Scanning thousands of old slides?

Film scanners are very good, but are also very slow. You may do well to average 10 slides per hour overall, so thousands of slides may take many months, or you may never finish. The Nikon 5000 film scanner does have its SF-210 Auto Slide Feeder accessory ($450) for overnight runs of 50 slides, if it doesn't jam. It was one thing to sit down one evening with one roll of slides, but something entirely different to be facing a few thousand old slides.

I did scan the better candidates, but I kept putting off all notions of scanning all of them. What I finally did was to use a slide copy attachment on a digital camera. Then hundreds, even a thousand slides per day is possible and was accomplished, including some post-processing. The camera is extremely fast. Perhaps this method is rushed, but the job does not happen otherwise. The results seem plenty good enough, assuming the slides are decently exposed, and clean and in good condition. I'd guess you will likely resample all of them smaller to computer or TV screen size anyway. If you want to be able to view all your old slides again, then a digital camera is a very fast way to do it. I am really speaking of a DSLR with a good macro lens, but you will see below that there are other choices too.

A $50 Nikon ES-1 Slide Copying Attachment is shown, on a Nikon D70S DSLR with a 60mm f/2.8 D macro lens (which focuses to 1:1 enlargement). From the camera outward is the 60mm macro lens, BR-5 step-down ring, K5 extension tube, then the ES-1 copy adapter (all Nikon products).

This Nikon 60mm f/2.8 D AF macro lens is about $400, and Canon and Sigma have similar lenses. The ES-1 attaches to a 52 mm filter thread, so it should fit any brand of DSLR. My lens needs the Nikon BR-5 adapter, which is just a 62-52 mm filter step down ring (a nice one, with large knurled diameter). The ES-1 copy attachment is basically an empty tube or spacer. It is just a slide holder, and it has no optics in it. The macro lens does all of the optical work. The ES-1 was designed for film bodies to copy slides with a 55mm macro lens which focuses to 1:1.

However the problem is that for today's digital SLR with the 1.5 lens factor (smaller sensor size), we need more like 1:1.5 size now. Which means that the 1.5 sensor factor needs an additional extension in front of the lens so the ES-1 can be adjusted farther out to the 1:1.5 size. My 60mm Nikon AF Micro Nikkor f2.8 D lens needs a 20mm extra extension (added between lens and ES-1) to cover the full slide frame on the 1.5x DSLR. (NOTE: the newer 60mm f/2.8 AF-S lens has less working distance, so it may not need any extension??). I used the K5 tube above, which works great (it is a simple aluminum tube, 20mm long, with 52mm threads at each end). However, finding that extra extension is the problem. See more about the necessary extra tube extension for DSLR (not an easy problem).

If scanning these old slides is your only goal, and assuming you already have the DSLR, and can find an extension tube, you might compare the macro lens expense with a film scanner. It is not a film scanner of course, and a digital camera will not be suitable to copy color negative film, but it works for slides. The macro lens has many other photographic uses too - it has great value in its own right. The Nikon 60mm macro lens is excellent for any closeup work, and I'd assume the other similar lenses were great too. I predict the macro would quickly become your favorite lens.

This ES-1 setup works very well for scanning mounted slides quickly - like magic after you get the hang of it. Truly fantastic for speed. Maybe not truly optimum, not like a real film scanner, but not too far from it, and which seems more than good enough, enough quality and size for this purpose to recapture thousands of old slides. There are some pluses too, besides the great speed, the macro lens is awesome quality, and the camera has an anti-aliasing filter. Frankly, due to the months of work that would be required on a film scanner, this job went years without happening at all.

Above is a sample image copied from a 1990 35mm Kodachrome slide, using the ES-1 setup with the D70S. Click the image to see the full size 6 megapixel 3008x2000 pixel 900KB image file (however to see full size, you may have to turn off Automatic Image Resizing in your IE browser). Pixel dimensions are roughly equivalent to scanning at 2200 dpi (a 12 megapixel camera would compare to 3000 dpi). It was shot with skylight (basically holding the slide up to the window light), and the RAW file was set to Cloudy white balance. ISO 200, f/8, 1/20 second in A mode (skylight auto exposure varies with day and slide). This is a typical good slide, certainly not my worst, but not the best one either. More of my slides are marginal that I care to admit, but if you have decent slides, you can get good images this way too. If not decent, then it should reproduce that too. :)   Results are obviously good enough. And did I mention it is very fast?

Here is the same slide copied with a Canon A620 PowerShot compact camera (point&shoot) in its macro mode. No extra attachment was used - its macro mode gets this close if zoomed to wide-angle. Click the image to see the 7 megapixel 3072x2304 pixel 1000KB image file (compressed more, camera JPG file was 3.1MB). Pixel dimensions are roughly equivalent to scanning at 2500 dpi. This was a quickly kludged setup for the one image here. (My method: keep piling on stuff to solve the next immediate problem). The camera was on a tripod. The slide was literally standing up on edge on top of a light stand pole, held with a piece of tape. The slide was only about 1/2 inch from the lens, and lighted from the rear of course. This light was a 150 watt household tungsten lamp (possibly 2900K, but not a 3200K photo lamp) in a ten inch clampon utility reflector on a light stand (about 15 inches from slide), through a plastic tupperware tray (yet another light stand) covered with a white bedsheet to diffuse it sufficiently (this lighted area should be a couple of feet wide, the slide at 1/2 inch is a wide angle situation). Camera mode A at f/4 was set to Tungsten white balance. The JPG was a little blue, and was adjusted here with -Blue and +Red. Auto exposure was ISO 100 and 1/80 second (time delay shutter to let camera stop shaking). This camera takes 4:3 pictures, but the slide was 3:2, so the ends are cropped. The top edge ended up not quite cropped enough, due to the slight barrel distortion shown. A straight edge held to the top railing on the right shows a similar bow, which no one would notice. Considerable vignetting (dark corners). This is a pretty extreme situation for the little compact camera lens. Not sure you would actually want to try this, and I'm guessing maybe the closeup adapters below may be better than this case. I did feel the very strong need for a convenient slide holder. But it is still good to be able to see the old slides again, and the point is that many things are possible.

There are third party slide copier attachments on Ebay (search slide copier) that are designed to fit over the lens of both compact and DSLR cameras. I have no experience with these, but they are a slide holder and a +10 diopter closeup lens (an extremely strong magnifying glass in front of the camera lens). These copiers rely on the range of your zoom lens to size the enlargement right. Point&shoot cameras only have zoom lenses of course, but word on the street says you must use a zoom lens on a DSLR too, with this type of attachment. Amazon.com has some of these too, with a few user reviews on the Opteka brand (the Bower brand on Ebay looks like the same unit).

I have not seen these adapters (I only have my Nikon ES-1), but I would normally be skeptical that a closeup lens could keep the edges of the frame sharp, however the smaller digital sensor would be a strong plus here, using only the center of the field. I already had the good macro lens, so my strong bias was for the slide-holding adapter without any optics in it, assuming better quality results from the macro lens than from inexpensive optics. There is a large difference in the cost however, and perhaps most methods are good enough for this purpose.

You can use a flash or incandescent light source, and White Balance should match that source (not the slide subject). But I often just point it at the top part of the window for skylight (**NEVER** at the sun - which would damage your eyes), and use White Balance of "Shade", or sometimes "Cloudy" (extremely convenient, but slightly variable color as sky or day changes). Shooting RAW, you decide white balance later at the computer, with many possibilities which you can view and judge by eye. You can of course correct the original slide too. RAW is fantastic, its 12 bits have more range for this. The perceived advantage of skylight over flash is that focusing is bright. Using skylight, I use auto exposure in A mode at f/8 (f/8 seems optimum sharpness to me for this macro lens). My typical auto exposure varies from 1/10 to 1/4 second (both skylight and slides vary). Flash could be a much faster shutter, but the slide in the adapter is attached to the camera, so camera shake seems no problem.

For a compact camera, flash will NOT be an option. You must turn off the internal flash (film must be lighted from the rear). There is probably no way to sync an external flash, for sure not with auto exposure. But that still leaves skylight and tungsten light for compact cameras.

For a DSLR, TTL flash works great too, perhaps better. I used f/8 and the fastest sync speed shutter in Manual mode M. The SB-800 flash unit was in TTL mode on a hot shoe extension cord (SC-17, which is an older SC-28), pointed at the frosted front panel of the ES-1 from about three feet. This is a really good method. In TTL mode, the auto exposure is determined by automatically varying the flash power. The cord is short, so the flash is using extremely low power there, and for flash units that might overexpose that close, you could reflect it off of a white foam board for a greater overall path distance. The Nikon DSLR will focus in the dark when the SB-800 red assist light is pointing at the lens (you can see it there on the ES-1), but it was too dark for me to see the image in the viewfinder. So I added a desk lamp to help me see. Or still pointing it towards that window in daylight helps to see it too. Either way, you want the shutter speed fast, to hide the ambient light. Flash exposure is solely about aperture, so shutter speed does not matter, so long as it does not exceed the maximum sync speed of the shutter. Or using one fixed manual power level (manual mode on the flash) for all slides almost works too, since all the slides we keep are relatively the same correctness (don't laugh).

Either way, flash or skylight, auto or manual, it may still need minor individual tweaking later, and RAW provides a little range to do that. With regard to both exposure and cropping, it seems unreasonable to expect that they will all come out of the camera right.

About light meters: I normally use center-weighted metering, but cannot point it where I want on the slide, so I switched to Matrix metering mode for this. Light meters work by assuming any scene averages out to middle gray, which is true most of the time. So the meter reads the average intensity of the scene and tries to reproduce it as averaging middle gray. This is well and good at the original scene for the original exposure. It is also well and good for a well-exposed slide, it sees average middle gray, and it comes out averaged to middle gray. But it is a little different when seeing a black slide, or one burnt to clear film. The metering still attempts to make both come out as middle gray (auto exposure is longer for dark frames, and shorter for light frames). This is just what light meters do. So considerable tweaking may still be needed if you need to recreate the black or clear. You could choose to deal with this at time of copy exposure for the most fastidious result. I am normally as fastidious as anyone, but speaking of thousands of slides seems a little different. I don't keep many bad ones, so my choice was to ignore it and go quick and dirty, hoping RAW processing might be able to deal with it. I assumed I could always go back again if necessary, but I have not felt the need yet.

Most slides will autofocus fine, and autofocus is easily the best plan. Only a few won't focus (clear sky in that spot, which cannot be moved in the adapter), so then I just move the center focus zone over to where there are some edges to focus on. Or you could switch to Manual focus, and focus it by eye - which is easy, but it takes a few seconds. It seems important to remember to restore it to Auto focus for the next ones.

The ES-1 has sliding tubes which can move if pushed. If manual focus is used for all slides, focus must be rechecked often, because it can drift off, I think maybe due to pressure from loading the slide eventually shifting the tubes. But auto focus normally works great for almost all of them. However, this would seem an issue on the compact camera for the few slides that don't autofocus.

Once into the swing of things, I can shoot about 20 slides per minute (auto focus, auto exposure)... as fast as I can load them into the ES-1. This is the shortest part of the work. Play and learn the first day before starting the serious run. The ES-1 is not very helpful about controlling the position of the slide. You center it sideways by eye in the slot outside, which is easy to do, no big deal. I added a couple of layers of folded thick paper in the bottom of the slot to help center vertically. Initial alignment is not quite obvious, you crop it so the slide frame is not visible, but the viewfinder only shows about 95% of the frame anyway, etc, so it is hard to judge until you see results in the computer. Slight cropping will aid this effort, so all you worry about is getting it straight. Frankly, this location and cropping part is where the film scanner runs circles around us. But the camera's scan in a fraction of a second has much to be said for it too. Sufficient trial and error at first setup will learn about getting the right magnification size, and about centering it and rotating it straight, and then you can go very fast.

I shoot RAW, 2GB or 3GB at a time, and use Adobe Camera RAW (ACR) for post processing. ACR allows you to open all images at once (hundreds of them), and select all, and then do White Balance and saturation and CTRL-U auto processing in one immediate operation. This is fast. In fact, any operation (like cropping) can apply to multiple selected images when appropriate. But if not done this way, it is just a few more clicks on each one. I don't always sweat every little detail - remember, we are speaking of thousands of images. But I do look at each one (which is part of the reminiscing) and tweak the exposure processing on many, rotate those with portrait orientation, and maybe crop or straighten it. Which is just a few clicks on each, maybe 10 to 20 seconds (going fast), but on all those hundreds of images, this takes the vast majority of the time.

Even so, my best day was to copy and process 1000 slides (a hard days work - 6 hours or more). That would take at least several hard weeks of work if scanning... probably several months since there are other things to do. Admittedly, the scanning results might be better - maybe not my best work, but no reason to feel shame either. It did not include any dust processing - I did not even feel the need to brush the film. My film is stored well and the problem is mild. I can find some minor dust if I hunt, but it disappears when resampled to video screen size. Frankly, I think it may help that the slide did not sit out 30 minutes in the scanner slide tray. This digital camera method is rushed in comparison, but the images seem more than good enough to recover the memories in the old slides. No excuses, it sure beats the alternatives, of either many months of work, or no images to view. I am thrilled to have them digitized now for viewing.

RAW is much more than the ability to bypass JPG. FWIW, RAW really has no meaning from a scanner, which is already a RGB image, and we cannot use an image without gamma, and ordinary 16 bit TIF does all we could ever want. But cameras and their Bayer filters are a very different situation, plus it is the way to bypass 8 bit and JPG, but maybe the largest advantage is that the camera RAW tools are so powerful and convenient. The processed RAW files are my archive, and then Photoshop has its Batch processing with Actions to convert all the RAW files to smaller JPG copies for viewing, sized right for the situation. That may take an hour to resize a batch of 1000 images, but you can go watch TV. Frankly, I'm not sure how to work without it now. I do suspect this method is not for the faint of heart, because the closeup photography details may be slightly more difficult, and having the high quality macro lens seems a real benefit, and Photoshop ACR and Batch processing seem essential. Elements has ACR, but which does not include cropping and straightening (again, essential), nor the batch mode with Actions.

This was surely too chatty, sorry, but hopefully it is of help to someone. There are many details involved in all of this, and several choices, but a digital camera is in fact a good enough way to "scan" thousands of old slides quickly.

Copyright © 2007 by Wayne Fulton - All rights are reserved.