I wanted to explain the mounts I use as well as how and why I use them. Many people swear by the Arca-Swiss style camera mounts, but I prefer the Manfrotto RC2 mount with the 200PL-14 plate. On speaking with some of the guys at Penn Camera, they tend to agree. The Arca-Swiss mounts may be durable and precise, but for me they are too slow and require me to look at the mount rather than just slapping the lens or camera on the mount an go. This ability to slap and go has served me well over the years, especially with my 400mm f/2.8.
With the 400mm slung on my back with the camera already on it, I have climbed ladders and run across the ground with my monopod in my hand. I first extend the monopod, which has a flat mounted 323 RC2 System Quick Release Adapter with 200PL-14 Plate on top, I then sling the 400mm off my shoulder with my right hand on the mount. With my left hand on the grip of the monopod and my right on the lens mount below the lens with my right arm holding up the lens and camera on the top of the outside of my arm, I rock the 200PL-14 plate on the base of the lens mount into place onto the 323 RC2 mount. It is the fastest means that I have come up with to quickly and securely attach the 400mm to a monopod. I use the flat 323 RC2 and not a ball head because invariably I found that the ball head would be in a precarious position when it came time to slap it down. Since I only have two hands, I prefer consistency and precision to a little extra flexibility.
Above, I have pictured the 200PL-14 Rectangular Quick Release Plate with 1/4"-20 Screw mounting bracket and the 322RC2 Grip Action Ballhead . I will use these two to show how I setup my mounting and show how quickly and easily the plates snap into place.
Notice on the 200PL-14 the labels LENS and the arrows. Well these indicate which direction the lens should be pointed relative to the plate. I actually use the plates backwards, with the camera in the direction of the arrow and the lens extending in the opposite direction of the arrow. The front element of the lens (where the lens shade is) would then be in the opposite direction of the arrow. I do this so that I can get the back lip on the base of the plate (the smaller lip edge) to slide into place as I rock the plate and snap it down to the mount.
In the sequence of photos below I show how this is done with a 70-200 f/2.8 lens, minus the camera. Notice how I fit the base edge into the back of the plate and just rock the lens forward. As the lens rocks forward it presses down on the brass pin on the mount, causing the locking latch to snap into place. With my left hand I can then check the latch, or I can just roll my right index finger around to check it as well. That is all there is too it.
To remove the lens, I just use the thumb on my left hand to press forward on the locking latch an the lens comes right off into my left hand. (Note: In the pictures below I used my left had to hold the lens because I was taking the picture with my right.) Once the lens is removed, I can easily fold out the ring on the bottom and connect it to my RS-4 Camera Strap by Black Rapid. The strap has a clasp on the end that the ring can quickly attach to. (I don't do this with the 400mm. I keep the strap that came with it from Nikon securely attached to it at all times. No one wants to drop that thing with a camera attached. I liken it to dropping a new car off a cliff.)
These mounts have served me well over the years and I hope that Manfrotto/Bogen will continue to make them long into the future.