If you've ever wanted to photograph something the size of an aphid or a grain of rice, what you've wanted to do was macrophotography. A typical camera lens will not generate useful images of such small items, but there are several ways it can be done.

You can get special macro lenses which will be designed to photograph the very small. These will generally be expensive and very good at the job they are designed for.

You can add a corrective lens onto the front of an existing lens, to make it more near-sighted. These are often referred to as close-up or macro filters. These are rather limited in their usefulness, but are an inexpensive start into macro-photography.

Reverse mounting a lens on your camera is possible with adapters. This will take a lens which makes a small image from a large object and make a lens which makes a large image from a small object. You can also reverse mount a small lens on the front of a long lens. I don't have experience with these methods beyond the basic idea.

The final method is to put some space between a normal lens and the camera. The greater the distance added between the lens and the camera, the more near-sighted the lens will become. You can either use fixed-length extension tubes or a variable-length bellows. The further the lens is moved from the camera, the more spread out the light will be.

I do most of my shooting with a Canon EOS series digital SLR. Canon macro lenses are generally too expensive for my budget. Macro filters are not so useful, but using one did get me more interested in photography of the very small kind. Canon doesn't make reverse mounting adapters and I didn't have extra lenses around to play with. Canon makes a couple of extension tubes, but they only work with specific high-end lenses I did not own. Canon made a few bellows for their older lines of cameras, but have not yet decided to produce one for the EOS line.

Canon EF series lenses require electrical connections to the camera body to be completely functional. The lenses can be used in a limited way without this connection, but the loss of autofocus and other features led me to decide anthing I got would need these connections. There are several producers of extension tubes for the EOS line, but the flexibility of a bellows compared to an extension tube set appealed to me. Novoflex is the only company I've found to be making a macro bellows with electrical connections. Unfortunately, this accessory runs about 650 $US before shipping.

I was left with either too expensive or too limited. I really liked the idea of Novoflex's auto bellows, but I really didn't like the expense.

I decided I would just make my own. The idea didn't involve hand grinding any optics or making custom electronics to interface the camera and lens, it was just a bellows with some wires. Why not?

It worked, and if you've gotten tired of my writing... well, you just got to the interesting part.

Tools:
	A dremel tool and various bits.
	A good small screwdriver set.
	Hot glue gun and hot glue.
	Soldering iron and solder.
	Some hard epoxy.
	flat black paint. (optional)
	ear/eye/respiratory protection.

Parts:
	Some multi-stranded wire:				an old parallel printer cable, <$10 new.
	The cheapest 35mm camera bellows I could find:		Minolta series 3 bellows, $36.
	A broken EF lens:					Canon EF 35-105mm, ~$30.
	A broken EOS body:					Canon EOS Elan, ~$30.

I later got a broken Quantarray EF lens from a local used/new camera dealer simply by asking. It might have helped that I purchased ~$550 of new equipment just a minute before, but it shows they can definitely be had for less than I paid. I expect trashed EOS bodies can also be had for much less than I paid. This was my first build, so I just consider it a lesson learned.

The first stage in any build is to tear apart and toss anything you're not going to use. I actually saved much of the scrap for other projects, but there's no need to.

We only want the mount and electrical contacts from the lens. There are three or four screws holding the mount onto the lens body. The dremel with a cutting bit helps get rid of all that extra plastic and glass in the center of the mount. The contacts were soldered into a little board just on the inside of the lens. I could have desoldered it, but since I had the dremel handy, I just ground the board into powder.

From the camera body, again, we only want the mount and electrical contacts. The procedure for separating these specific componants from the rest of the camera is long, involved, and mostly just breaks down to pulling and cutting until everything else is gone. What, you want to use those parts? Then you can be more careful and directed about your disasembly. It didn't occur to me to document each stage of the process I took. Perhaps you could find a repair how-to if you aren't already good at taking things apart.

There are a few things to keep in mind while doing this. The mount consists of at least five parts which need preserved: the mount ring, the tensioners, the spacers, the mirror-box, and the contact assembly. The mount ring is just the metal ring at the front of the mount. The tensioners are the rounded flat springs which help to hold the lens in place when attached to the camera. The spacers may or may not be present and are thin metal flat rings which are placed between the mount ring and the mirror box. The mirror box is the large plastic box where the mirror was. The contact assembly is, well, the contact assembly. It will be easier on you later if the eight wires coming off the contact assembly remain relatively intact. I didn't leave these wires intact, but it's not a fatal error. Almost all of the mirror box is going to be discarded, so you can safely grind away everything past the back of the contact assembly. If you can keep the lens locking pin mechanism, you will be able to use it later without the effort of building a new one. I advise you keep it in good shape.

As almost any bellows will work and it is not likely you found the same one I did, I won't be able to give directions any more specific than I already have been giving. The objective is to remove the existing mounts from the structural frame of the bellows. With the Minolta Bellows III, the lens and camera mounts are screwed into cast aluminum frames. Some of the screws holding the mounts in place were only accessible from the inside after detaching the fabric bellows. The fabric bellows is attached by end plates with four screws each. With Your Bellows(tm), the lens and camera mounts may be unified with the two frame pieces at the ends of the bellows. If so, you'll have more machining work to do than I did. If your bellows' frames are made of tougher material than aluminum, you'll have far more machining work to do than I did.

The camera-side mount is relatively easy to finish. Center the male-mount from the lens on the camera end of the bellows (the end which doesn't move relative to the tripod mount). You'll see the backside of the lens contact assembly doesn't quite fit, so we need to carve out a chunk of the structure so it will fit. You can solder the multi-stranded wire to the backside of the contact assembly before or after you attach the mount to the bellows frame. I attached the mount to the rear frame piece by using a thin layer of epoxy. I advise being very careful with how the mount is rotated. I epoxied my mount at slightly the wrong angle and now I'm stuck with it. You can drill some holes and screw it in place if you're feeling adventurous.

I put down a layer of hot glue for reinforcement after I soldered the wires in place. You really don't want these connections failing when you're in the field. It is helpful to use a multi-colored wire strand. If you accidentally miswire the back to the front of the bellows, you could fry your lens or your camera or both. I trimmed off more of the grey outer casing to the cable, flattened the wires into one layer, and screwed down the end plate of the fabric bellows. The wires were thin enough the end plate could be reattached without much effort or deformation of the end plate.

The lens-side mount was much more complex. There were a several constraints at this stage. I wanted to minimize added length to the device. I wanted to keep the locking pin mechanism functional. I wanted the contact assembly to remain functional. I wanted the mount to still do its job when I was done with it. What followed was an iterative process of removing unnecessary plastic and/or aluminum and seeing if the pieces fit together the way I wanted. After a while of this I had removed enough of the front bellows frame that the pared down contact assembly and locking pin mechanism both fit. A little while later the various pieces fit better and the mount ring was flush to the front surface of the frame. The front surface of the bellows frame had a depression around the opening which replaced the need for the spacer rings of the mount. Some epoxy to hold things in place and fill in the gaps from the iterative removal process and the mount is done.

If you left the original wires attached, all you now have to do is match up your relay cable to these wires and you are done with soldering. I didn't leave the original wires attached and the mess you see in the photo to the right is what I got for it. It helps if you've measured to make sure you have enough relay cable for when the bellows is fully extended. I didn't measure this and got lucky as I had just enough cable. If you miswire this relay cable, you may fry a lens, a camera, or both. Don't get this wrong.

The bellows end plate at this end required some modification to let the wiring and contact assembly fit. Again, this was the result of an iterative process instead of a predesigned plan. There is a thin edge of the end plate at the bottom. This edge helps to hold the wiring in place when the end plate is screwed back into place.

If everything went according to plan, you'll now have something which looks about like the photo on the right. If things worked out better for you than for me, your relay cable might even look professionally done. If your relay cable turned out to be eight individual wires, I guess you could wrap them in electrical tape to avoid the scorn of your neighbors and coworkers. Test all of the connections before you attach your camera and lens. Otherwise when you attach your lens and camera to your new bellows, you might find you didn't solder one of those connections quite as well as you thought or that you actually did miswire something. Hopefully no damage is done and you can simply fix the problem.

If you did destroy some of your valuable property, it's your fault for performing a build you were unqualified for.

If you want to reduce any internal reflections, you can open the project back up and coat anything which isn't black with that flat black paint I listed in the tools/parts section. I haven't done this yet for my bellows. It is on my list of things to do, but the results I've been getting lead me to believe it isn't a serious issue.

A design flaw in the bellows described above is the lack of strain relief in the relay cable. This flaw was made apparent while I was in Florida trying to photograph ants. The bellows worked for a couple of shots, then a wire broke and that was the end of close up photography for that week.

My present version uses a stretch of 8-conductor coiled cable I found at my local surplus shop. Instead of directly connecting the cable to the bellows I decided to use a standard plug. Due to the size constraints and the need for seven connections, I settled on SATA ports. I ordered some male ports from Mouser and used female plugs from an extra SATA cable I had laying around.

After some delicate soldering, I needed to securely attach the SATA parts to the cable and bellows frame. I had to apply the epoxy rather thickly to the cable to be sure it wouldn't simply bend out of the way when force was applied. The end result is a niceflexible cable which plugs into the bellows frame. If I'm using a non-electronic lens than I can just leave it in the bag.

Once everything works, and if you have the appropriate pets, you can go and take pictures like these.

It looks like I'm not the only person around who thought it was worthwhile to hack a bellows onto a modern Canon camera.

• http://www.acapixus.dk/photography/EOSbellows.htm