Equipment Choices 2

Here is a photo of three extension tubes for the Canon EOS system. This set has tubes of about 30 mm, 15 mm, and 7 mm in length. They can be used in any combination and any order. The pen is stuck through one of them in order to show that they have no glass in them; they are simply light-tight spacers.
Extension Tubes
Extension Tubes
Extension tubes are glassless tubes which fit into your camera lens mount and which the lens then is mounted on. They effectively move the lens further from the camera body and thereby permit it to focus closer. They come in several sizes, and may be either automatic or non-automatic. The automatic ones permit the camera to maintain control of the lens aperture as if the lens were still in its usual location on the camera. These are much more useful than the tubes which do not maintain this electrical connection. The tubes can be used with any lens which will mount to the camera. Be aware that there are two varieties of lenses for the Canon EOS mount; one for so-called crop body cameras (the EF-S lenses) and one for the other cameras (the EF lenses). The newer tubes are designed to fit either body type.
These tubes may also be used with telextenders (see below). They are made by a variety of reputable manufacturers (Canon, Kenko, etc.) or by others. It is probably best to stick with the reputable manufacturers. They come in a variety of lengths; probably the best deal is from Kenko, which has a set of three for about $180. The set includes a 12mm, 20mm, and a 36mm tube (I think).
Bellows
Bellows are essentially flexible and variable versions of extension tubes. One end mounts to the camera and the other end has the lens attached to it. Then you can adjust the overall length of the bellows to yield exactly the extension you need. Such a setup is used exactly like extension tubes, with the difference being that the bellows is almost always clumsier to handle. In the field this can make a considerable difference in getting the shot you want. Not only that, but bellows setups tend to be somewhat more fragile than extension tubes. Still, sometimes you can find a good deal on a used bellows. At least one manufacturer makes a bellows system with tilt and shift capabilities, and this could be ideal for studio use.
These tubes may also be used with telextenders (see below). They are made by a variety of reputable manufacturers (Canon, Kenko, etc.) or by others. It is probably best to stick with the reputable manufacturers. They come in a variety of lengths; probably the best deal is from Kenko, which has a set of three for about $180. The set includes a 12mm, 20mm, and a 36mm tube (I think).
Bellows
Bellows are essentially flexible and variable versions of extension tubes. One end mounts to the camera and the other end has the lens attached to it. Then you can adjust the overall length of the bellows to yield exactly the extension you need. Such a setup is used exactly like extension tubes, with the difference being that the bellows is almost always clumsier to handle. In the field this can make a considerable difference in getting the shot you want. Not only that, but bellows setups tend to be somewhat more fragile than extension tubes. Still, sometimes you can find a good deal on a used bellows. At least one manufacturer makes a bellows system with tilt and shift capabilities, and this could be ideal for studio use.

Here's an expensive bellows from Novoflex in Germany. This one is very nice, solid and sturdy, and it has a dual carriage, so that you can move the entire assembly without changing the length to which you have set the bellows. Cheaper bellows are readily available from Amazon or eBay, but they may or may not serve you as well as this one. Novoflex also makes a bellows with tilt and shift capabilities, but it is extremely expensive. Nikon used to make one, and it might be available used. Canon used to make one for the FD mount, and those are sometimes available, but would need mount adapters.