Wiki: Slide digitizer

May 15, 2009 38 Replies

Not one-page-per-fiche, but the 13 x 11 ones? (or whatever they are - I don't remember for sure)

Text tends to be difficult to read if scanned at less than around 150dpi, so cramming 11 sheets' width into an inch of space really needs a minimum of 150 * 8.2 * 11 = 13,500dpi scanner resolution (not accounting for the gaps between sheets, and 8.2" being the width of an A4 sheet)

We did try sending a fiche off to a professional scanning place, and even their equipment just wouldn't handle it - the results were just a blurry mess :-(

Scanners do exist that should handle them OK, but they tend to cost upwards of 20k...

cheers

Jules

... which is trivially solved when post processing, if its indeed a problem. IMLE of it so far, it hasnt been yet.

NT

dot matrix printers produce so-so quality print at 72dpi. Microfiche gives much better print quality, but lets say 72dpi would be just usable to scan it with if scaled.

11x13 per frame means we need 720dpi, and the 8:1 scaling takes that upto about half a million dots per inch. So I cant see a 9600 dpi scanner having the remotest chance.

OTOH, as unlikely as it may sound... if you got the right lens my primitive machine might do the resolution. Trying to point the camera at the right image on each frame would be a hopeless task though.

NT

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Andy Champ saying something like:

Take your pick of virtually any of the desktop film-capable ones of recent years. Simply put your slides on the glass, do a preview scan and crop to size. Actually, if you're manually cropping, the slide holder could still be used. I have an Epson 3490 which would do that and it's 35mm only. My 4490 medium format will do that no problem. Of the current Epson models, even the basic V300 will do that.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember snipped-for-privacy@care2.com saying something like:

You must be easily satisfied. It's not trivial when you lose picture information you shouldn't be and don't have to be. Do you use a lens hood on your camera?

The film doesn't resolve anywhere near half a million dots to the inch so you have it wrong somewhere. As I said the scanner will record the grain on the common films with ease. I know they use ultra slow fine grain film but it isn't orders of magnitude better, maybe two or three times better. That may still push it beyond a 9600 scanner but not by much.

You need one of those £100 microscopes they had in lidl, they had a build in camera so you could picture it in sections and stitch them together.

>

My Epson 1680 pro flat bed can do quite a credible job of slides - I was surprised just how good it was (and that is comparing it against a Nikon LS-2000 dedicated film scanner).

First review I found says:

HP Scanjet 4890 Price: £165.00

The HP Scanjet 4890 comes in an initially impressive desktop-eating form factor.

Pros Generous film scanning area

Cons Disappointing scan quality; no hardware dust and scratch removal.

Andy

I didn't pay anywhere near that. I paid £122 IIRC. Not as cheap as the sj 5590 I got for £45 from a Staples sale.

It is rather large and appears to be real metal in places.

I would have to disagree.

It does scratch removal if you select it. It may or may not be in hardware, I never use it.

Now that I've tried it each way, I'll change the article to your suggestion. Both work but your method gives better saturation and more consistent backgrounds.

NT

but where?

show us your calculation then

I gather its actually not that hard to make a very simple microscope out of a camera. Something like 2 elements I think.

NT

Well 9600 dpi is ~370 ppmm. So a 9600 dpi scanner can resolve ~185 lpmm. Can you show me a microfiche film that can do better?

Put it another way.. if you shrink an A4 page down to 24x35 mm (approx) you get about 4400 x 6500 lines which will easily resolve 8 pt text IMO.

Its not hard to make a telescope out of two elements, however there is the problem of colour aberration, spherical aberration, coma, etc.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember snipped-for-privacy@care2.com saying something like:

That's it exactly. My question about the lens hood was an illustration of how much image quality is lost through an apparently trivial omission. I never used to bother much with hoods, but now I do.

In your copier, the room light bouncing around definitely reduces contrast, same as unwanted side light striking the front of a camera lens outdoors. Fully enclosing the copier would work best, and still be dead cheap.

yeah, i assumed post processing would take care of it easily, but it only partly does.

Fully enclosing would really interfere with slide changing though, and a decade or 2 of slides takes long enough already.

NT

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember snipped-for-privacy@care2.com saying something like:

An upside down box, painted black inside, just placed over the space between camera and slide holder. It'll certainly cut out nearly all the room light.

Have you seen those camera mounts you can buy? Search Froogle.com for ZOOM SLIDE DUPLICATOR. I was very tempted to buy one of these when I had several projects to do. Most of my customers only needed the slides scanned, so I could make them a photo montage video, so the resolution didn't need to be that high.

My method of choice was to borrow the slide projector from the library, set up my Canon Rebel 6.0MP camera on a tripod, and project the image onto a white piece of poster board. Then I would simply

*click* *click*. I got through 4000 slides in 5 days, working after my kids went to bed. Also, I went back into Photoshop and cropped them all to eliminate the rounded corners that most of them have. I did a batch levels after adjusting the first 10 or so, so I'd have an idea of how much to alter the photo.

Now I do small-quantity projects, and I want that Zoom thing. Has anyone tried one? BTW, I have started a blog about the woes and successes of 35mm slide scanner issues. Check it out. Please remember it's brand spankin' new, so it might take some time to build up significance.

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We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember ohsogroovy saying something like:

would you?

Ya, so? I still know a lot about scanning things. I've tried all kinds of methods, and I am still curious if anyone has tried those ZOOM camera attachment things before. Has anyone? Let me know if it's worth the money.

Thanks.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember ohsogroovy saying something like:

They work fine. Google 'ohner' as a make and you'll also find plenty on ebay.

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