Scanning 35mm Transparencies - Any Help Welcome.

[Lancashire Lad]

Please forgive me if I should break any forum rules (This is my first proper post).
I am currently scanning some 35mm colour transparencies so that I can digitally archive them.
I am using an Epson Perfection 2400 flatbed scanner which has a built in slide/negative adaptor.
I generally scan each slide individually, at 48bit depth, 2400dpi, which gives a file size of about 5Mb per slide.
I have no problem with exposure, and the resolution on the finished scans easily allows for significant "enlargement" before pixellation becomes evident.
I never do any "in scanner" adjusting, leaving any tinkering with unsharp masking etc. for Photoshop (Elements 5), or Paintshop Pro.
My problem is that almost all of the scans look like they are slightly out of focus, and I cannot get sufficient post scan "sharpening" before noise starts appearing on the image.
The scanner works OK for flatbed copying of paper prints, and I am wondering if the problem is something to do with the scanner's focus - the plane of the transparency being lifted about 1mm above the glass by the slide mount. There is no facility for focus adjustment on the scanner.
I have tried removing the slides and laying them directly on the glass, using a microscope slide to keep them flat, but the scans become heavily Moire patterned and are much worse than when leaving them in their mounts.
Whilst I appreciate that my scanner is a compromise, and a dedicated slide scanner would almost certainly give better results, I cannot justify spending several hundred pounds on such a unit for the quantities of slides involved.
Am I being too optimistic on what I should be expecting, or can anyone suggest anything to improve matters?
(Apologies for such a long post).
Best regards
Mike.

[eeyore]

i suspect that you have identified the cause correctly - flat bed scanners are not great at scaning slides.

assuming you dont want to or cant afford to buy a slide scanner your next best option is to have the slides scanned by a service such as Lab 35 - a look in the back of a photomagazine such as amateur photographer will reveal many such services - mind you this is still not cheap.

if you have a dslr another option is to buy a slide copier which fits on the lens mount and essentially enables you to photograph a back lit slide - these are available for canon and nikon (but not for every other make) for arround 100 notes - the only other cost is your time in doing this as it is not the fastest process in the world.

If your time is vaulable you will be better off with a slide copying service.

[Lancashire Lad]

Thanks Eeyore.

I have only recently got back into photography in a big way, having now gone digital with a Nikon D80. (In years gone by I spent a fortune on Canon A1 gear and FD lenses which are now gathering dust and worth about as much as their scrap metal value).

If these lens mount adaptors are capable of giving sharp focus it might be worth giving one a try - I assume that the camera would be used on auto, with the adaptor pointed towards light source of known colour temperature?

Time is not so much of a problem, I would willingly put the effort in if it would give me the results. Even at £100.00 though, I would like some confidence, (preferably before laying out the dosh), that such a device would actually do the job satisfactorily.

Is anyone out there using one of these who could suggest a make/model, & give any feedback on performance?

Regards
Mike

[Jim Ford]

Originally Posted by Lancashire Lad

I assume that the camera would be used on auto, with the adaptor pointed towards light source of known colour temperature?

Shoot raw - you can then adjust the colour temperature to taste later.

Jim

[pressld2]

Originally Posted by Lancashire Lad

Time is not so much of a problem, I would willingly put the effort in if it would give me the results. Even at £100.00 though, I would like some confidence, (preferably before laying out the dosh), that such a device would actually do the job satisfactorily.

I have a Nikon mount slide-copier which I bought many years ago, long before going digital and used it a few times with my old FM cameras to make duplicates of some slides. It was always easy to tell which was the original and which the copy as there was a noticeable degradation in quality. For conversion to digital, my experience is that it's only a marginal improvement on using a flat-bed scanner with a slide adapter. About a year ago I decided I would have a go at digitising my old slides and dug the thing out of the loft. But after trying half a dozen or so I put it back in the loft as I still wasn't happy with the quality of the results.

While Jim is right that by shooting RAW you can adjust the white balance later, personally I wouldn't do that as it's just extending the amount of post-processing you have to do. In a situation like this you have complete control of the lighting and spending just a couple of minutes setting it up right before you start could save you hours of adjustments later. What I would do is blu-tack a sheet of white paper or card to the wall and photograph it using off-camera flash. You can then use this image to set a custom white balance in camera. Then provided you keep the camera and the flash gun in the same position relative to the card you can photograph all your slides at the "correct" white balance from the get go. I would still use RAW though in case I decided later that the "correct" white balance was not the one I wanted.

Dave P.

[Geoff F]

I have the Epson Perfection 3590 Scanner which also has an optional slide scanning function. It works reasonably well but scanned slides usually need some Unsharp Mask afterwards.

My advice is turn off all Auto settings and adjustments, then scan using sRGB colour or Adobe colour. Check with a Preview scan then manually do a Curves or Levels adjustment before scanning. Once you work out what the best correction is, it should be the same, approximately, for all scans using the same type of film. Different film makes will require different settings. ie Kodak is different from Fuji.

Scan at original size but with sufficient pixels to allow you to resize later. This will depend on your required finished size. Also, make sure that the film strip is the correct way up.

Exactly how are you sharpening your images after scanning. Correct use of Unsharp Mask is essential and it does take a bit of learning.

I found that a lot of my previously rejected film prints weren't actually that bad; it was just poor printing that spoilt them.

[Lancashire Lad]

Thanks gents,
It looks like i'm going to have to give this another coat of looking at - (as they say here in Lancashire).

Pressld2 (Dave P.),
Looks like your experience with these lens mount copiers did not provide adequate results. (I must admit, years ago I did try a similar gadget which I think was called the "Ohnar zoom reverser" which had the a T42 mount to adapt to my old FD mount Canons). I had completely forgotten about this until I saw Eeyore's reply, and was certainly unaware that they are now available for DSLR's. If I recall correctly, the results from the Ohnar were pretty dire.

Geoff F.
I think I must have tried every sharpening combination available.
including: -
sharpen, followed by sharpen again etc.
sharpen combined with sharpen more etc.
With unsharp mask I try to limit settings to 150%max with radius of 1.5 (I must admit I have tried quite a lot of different settings - usually followed by undo and try again).
In every case noise eventually starts appearing before the scanned slide is what to me would be acceptably sharp.
I could try to post an image to give you an idea, but almost all of them are underwater shots of reef fish, barracuda etc. taken with a Nikonos 5. I'm not sure whether the moderators would allow non British wildlife pics on the site).

Looks like it might be a case of either live with it, splash out on a dedicated slide scanner, or use Eeyore's suggestion of a professional lab.

Best regards
Mike.

[Geoff F]

Firstly, if you send an image to the Forum Gallery titled something like 'advice required about sharpening' then show it here as an example I can't see why it wouldn't be acceptable.

Secondly, if the problem is caused by sharpening, have you tried a bit of Threshold? Say, Amount 100; Radius 1; Threshold 1. Alternatively drop the radius to 0.5 and see if that helps.

If it is the background getting pixelated before the main image is sharp, this is what I frequent do. Draw a selection around the main subject (freehand selection tool), you don't have to be exact as long as you are just outside of the required area. Feather the selection (about 5 pixels) and use 1 level of Threshold with the Unsharp Mask settings.

But I think a lot of your problems are coming from the scanner settings not being absolutely correct. Are you using the 'Professional Mode' ? I found that I had to turn off the automatic continuous exposure correcting mode and do manual adjustments on the preview image. It takes a bit of time but the results are greatly improved.

What resolution are your final resized prints? You should be able to end up with 8 ins prints at 300 ppi without any problems.

It may be worth getting a few prints produced professionally to see if that makes a great difference. If so, you can then start working backwards to try to find out where you are going wrong. While you won't get full professional quality you should be able to get acceptable results with that equipment.

[Lancashire Lad]

Thanks Geoff F.





I always use "Professional Mode", and usually tweak the histogram settings, which automatically exits you from "full auto exposure" mode.

Once I've done any initial tweak on the preview scan, I then do the full scan - I've settled on 48bit depth, 4800dpi, as these settings allow for significant post scan cropping whilst still maintaining viable print sizing. - (Easily allows for A3 printing).

The final scans usually end up at around 6500 x 3900 pixels, at an average of 3MB, before any post scan cropping or image resizing.

I'm quite comfortable with the various scanner softaware options available for tweaking of the actual scan, (I'm using latest Vista drivers downloaded from Epson), and am generally pretty happy about what I can do in Paintshop Pro or Elements to play around with the final image. It is just the "soft" focussing issue that I'm not properly satisfied with.

I've uploaded these two images to give you an idea of what I am getting directly off the scanner. These are straight scans, with no post scan tweaking (warts and all). The only thing that I've done is resize to 1275 pixels wide to satisfy requirements for WAB's image archive.

Am I being too optimistic on what I should be expecting from this type of scanner?

Once again, thanks for your feedback - much appreciated.

Regards
Mike.

[Geoff F]

Obviously, you won't get professional perfection from a budget priced scanner (by professional standards this is budget equipment). I wonder if 48 bit depth is tending to pick up every bit of imperfection. Have you tried reducing to 24 bit to see what happens?

As for your examples. I have had a look at what appears to be the more difficult image and I think your sharpening technique may be accentuating the background noise. This is really a case for one of the more expensive sharpening programmes.

However, I have had a go with my suggestion for selecting and feathering (5 pixels) the main subject and just sharpening this part of the photo using standard Unsharp Mask. Radius 50; 3 pixels; 1 Threshold. This is the maximum I would use. I haven't done any other processing. A slight tweak with Curves etc might also help to enhance contrast.

See what you think. I reckon this is about as good as you are going to get. But, as I said previously, it may be worth getting some done professionally and comparing the results. Remember though; film, negs or slides, is still one of the best methods for archival storage of photographs and if kept under good conditions, should outlast CDs.