning.

 

Bob

Lon: Below I'm including information re. dust removal that I posted last year in response to a post entitled: "That Ol' Devil Called Dust" (May 10 2007 Digital Darkroom forum). The method I discuss below was one I used for many years and will help you before you scan your slides, because the best way to get rid of dust is to remove as much as possible before scanning.:

 

Steve Sharf, May 11, 2007; 11:56 a.m.

 

: "I spent many years doing darkroom work with large format negatives. Regardless of how diligent I was in keeping my environment dust free, and I was, I still had to control dust on my negatives every time I made an enlargement. One device that I quite liked was a rather simple small hand held static controller, (unfortunately I havent seen them for sale for a while though they still may be out there)that was a device that looked sort of like a hand held stapler that, when you squeezed it together, emitted an anti static charge out a small hole. These devices were made to remove static from old LP records but worked on anything that you aimed it at. For negatives coming from plastic sleeves, it worked very well. I would aim the device , neutralize the static, and then blow off the now loose dust with a blower. Sorry I dont remember the name of this thing but I would inquire at a high end stereo place where they still sell turntables. It only cost me maybe $15 or $20 about 20 years back. Good luck."

 

Hope you can still find these devices Lon as they are great. Good luck.

 

Steve

Any agency worth a light won't accept any scan where dust and scratches are visible at 100%. Stock Agencies - or at least the bigger/better players- look for quite large images -50MB or more- and this shows up blemishes quite clearly, so it needs to be clean. How you get there is generally up to you, but your editing must also not be visible at 100%. Personally I find Ice quite effective, and I certainly find manual spotting less than fascinating over a hundred image submission.

 

Before Photoshop, the stock industry worked on the basis that the photographer left the original with the Agency, and the Agency made dupes which were satisfactory for most purposes. Exceptionally, a customer might have been given an original.

 

I think you'd like us to say that a bit of dust etc is OK and that end-users are happy to clean according to their needs. Well this just isn't the way things work I'm afraid- though whatever arrangement you can reach when selling direct to end users (rather than through one of the bigger Agencies)is down to you.

Lon: No museums, publishers, or any other professional organizations I know of will accept dusty or dirty images. From working with slides, my understanding is that you can never physically remove every mote of dust from a slide, no matter how carefully you clean. The standard process where I work is to dust off the slide with compressed air, clean off dirt as necessary, and then take care of any residual matter using ICE or Photoshop. We edit at 200% to make sure our images look as good magnified or enlarged as they do normally. Yes, cleaning can be a pain, but it results in top-quality images and is ultimately worth the effort.

Everyone agrees, you need to remove any dust/scratch you can see at 100%.

 

And of course you want to do this with the least possible distortion to the scanned image. My workflow is:

 

1. Blow. This is the only form of dust removal that has no deleterious effect on the image itself, so do it. Aggressively.

 

2. Digital ICE etc. On the right kinds of film, the infrared-based cleaners are quite good at removing the crap with almost imperceptible changes to the underlying image.

 

3. Manual retouch. I use the clone tool with a soft-edged brush 2x as wide as the dust I am retouching. Like Megan I do this at 2x magnification, sometimes 4x if it is in an area of detail that I really want to preserve.

 

I NEVER use a software dust and scratch filter that goes to work on the whole image. No matter what cute layer tricks are used, to me the degradation of the underlying image is always unacceptable.