As lockdown continues in the UK (amongst other places) and it’s impossible to get out and about with a camera, it struck me that now would be a good time to digitize the mountain of old slides and negatives that are sitting in boxes in the attic and cupboards. In the past I’ve used a 35mm film scanner to kind of get started on the process, but the results were pretty disappointing as the resoultion wasn’t brilliant and the scanner always seemed to work as some sort of dust magnet.
My digitizing problem is made more complicated by the fact that my ‘archive’ doesn’t only contain 35mm film strips; I also have mounted 35mm slides, 645 film and slides and even some 6x6cm film. Getting hold of a scanner that can do all of them is likely to be an expensive business.
As an alternative, how about using a DSLR with a macro lens? The optical and sensor quality of that combination should be better than your average ‘consumer’ film scanner, and the good news is that I’ve already got camera and macro lens. In addition to these, the setup is going to need a suitably diffused (and even) backlight, some manner of slide/film holder and potentially an enclosure to hold everything in place and cut down reflections from the film surface.
I wasn’t going to be able to get out and browse the local DIY and craft stores for inspiration and parts, as they’re all closed. As a result the target with this build was that wherever possible I’d use materials that I already had lying around the house and garage. I did have to buy in the hockey stick tape, as that’s not something that I’ve had much call for previously, but other than that everything was already in-house for one reason or another. The result is a piece of gear that’s very ‘Heath Robinson’ and contains a lot more MDF and cardboard than I’d prefer. But these are strange times we’re living through, so I’m not going to worry too much about how (un)polished the finished product turned out to be.
Doing a quick test of distances from lens (filter threads) to slide/negative, with a crop sensor DSLR and Canon 60mm macro lens, gave me roughly 12cm with 35mm film and 25cm with 6x6cm film. That means there’s a fair amount of travel required when changing from 35mm to medium format film. My immediate thought on how to achieve this was to use a set of bellows. While you can buy various sizes of bellows pre-made, with a few cheap materials it’s also possible to make your own. I’ve wanted to try this out ever since I first read about how it’s done, so obviously that’s the option I chose for this project.
As far as the general setup is concerned, there’s a box with slider for a film holder on the back and bellows on the front attached to the camera lens. The whole lot is mounted on a camera slider to keep it all aligned and make it easy to adjust the film to lens distance.
- Camera slider (60cm long)
- Black card, 300 gsm weight
- Black Hockey stick tape
- 100mm filter holder
- 12mm MDF (thinner would be better, but that’s what I had)
- Picture frame back (2mm MDF)
- Wood glue, quick set epoxy and contact adhesive
- Black paint
- 1mm styrene sheet
These look complicated but making them is surprisingly easy, although it is fairly time consuming. For my bellows I used two sheets of black A4 card (300gsm weight), giving a set of completed bellows that are about 12cm square and anything from about 3.5cm to about 18cm long depending on how compressed/extended they are.
The first step is to mark equally spaced parallel lines across the card. I used 12mm spacing, so from the top at each side I marked at 12mm, 24mm, 36mm … all the way to the bottom. With A4 card the last mark is less than 12mm from the bottom, but that’s not a problem. Next, with a metal straight edge and a sharp knife score across the card following the lines marked earlier. When that’s done, again using straight edge and knife, cut down the centre of each card, giving four pieces of card 10.5 cm across and 29.7cm long.
Making the tube
Next take a piece of hockey stick tape slightly longer than the card and lay it on a flat surface, sticky side up. Place one of the pieces of card to one side of it so that it covers about a third of the tape’s width and press it down to stick it on. Then take another of the pieces of card and lay it down on the other side of the tape, again covering about a third and making sure the scoring lines up with the first piece. You should now have two lengths of card with about 8mm of sticky tape showing between them.
Take another length of tape, sticky side down, and press it down on the cards/tape directly above the first piece of tape. Trim off the ends of the tape in line with the top and bottom of the card. Now you should have two lengths of card with a flexible cloth hinge between them. Repeat the process until all four pieces of card are joined. To close the tube lie the sections out and lay a length of tape sticky side up over the middle seam, then fold the two side sections over so the edges stick to it. Finally add a length of tape to the outside of the last join and trim the ends.
The result should be a long square tube with lines scored across it on the inside:
Folding the bellows
Folding the bellows is quite a slow process and can cause a few crises of confidence the first time you do it, but isn’t difficult. With the tube standing on end in front of you, fold the top section of the side facing you outwards along the scored line. Turn the tube ninety degress and fold the top section that’s now facing you inwards, then turn the tube another ninety degrees and fold the top section outwards, and finally turn the tube another ninety degrees and fold the top section inwards. That’s the top row done! Turning another ninety degrees gets back to having the side you started with facing you. Moving down a row, fold the next section inwards along the scored line, then rotate and fold the next section outwards and so on. Work your way down the tube a row at at time making sure to follow the alternate out-in folding pattern. Eventually you’ll get to the bottom and will discover you have created a set of bellows.
In order to fix the bellows to the rest of the contraption, a plate of 2mm MDF was attached to each end. At the camera end this was cut to the outside size of the bellows, and had a 9cm diameter hole cut in the centre. This was then bolted to a (cheap) 100mm filter holder (using the screws that normally hold the filter slots in place). This gives an easy way to attach to the camera lens. The other piece of MDF was cut to the height of the bellows and about 5mm wider ar each side, this time with a 10.5cm (width) by 7cm (height) hole in the middle. Both MDF plates were glued to the bellows using impact adhesive. The final bellows assembly looks like this:
The sides, top and bottom of mine are made from four pieces of 12mm MDF (2 @ 9cm by 15cm and 2 @ 9cm by 9cm) glued together to form a rectangular tube 15cm wide, 11.5cm high and 9cm deep). The plates for the front and back of the box are made from a couple of pieces of 2mm MDF that used to be the backing of a picture frame. These were both cut to 15cm by 11.5cm.
The piece for the front had a rectangular hole cut 15mm in from the edge all round (so the cutout is 12cm by 8.5cm) and was glued in place. It then had 10mm plastic strips glued vertically at the outsides, and 15mm wide strips of MDF glued to these, giving a slot that the plate at the end of the bellows unit can slide into.
The back plate for the box had a 9cm by 6cm hole cut in the centre, then two strips of 6mm by 18mm wood glued horizontally on the outside at top and bottom, Strips of about 1mm thick styrene sheet, 25mm wide were glued on top of these. The result is a horizontal slot for the film/slide holder. The completed back plate was then glued and screwed to the back of the box. At this point the inside of the box was painted black.
Film holders were made from three strips of card about the same thickness as a 35mm slide mount, cut to fit between the slots on the back of the box: for mounted 35mm slides the outer pair have holes the size of a 35mm film frame, the inner one the size of a 35mm slide mount. It would have been good to use black card, but the only card I had in-house that was thick enough was grey so I used that. For unmounted slides and negatives the inner piece of card was replaced by thinner strips sandwiched to make a guide the film could slide through.
Setting it up
I used a camera slider to mount the copying setup on as I had one that was bought for an as-yet-unbuilt timelapse controller project: if that wasn’t lying around already a piece of wood could have done the job equally well at risk of making the contraption look even more agricultural.
The camera was mounted on an Arca Swiss style plate on the slider platform, and when it was coupled up to the box and bellows it was fairly easy to measure the amount the box needed to be raised so it was aligned with the centre of the lens vertically. This was about 21mm, so a spacer was made from a 3mm alloy plate attached to the bottom of an 18mm offcut of laminated oak, both of which I had lying around. The alloy plate had a hole drilled and tapped in the centre for attaching ta bolt through one of the holes in the slider rail, and finally a piece of 20mm plastic angle was attached to one side of the alloy plate to keep the box straight.
All put together it looks like this:
It’s a bit (very) agricultural, but given that it was almost entirely built with scrap materials it’s not too bad, and the results so far have been good. In use I’ve found the best results have been obtained by bouncing flash off a plain white wall as the source of backlighting for the slides/film.