Slide Digitizing -- Parkinson

Slide Digitizing A fast option by Tom Parkinson © May 2008

SUMMARY

This web page describes in detail a fast digitising process that allows you to digitise 400 to 600 slides an hour — plus one to one and a half hours to adjust, organise, name and file the results. It is based on using a projector with a stack loader and remote control. The lens is removed and a digital camera (with good quality lens and sensor) is pointed at the slide. The projector needs a translucent plastic “white slide” inserted between the condenser lens and the slide. Correct camera settings are vital. The results are fast with good to excellent quality but short of those available with professional film scanners. File size depends on the camera used. A section at the end of this web page has user questions and answers — edited by the writer. Yours comments and questions are welcome.

INTRODUCTION

I had been thinking of slide digitizing for years, semi retirement finally made it a more insistent thought that crystallised in the fall of 2007 when a friend invited a group of us to a retro slide dinner. We each brought a handful of local scenes from the past and an old American slide projector was brought out.

Painful memories. The screen had marks and a crease. Some slides were backwards, upside down, dusty or jammed in the recalcitrant stack loader. Slides from a carousel had to be laboriously inserted one-at-a-time. The corners were noticeably dimmer (vignetting). But there was fascinating content and many memories. Alarmingly there were signs of severely faded slides.

My memories were stuck in dusty boxes. Slides fresh from the processor were usually viewed once then filed away, rarely shown to others, rarely were prints made — remember those expensive, low-quality, dingy prints you got from slides? I estimated I had north of 25,000 slides and 5,000 negatives, taken from 1959 until I went digital in 1999 — forty years of trips, faces and field work, hidden away.

I spent several months researching options. The first thought was a commercial service. I could find nothing local at less than a dollar a slide, but an East Coast firm offered 47 cents apiece plus extras and postage — $15,000 and the risk of shipping loss did not appeal. (There were cheaper options with a US firm that sent your slides to India.) In any case the effort to organise, label and pack the slides, then organise and file the resulting scans is almost as much as the entire digitizing process described here.

I found only one product on the market practical for quantity scanning, the Nikon Coolscan 5000 ED Film Scanner and its associated SF-210 slide feeder. Price with tax was $1900. A Nikon discussion group complained about the habit of the overpriced $470 stack loader to jam and offered suggestions that involved cutting plastic or fixing springs. The killer was the time it took for the pre-scan, main scan and (when activated) the dust/scratch removal scan — three to four minutes per image. Essentially users stated that they loaded 40 slides and went to bed — hoping in the morning that nothing had jammed. This could take the rest of my life but the results were reportedly outstanding with multi-megabyte images and excellent colour bit depth and optical density.

I tried the old route of photographing an image projecting onto a screen and also onto ground glass. The keystoning was manageable but the quality was not acceptable to me — the optical quality of projector lenses is mediocre and vignetting was significant. On my first digital camera I had adapted an SLR slide duplicator that fitted on the front and, with flash illumination, produced excellent scans — but a tedious one slide at a time. If only I could adapt a stack loader to it? I took the lens out of my Sawyers projector and pointed my current camera into the lens opening. It took zooming to 140mm equivalent (4x) to fit the image — which was slightly out-of-focus and grossly overexposed and smeared. A white card behind the condenser lens fixed the exposure, and a taped-on close-up lens (from my Pentax SLR) fixed the focus, (the camera’s excellent macro feature does not work well with the lens zoomed out.) However the lighting was uneven at the corners and the Sawyers stack loader — with an arm that moved the slide in-and-out sideways — was unreliable.

As an electrical engineer I was taught about “fit-for-purpose”. If you need a 200-kilowatt motor to drive a rail-car you don’t specify an 800 kW one — rather a 250 kW to give an adequate margin. How would the slide scans be used? Not for a double-spread in National Geographic or a wall-sized poster; they would be viewed like all my other digital images mainly on a laptop computer with WXGA screen, 1280 x768 pixels, maybe more in the future. Any information over one megapixel is lost; the same story on a high definition digital projector. I had viewed some slides on a friend’s HD television. The results were stunning with each of the 1080 x 1920 pixels addressed but the total content used was only two megapixels. Allowing for some cropping and a margin, scanned files at four megapixels would be ample, would save on downloading and processing time, and on hard-drive storage space.

WARNING this fast digitization gives good to excellent results for casual viewing enjoyment, but if you are a professional or perfectionist, the modest file size, and lower colour depth and gamma are not for you.

MODIFYING THE PROJECTOR

When I used to teach I was provided with a Kodak Carousel projector and, when needed, the gravity-fed stack loader had always proved reliable except on very rare thick or warped slides. At the Vancouver Camera Swap Meet in November 2007 I bought an older model Carousel, without lens for $20, a Kodak stack-loader, new-in-box, for $10, and eBay produced three brand-name projector lamps for under $30 with tax and shipping.

A single screw opens the base of the projector and I cleaned the mirror, heat filter and condenser lens. Trial and error inserting card, paper and plastic “white slides” on either side of the condenser lens resulted mainly in disappointment as the white slides warped, gave uneven illumination or showed a grain pattern — partially visible on slides with open sky areas. The final success was a square of thick white opaque plastic cut from a file binder and inserted on the slide side of the condenser. It is about 8mm (1/3 of an inch) from the slide so small amounts of dust are completely out-of-focus — although I always clean the white slide with an air blast before each day’s digitizing. The auto focus feature of the projector did not like being without a lens and the motor ran continuously until I slipped a piece of card in front of the auto-focus sensor (bottom left of top image).

Do not put anything on the lamp side of the heat filter, it will melt and/or burn. Always unplug the projector before opening.

CAMERA SETTINGS

The next experiment was cameras and settings. My retired Canon Powershot A510 only produced 3.2 megapixels but had “fly-by-wire” capability. Plugged into the computer you could see the image, make adjustments and take the shot by clicking the “release” button. The image then transferred to the computer via USB 1.1. It sounded great and worked well but was far too slow — over one minute a slide, or longer depending on adjustments.

My current camera, a Canon Powershot A710 IS, has automatic and manual setting and a wide variety of presets. I started with the RAW file feature (requires downloading a BIOS add-on) thinking that the added colour depth would improve results. Wrong. After hours of manipulation I could not improve on the camera settings and the time to download, convert and adjust, even using the software’s “batch” feature was minutes not seconds per RAW image. So I was left to tweak the camera settings. First the colour balance. After dozens of attempts, including individual tweaking of custom channels, the best result was with the camera set on its standard “tungsten” setting and the 300-watt projector lamp on the low setting — with the bonus of extending lamp life. Later I found some films were overall blue or had aged and lost colour. Experimenting showed that it was easier to adjust colour afterwards not by making adjustments to the camera colour balance.

The next setting was the degree of amplification (ISO/ASA setting) and logically the best result should be with none — or the minimum the camera allows, as longer shutter speeds are not a problem on a tripod. I set the ISO to 80 and left it there. The camera set on “Auto” will revert to factory settings each time it is turned off and on. Using the “Program or Manual” setting retains all the “custom” adjustments so this was another no-brainer.

The A710, along with many Canon Powershots, has full manual adjustments for contrast, sharpness, saturation and colour for each channel — red, green and blue, plus an array of presets. I thought that low contrast and saturation would be best. Wrong again. None of the custom adjustments, or the “neutral” preset were satisfactory. The result I liked best was the “positive film” preset, which puts in a modest amount of sharpening, contrast and saturation. This sounded counter-intuitive as slides tended to be already contrasty and saturated, so I tried more adjustments — and ended back at the positive film preset. Your preferences may differ; Fuji Velvia slides did become oversaturated.

The 7.1 megapixels of the A710 (3072x2304) gave too large files. Setting the camera to a lower definition is unwise as there can be image degradation and time loss as the file is downsized. Also I did not want to tie up my main camera. Fortunately a trip to a local store found a discontinued Powershot A430 for $79. This had the necessary 4x zoom plus all the settings of the A710 IS that my tedious trialling had suggested were best. The A430’s 4 megapixels were just right, as was the lower ISO setting of 64. Ideally the best jpeg compression (superfine) should be used but again I found no difference so used the “Fine” setting that resulted in jpeg files about 1 megabyte in size.

The A430 had the same lens as my retired (with defective flash and display screen — it got wet) A510. Reviews confirmed that this was particularly sharp right into the corners, without colour fringing there and most importantly, at the 4x zoom position, almost no barrel or pincushion distortion. There will be some minor optical loss with the multicoated Pentax close-up lens and a cylinder of black card was inserted in the projector lens aperture to minimise any reflections — sort of a reverse lens hood. The A430 also has the advantage that the batteries and memory card go in a hinged door at the end without requiring removal from the ball and socket head.

Slides have a 3:2 aspect ratio while both cameras have the typical 4:3 ratio. (The slide mount masks the 24x36mm image by just below one millimetre all around.) I started taking the whole slide and batch-cropping the top and bottom (green rectangle). Then I tried cropping in the camera, moving the camera left-right for the best crop (red rectangle), pulling it out a few centimetres when I needed the entire image. I preferred this as many slides improved with the crop and I personally favour the 4:3 aspect ratio. Note the texture on the emulsion at the left of the slide image. This is why the infrared dust and scratch removal on many high-end scanners (ICE and others) cannot be used on Kodachrome or black and white film.

I experimented with manual focus and exposure, but found the nine-point AI auto focus best as it adjusted when the camera was moved in or out. Just occasionally the camera would not focus (some sunsets for example) and the solution was to swivel the camera horizontally, focus on the edge of the slide mount then adjust for the preferred crop while holding the shutter halfway down. Similarly the evaluative exposure setting worked best. This compensated for dark and light slides doing as good a job — or better — than I could do manually, including adjusting for large amounts of sky. The auto-exposure successfully brought up information lost in the underexposed shadows of many slides. Vertical shots were an exception, here the camera was not turned and so the auto position detector (a small gyroscope) was not activated and the intelligent “sky” exposure compensation did not work. Manually increasing the exposure for dark vertical slides with bright sky made a small improvement.

On the A710 I also tried the aperture control exposure mode (Av) to set the smallest aperture and so maximise the depth of field. It turned out to be unnecessary. There was sufficient depth, even at close-up, to cope with any slight unevenness in slide flatness — and with the white plastic “light table” the slides did not get hot enough to “pop”. The A430 does not have an Av mode. If your camera does then setting the smallest aperture may sound to be a good idea. On digicams this is rarely smaller than f/8 as the very small physical dimension of the aperture introduces optical aberrations due to diffraction interference effects. There is some evidence that, contrary to the normal optical wisdom that a lens is sharpest a couple of stops down from its maximum aperture, the best results on a consumer digicam may be with the lens at its widest aperture. (Exposures I got ranged from 1/10 to 1/1000 second at the 4x zoom maximum aperture of f/5.8.)

The 4 dioptre (23cm) close-up lens from a Pentax 110 SLR fitted snugly on the A430 lens snout with the assistance of one layer of electrical tape. It is essential that this close-up lens not be fitted tightly as the camera lens can retract unexpectedly if the battery dies or you accidentally turn the camera off — easily stripping the small plastic gears that move the lens. (I found out the hard way with a polarising filter on an earlier camera!)

So far the cameras had been mounted on a floor tripod with the projector at the edge of a table, but it was not convenient to make the small camera movements. A mini tripod worked better but finally I mounted the camera on a small plastic ball and socket head (from a security alarm sensor), glued to more of the white binder plastic. This moves easily sideways and backwards on the tabletop, allowing fast, minute adjustments — lower left picture. The projector can be raised as necessary and the camera inclined accordingly.

To speed things up and avoid vibration a cable release was necessary and this needed a custom setup, the release screwed into a nut and washer, covered with protective tape and held over the camera release with a heavy rubber band. (bottom-left) Ideally I should get an external power supply for the camera but did not as the rechargeable NiMH AA cells worked fine with one set handling as many as 600 pictures.

Now we were off to the races. Most of my slides are in metal or card boxes, 600 a time with little index tabs for subject and date. However I had about two thousand still in processing boxes, right, in 3-ring binder sleeves or projector trays. These were all moved into 600 slide boxes, all oriented horizontally in the process, taking care to avoid dust.

Recharged batteries, an empty memory card, and ready to put a stack of twenty to forty slides in the stack loader — but first the slides must all be horizontal. Fortunately the hinges on cardboard mounts and notches on most plastic mounts are easy to see and after a few trials it was easy to shuffle and rotate the slides without exposing the emulsion to dust.

Ideally each slide should be cleaned of dust. As the slides were stored in stacks dust was mainly on the end slides and I used a soft brush or can of air to clean these but otherwise let the slides be. Yes, occasionally some dust got recorded. If necessary that slide could be retrieved, cleaned and re-digitized. I have not done this but I could in the future for a selected few important images. At the moment the goal is to get through all the slides before there is more deterioration.

As I worked through the first two-hundred slides I became comfortable with moving the camera left-right-or-out for the preferred crop with my left hand, then pressing the cable release with my right hand, wait to hear the auto focus confirmation beep, then take the picture and press the projector remote for the next slide. After a time I was doing ten a minute, 400 to 600 an hour after allowing for the time to first orient each batch of slides, sip some tea or have a short smoke break. The slides are inserted completely opposite to the position for projection, right-way up with the side marked “towards the screen” away from the camera. As a result each batch would be photographed in reverse chronological order — for those slides that were in order, many were not, I think I must have dropped some boxes on the ground and just shovelled the slides back in. Order can be corrected later manually or by telling the organisation program (i.e. Picasa) to display in reverse.

The memory card held 500 images and then it was away to the laptop for the next step, downloading, adjusting and sorting into various folders — backing up to an external hard drive, occasionally to DVD disks. The laptop has a slot for SD cards and this is faster than a USB connection to get images onto the hard drive — less than one second apiece. I have a small macro (batch) program that does this move. (Not applicable to Macs) For those of you capable of adapting it to your settings, it is the following two lines saved as a batch text file: xxx.bat. Otherwise just use Windows Explorer or My Computer to drag and drop the slides into a new folder. (If you also hold the <shift> key down while you do this it will move nor copy the image files. i.e. it will delete them from the flash memory card.

move h:\Dcim\126Canon\*.* "C:\Documents and Settings\Owner\My Documents\My Pictures\DIGITIZE"

c:\Progra~1\Picasa2\Picasa2.exe "C:\Documents and Settings\Owner\My Documents\My Pictures\DIGITIZE"

BASIC ADJUSTMENTS

A fair minority of the slides could be improved in the computer by adjusting contrast and colour, very occasionally by sharpening. I had a wide range of program choices from the Canon Zoombrowser program, through Photoshop to free or open-source programs. My work computer used to have Photoshop on it but I never liked the complexity or slowness. I had bought a copy of Photoshop Elements for my laptop but it was also complex, bloated and slow, Adobe wanted full price for an upgrade and, like the other Adobe programs, it had poor support and the bad habit of starting behind the scenes when the computer is turned on, hogging memory and resources — not to mention the crashes. So I had an anti-Adobe period and replaced Elements with the Microsoft supported open-source Paint.Net and Adobe Acrobat with Foxit Reader and PDFCreator, leaving Flash as the only Adobe program left — set to off and activated only on demand — good riddance to some dancing web graphics. Paint.Net has good basics — layers, curves, levels, but no bells and whistles and no image organiser. It requires separate (free) plugins to open RAW files, do horizontal flips and a myriad of other things, from the useful to the bizarre. There is no Mac version.

For my organiser and most adjustments I used Google’s Picasa2. For a few slides I used good old Irfanview, my jpeg viewer of choice for years — a lean, mean program that pops up in a second, uses minimal resources and in its “add-ons” has a lossless jpeg converter for rotating images. It also has a lossless horizontal flip feature for the odd slide that was digitized backwards. As you work through the images fresh from the camera and find the same adjustments are being made over and over then the camera settings are not optimal. This proved not to be the case thanks to the days of trial and error with these settings.

Jpeg is a lossy compression format and it is important when making adjustments to only open and save each image file ONCE to avoid “artefacts” and loss of definition. Picasa makes this easy to do as it saves the changes in a separate file and when a complete folder of images has been adjusted you press the “save changes” button at the top of the folder thumbnails and all the changes are saved with the originals kept in a new sub-folder. (I subsequently deleted all these Originals sub-folders as they took up a great deal of hard-drive space.)

1: The first step is to reorient all vertical images. Hold down the <ctrl> key and sequentially click all thumbnails with the same sideways orientation. Then a single click on button 1 does the job. Repeat for images the other way around.

The next step is to examine the images one by one. If they look fine LEAVE THEM ALONE. You can waste hours fiddling with adjustments and my goal is to get good, even excellent—not perfect — results, rapidly. Generally you cannot fix a bad slide. I find that for every hour spent digitizing I spend about one and a half hours adjusting and organising images into folders.

2: If there are any black edges—for example you moved the camera back to cover the full image — or if you see an obvious improvement, crop with button 2.

3: Far too many of my shots were not straight and Picasa has one of the best setups I have found to rapidly correct this. It is fast and intuitive just remember to hit the “apply” button. Note that it automatically adjusts margins and so can crop part of the image away.

4: It may sound silly but if the image does not look quite right give the “I’m feeling lucky” button a try. This applies modest corrections to contrast and brightness and removes slight colour casts. As with most of Picasa the results are immediate and appear on the large image. No improvement? Use the undo button. There is no harm trying and no changes are made to the jpeg file until, at the end, you save changes made to the entire folder. (Picasa also lets you undo these image-by-image, reverting to the unchanged original without any jpeg conversion loss.)

5: Slides are notorious for blocked out shadows. Slide the Picasa’s fill button to reduce contrast and many times considerable detail shows up. But the result can look flat or washed out. It sounds unintuitive but try the “auto contrast” button (6), which restores contrast but retains most shadow detail. Washed out highlights? Over-exposed slides? There is nothing there to restore and nothing can be done about it—gone forever.

If these simple corrections are insufficient, the second Picasa tab “tuning” allows finer adjustments to contrast and brightness and the third tab “effects” has three useful buttons. One sharpens the image—go easy with this; another increases or decreases saturation—useful for some full-sun Kodachrome or Fuji Velvia slides where the camera settings are somewhat aggressive. The third useful button is “warmify” which can improve blue cast slides in a single click. Again try them, you can always undo. I estimate I “adjusted” about half the images.

Still not satisfied? Then right click the image and select “open with” which moves the image (without improvements made to date, including rotation, unless you save first) into the program of your choice, Photoshop say, or in my case, Paint.Net. But if you find yourself doing this more than rarely then this fast digitization is not for you. Invest the money and time in a professional scanner or out-source the work.

COLOUR ADJUSTMENTS

By now most of us are used to digital cameras with their Automatic Colour Balance that removes ambient colour casts. Not so with slide film, although some tungsten-balanced film was available, I always used daylight-balanced film. Artificial light puts out strong colour casts and on dull overcast days slides can have a heavy blue cast. Viewed on a screen in a dark room your eyes adjust for these casts — less so viewing in ambient light on a computer or television.

Fortunately most of my slides were taken on Kodachrome or, more recently on Agfa or Fuji emulsions, all of which have held their colours. Not so for many other emulsions, such as older Ektachrome, Ansco or 3M and a host of lesser films I tried. The occasional rolls of these have faded, some badly, sometimes only a single colour layer, often cyan, leaving a muddy brown image. These scans can be improved but as with highlight detail, if the colour is gone there is no reasonable way to restore it short of elaborate Photoshop work after creating layers for each colour. However Picasa proved good at removing the green colour cast from fluorescent and mercury lighting.

Henry Wilhelm’s 1993 book The Permanence and Care of Color Photographs is an interesting read about colour permanency—or rather the lack of it — and archiving. It is now available for a free download at http://www.wilhelm-research.com/book_toc.html. Wilhelm rates slide films for a 20% loss of the least stable image dye in accelerated dark fading tests at 144 deg. F and 45% relative humidity. The results were: all Kodachrome: 580 days, all Ektachrome: 225 days, Agfachrome 1000: 75 days; ScotchChrome: 45 days. Note that Kodachrome does fade badly when projected. I am not alarmist but the extent of deterioration in many of my non-Kodachrome slides is considerable and Wilhelm’s book confirmed my intent to digitize everything as rapidly as possible. All chemical-based colour prints and negatives, except Ilford Cibachrome, also suffer from deterioration in dark storage.

Picasa has four ways to adjust colour. First try the “auto-colour” button. If this does not look right undo and move to the “Tuning” tab and try the “Colour Temperature” slider, right for more red, left for more blue. Also on this tab the “Neutral Colour Picker” is very useful. It lets you select a white; black or grey part of the image and then removes the overall colour cast. On dull-day “blue” slides the “warmify” button on the “effects” tab can give good results. Take care when adjusting overall colour casts not to end up with pink or yellow skies. These look wrong, better to leave some colour cast on the rest of the image.

So far your images will be named in the camera as IMG_6754.jpg or similar. If you have locations and a date for a series of slides now is a good time to use the Picasa batch-renaming feature. Select the slides in a series then hit <F2> and type in a series name, for example “ParisOct1978-“ (The dash is important!). Picasa will then give all the selected images this name with sequential numbers after the dash: ParisOct1978-1; ParisOct1978-2, etc. If your slides are not in the order you want, use the Picasa thumbnail screen (library) to drag and drop them into your preferred order before renaming. (This is easier if you select the small thumbnail size.) They will then remain in this order. The final step is to organise the images into folders. Select a group of images from the Picasa thumbnails and drag and drop to the folder in the left-pane. No suitable directory or folder? Then right click and from the drop-down list select “Move to New Folder” and a prompt will pop up where you can type in a new folder name — after picking its location.

Now you have your images on the computer back them up. Hard drives can and do fail, computers get stolen. I back up to an external hard drive which filled-up requiring a larger one. These are cheap, $79 got a 160GB 2.5” drive and case that plugs into a USB port and does not require an external power supply. Periodically I burn all my images to a DVD disk — twice — one for storage at home the second set for storage off-site at a friend’s house.

CONCLUSION

I have just crossed the 15,000-slide mark, more than halfway there. It has brought tears and laughter as memories are revived of old friends and relatives, some now gone. There have been many pleasures of people and places long forgotten — and disappointments. Disappointments at all the images of my Grandfather’s 100th birthday badly faded because I used a high-speed film for indoor shots without flash—which I dislike. Dismay at how many of the images show camera shake or motion blur, or are out-of-focus or taken on inferior zoom lenses or have vignetted corners or excessive grain or were just plain bad images to start with—why did I take them? Yes I didn’t always have the best equipment and in the early years 10 ASA Kodachrome required long exposures.

My biggest regret was not doing this sooner, catching some images before they faded, enjoying the ease of viewing images on the computer, on demand, all in one place. I suppose I am lucky not to have lost any images to fire, theft or flood and the slides are as well preserved as practical—mainly in steel cases in a dark dry closet with temperatures in the range of 15 – 20º C. (Wilhelm recommends refrigeration!)

When I first explored a faster way of digitizing on the web two years ago I found little of help, hence the effort to write and post this report. I never thought I would be able to get through 400 – 600 slides in a two-hour session. Next year I will move to digitizing negatives and expect to buy a high-end flatbed scanner that will take 20-30 negatives in strips at one go—and look after the post processing and moving into individual jpegs.

Your comments are welcome to etb@telus.net — but not if you are trying to sell me services or tell me that fast and easy digitizing with a consumer digicam is futile. Life is short, I am achieving my intent and the originals are still there if I ever want 50 megabyte perfect digital images— but don’t count on it. Slides that have finally seen the light of day after thirty or forty years are unlikely ever to see it again — except for my professional transport slides which have been willed, along with funds, to two archives. The bottom line is that most of the four megapixel scans have more information than my original, often less than perfect, slides. I view the statements that you need 15 megapixels to equal 35mm film definition with scepticism. Lens tests suggest that typical single-focal-length lenses, stopped down, with fine grain slide film such as Kodachrome or Velvia rarely deliver more definition than 50 lines per mm at the centre, less at the corners. On a mounted 35mm frame, that is 1700 x 1100 lines — versus the Powershot’s 2272 x 1704 pixels. Using more megapixels on a small-sensor digicams can be counter-productive. http://www.6mpixel.org/en/ describes tests that show the optimal balance between image definition and noise on small-sensor digital cameras is around 6 megapixels and gives examples of 8 megapixel cameras with lower overall definition than 4 megapixel ones. The moral is not to chase the numbers but to evaluate the results.

Questions and my answers have been added at the bottom of this page.

© Tom Parkinson, Vancouver, British Columbia, Canada, May 2008

Tom Parkinson, B.Eng., C.Eng., P.Eng., MIET, is a Professional Electrical Engineer specialising in electric urban transport — trams/streetcars, trolleybuses, subways, and electric railway planning and technology. His company, Transport Consulting Limited, has clients in Canada and several Asian and European countries. He is a director of Transport 2000 BC; President of the Western Canada Photographic Historical Association and has a collection of over 600 35mm cameras. He is the author of three books, 150 technical papers and writes occasional articles on the history of 35mm rangefinder cameras. Sample: http://www3.telus.net/public/wcpha/GermanRFLeidorf.htm

Scan from Kodachrome 64

Ricoh KR-10 SLR, 1981

Tamron zoom at 240mm

Taken from my living room

(Downsized to about one quarter
the definition of original scan)

This report is posted as a public service. No representations are made or inferred as to the quality or satisfaction you might obtain from this fast digitizing method.

You are assumed to exercise common sense, such as unplugging the projector before you work on the innards and not attaching filters that are too heavy or tight fitting to a retractable lens.

Please do not link to this page as it is hosted on the free space provided by my ISP with strict traffic limits. Frequent access will unfortunately require it to be taken down.

Questions and Answers

Q: What is the resultant colour bit depth or optical density (Dmax)?

A: I don’t know, whatever is inherent in the Canon Powershot A430 camera. I just know that the results are very satisfactory to me. If you follow this route remember that your mileage may differ, your expectations may be different. While the process can be adapted for different projectors and cameras, you must be able to zoom into the image and, if your camera will not focus at that distance, you have to find a good close-up lens. The quality of the camera lens is very important; far too many digicams have fuzzy vignetted corners and colour fringing or spherical distortions around the edges.

Q: What about better quality available with a digital SLR?

A: If there is more information on your slides than four megapixels, yes, but corner definition may not be better and could be worse — and I doubt that you would find a 140mm lens small enough to fit inside the projector lens space. You would likely get better colour bit depth and better optical density and could use RAW files.

Q: Can I use a Bell and Howell Cube projector?

A: You can probably adapt this technique to any projector but make sure you are getting even lighting, particularly in the corners, even though with all slides horizontal you are not using the extreme corners. If your slides are all stored in slides trays, boxes or carousels then it makes sense and speeds things up adapting a projector that uses your storage type. Otherwise you need a projector with a stack loader or the process will take too much time.

Q: I use a Nikon Film Scanner and slide feeder and have not had jams. The results are outstanding.

A: You are lucky as the Nikon discussion group inferred that jams were common. I accept that a professional scanner will give better D-Max and a larger colour envelope but I cannot accept the minutes per slide scanning time with thousands of slides to get through.

Q: I have some Kodachromes that have deteriorated.

A: I have some slightly faded ones from my lecture slides but they have been projected hundreds of times. I also have a few rolls with a colour bias that I put down to processing errors — they were rolls not processed by Kodak. My first Kodachrome film was shot in Ceylon in 1959 and is perfect. It all points to the value of digitising now before there is more deterioration, Wilhelm shows that even Kodachrome suffers some dark storage dye loss.

Q: How are you avoiding the high contrast I get when copying slides?

A: I’m not sure but think that it is because of the amount of light that leaks around the slide in the projector. This acts like the “pre-flash” I used when I duplicated slides on film decades ago and serendipitously reduces contrast — partly restored by using the camera’s “positive” colour setting. On “average” slides the ensuing results are good but adjusting contrast is the most common fix needed on the images — about one in two.

Q: You were crazy spending so much effort and not using the RAW option or, at least, the lowest compression jpeg? I also disagree with you losing the “narrow” slide edges cropping from the 3:2 to 4:3 ratio

A: You have a point but the bottom line was that if the whole process was not fast enough I would not have the patience to digitize 25,000 slides. I just could not see any image improvement using RAW and it took four times as long per image. As a professional familiar with the workflow for RAW images your results may differ. As far as the effort, it will involve around 100 hours of time spread over six months — not exactly life changing. Some slides do have important material at the edges and I pull the camera out to cover the entire image — then crop to 3:2 on the computer — usually about one slide in a hundred.

Q: This all sounds too positive, there must have been some glitches?

A: Yes. The biggest annoyance after faded slides are those that have slipped out of their mounts (Kranzcolor below) and have to be delicately re-centered, then inserted manually in the projector. Occasionally I press the shutter release too fast and the image is not in focus. Also about one slide in a thousand comes out washed-out, without contrast. At first I put this down to pressing the shutter too fast before the auto-focus or auto-exposure had finished but it is not consistent and may just be a random in-camera processing error. Despite using the lower compression jpegs I have filled my hard drive requiring me to spend $90 on a new back-up drive — and move some files there. The number of DVDs I now have to burn to create an off-site backup is also a nuisance. After 9,999 slides the camera started repeating image numbers and, after learning the hard way, I now have to take care not to put two images with the same number in the same folder. (The newer one overwrites the old one — no warning.) Rare, but annoying, are a few slides with fungus growth and a few slides in glass mounts with Newton rings — interference lines where the glass touches the emulsion.

Q: I have a few hundred slides to digitize but I’m not handy. Can I buy your setup when you are done or pay you to adapt a projector?

A: Sorry no, I’m going to keep the setup and projectors are too heavy to ship around the continent. For so few slides I suggest using a commercial service — or just photograph the slides projected onto a white card.

Q: Can I use a Nikon Coolpix?

A: I can’t comment on specific cameras or projectors. I suspect your 3x zoom is not enough to crop into the slide — it depends on the distance from the slide to the side of the projector with its lens removed. In my first attempt with the Sawyer’s projector I considered taking a hacksaw to the projector to get the camera closer to the slide but took the easier route with a second-hand Carousel and a camera with 4x lens.

Q: You didn’t mention the stand-alone slide digitizers that sell for around $100-200, usually by mail order?

A: I checked these. It is the same principal, a quasi camera using a lens and sensor pre-focussed on a slide holder. The reviews indicated mediocre quality and you lose the ability to crop-in and the main advantage of a stack-loader to rapidly change slides.

Q: How did you fix the faded slides?

A: Not very well using Picasa but I only had a couple of hundred, Gevacolor, some early Agfacolor, and some early Ektachrome that I suspect was imperfectly processed. I understand there is specific software for image restoration and may look into this or try using layers in Photoshop Elements. The really bad ones I converted into black and white then adjusted gamma and contrast with quite good results.

Q: You are stupid spending all that effort for 4 megapixel images with low optical density?

A: Low? So suggest another way to digitise 500 slides an hour — or even close!