ARCA-Swiss started manufacturing precision cameras back in the 1950's, and over the years their cameras have been used my many pro photographers, including Ansel Adams. While they still sell large format cameras (see B&H), today they are perhaps better known due the to "Arca-Swiss" or "Arca-Type" plate and clamp systems that have been adopted as industry standard, and are currently used by a very large number of pro and amateur photographers (see here for a quick summary).
In its simplest form, the Arca-Swiss system centers around a 1.5" wide metal rail, with a V-Shaped groove cut into both sides. The picture below (courtesy of ) shows a typical Arca-Type plate with an integrated 1.5" wide Arca-Type rail underneath:
Obviously a rail on its own is of little use, so just as important as the rail, is a compatible clamp that grips the angled surface of the groove – as shown in the below photo of a Wimberley C-10 clamp on a Manfrotto Ball Head:
The basic design allows for a very strong connection between the clamp and rail, yet typically only a quarter turn of the clamp knob is sufficient to release the rail and allow it to slide out, making for a very strong, yet highly functional quick release system.
More recently, some companies have started making products that clamp to the top of the rail as well as the bottom, so many newer rails either have two grooves on each side (top and bottom), or a larger V-shaped groove that allows clamping top and bottom, as shown in the diagram below of an Arca-Type Plate (also courtesy of )
The above plate is 3/8" thick, and the image below shows the cross-section of a thicker 1/2" plate with a double dovetail, allowing clamping from both the top and bottom:
Another important feature that's built into many Arca-Type products are Safety Stops. Safety Stops typically consist of two tiny screws installed at either end of a rail (or plate or other Arca-Type device), as can be seen at either end of a Henjar PHOTO Camera Plate below. If you forget to tighten the clamp, or the clamp comes loose for some reason, the safety stops are there to stop the lens sliding out of the end of the quick release clamp. With both stops installed as shown below, you have to back out the clamp far enough to drop the plate or rail into it from the top (about a whole turn, instead of the quarter turn typically needed to release and slide out a plate). With just one safety stop installed, you can slide the plate into the clamp from one direction only. Using them is optional, although most people seem to prefer them, especially when dealing with big lenses that can cost more to replace than a small car.
Over the past couple of decades numerous companies like Wimberley, Kirk, RRS, Markins, Hejnar Photo and numerous others have adopted the Arca-Type standard, and developed a wide range of compatible products. Below is a brief summary of Arca-Type products available today:
Virtually every DSLR has a standard ¼" by 20 tripod socket in the bottom, to allow it to be attached to a tripod. A simple Arca-Type camera plate attaches to the bottom of the camera by screwing into this socket. Many manufacturers make universal plates, as well as plates designed to custom fit certain camera models. The universal plates are useful, in that they can be attached to any camera, so you don't have to keep buying new ones when you change cameras. Custom plates are typically designed to "grip" the camera better, helping prevent the camera being accidentally twisted off the plate when it's locked onto a tripod.
L-Brackets are basically camera plates that extend up one side of the camera, and provide a second rail. This allows the camera to be switched quickly and easily from portrait to landscape orientation, without having to adjust your tripod or head.
Larger telephoto lenses and some macro lenses come with built in lens collars/feet. A Lens Plate is similar to a camera plate, in that it screws into the ¼" x 20 tripod sockets in the lens foot, providing an Arca-Type rail. Many of the smaller lenses have just a single tripod socket in the lens foot, in which case a ridge is needed at the end of the plate to prevent it twisting off (see picture below courtesy of Hejnar PHOTO).
Larger lens feet typically have two or more tripod sockets, so work with a flat lens plate or rail with multiple screws (as in the picture below of a Custom Brackets GLM-1 Lens Plate).
Instead of screwing a plate into the lens foot, manufacturers like Wimberley, Kirk and RRS make replacement lens feet for specific lenses. These typically provide a stronger and more elegant solution, and in the case of Wimberley often reduce the height of the foot, making it easier to pack.
Obviously the Arca-Type rails are useless without clamps; so all the major Arca-Type manufacturers make clamps. There are universal clamps in different lengths, that simply screw onto a ¼" x 20 stud (tripod, monopod, omnipod etc), and some make clamps to mate with specific non-Arca ball heads (we use the Wimberley C-10MG with our Manfrotto 468MG for example). There are two basic types of clamps – ones with Knobs that rotate to open/close, and ones with Levers. Because of tiny differences between the widths and profiles of rails from different manufacturers, we tend to avoid the lever-style clamps because they offer a much more limited range of clamping action.
For more information on Arca-Type Quick Release Clamps:
Multi Purpose Rails are used any time you need to offset your camera from the center of the tripod or support, or want to attach more than one item to a rail. For example, shooting macro being able to move the camera a half inch forward without disturbing the tripod, or offsetting the camera/lens from the center of rotation of your tripod for stitched panoramic shots (we have a separate article on eliminating parallax for panoramas in the works).
For more information on Arca-Type Multi-Purpose Rails:
Similar to a Multi Purpose Rail, but generally has a built in clamp and a geared mechanism, which allows fine control sliding the clamp down the rail. Most useful for Macro Photography where small precise adjustments can be critical.
A number of manufacturers like Kirk, RRS and Markins make high-end ball heads with integrated Quick Release Clamps. Typically these are designed for heavier loads than the ball heads from companies like Manfrotto and Gitzo.
If you are using a heavy lens with a lens foot, a Gimbal Head allows you to balance the lens and leave it "loose" on the tripod. This allows you to easily and smoothly pan and tilt the tripod to track moving subjects.
As you can see, once you start buying into the Arca-Type clamp and rail systems, entirely new ways to blow your hard-earned cash open up, expanding numerous possibilities for both your future photography, and your credit card.
In general, if a product says Arca-Swiss or Arca-Type, then everything should be compatible. The one notable exception is the lever-style Quick Release Clamps (on their web site, RRS recommends you only use them with their own plates or Wimberley's plates), and in very rare cases a certain head or bracket may not clear something, so it pays to ask before you buy – we've spoken and/or emailed most of these companies at various times: most of these manufacturers are very small companies, and in every case we've found them extremely knowledgeable, helpful and responsive.