The Peak Design Pro Camera clip is a device that allows you to support your camera by attaching the camera to your belt or pack strap. I was sent one of them to review for Backpacking Light. Although it is well designed and very reliable, it has a target market which may not be for all BPL members.
The Capture Pro (from vendor web site).
The photo here shows the main part of the unit. The 'back two' parts are a secure clip which can be attached to the shoulder strap on a pack or to a large belt. The red square bit at the front screws onto your camera using the standard 1/4 in Whitworth screw, and then slides forward to attach to the main clip.
The two big black round knobs are what holds the clip to the shoulder strap. They screw down and clamp. The square red knob is a quick release for the mounting plate giving quick access to the camera; push in on the knob and remove your camera from the clip. The small round knob is similar to the square red knob except that the round knob is a screw lock - so your camera cannot accidentally detach itself.
The Capture Pro is mostly solid aluminum and weighs about 5.3 oz (149 g). It costs around US $80.
The Capture Pro in use (from vendor web site).
These two (vendor) photos show the Capture Pro in use. It is easy to see that it has versatile applications.
There is no doubt that this clip works just fine for large heavy DSLR cameras with big lenses, you can even detach the camera with one hand - just make sure you don't drop it! The clip is very secure and there is little danger of the clip accidently releasing your camera.
The instructions suggest you clip it to your left shoulder strap so you can easily reach it with your right hand, or to your waist belt to take the weight off your shoulders. However, my experiences are detailed below and tell a slightly different tale.
Sadly, I don't think the designers of the Capture Pro are on the same wavelength as me. I carry a Canon G15 camera, and I found the Capture Pro just did not work for me and my camera.
The clip weighs approximately 5.3 oz (149 g). Currently, I use a MYOG X-Pac camera pouch weighing just 1.6 oz (45 g).
While traveling through the forest, the clip leaves the camera exposed to all the passing brushes and debris as well as the bad weather; my camera pouch protects the camera from both the elements and trail hazards.
The use of the clip makes my camera stick out oddly and wobble around while in movement. Conversely, a camera pouch keeps the camera much closer to me where it is stable.
Putting the clip on the left shoulder strap as recommended was seriously bad advice. When I swung my pack up onto my shoulders (hey, it's UL, isn't it?), the heavy lumpy camera and clip swung flying around banging onto nearby things and into me. In fact, I would say you should never mount anything heavy on your left shoulder strap. (Left handed people should reverse all my comments.)
Putting the clip on my pack waist band was ... well, I didn't do it because the way I see it, it’s a fine way to drop your camera into the dirt with your pack on top of it.
You could put the clip on a heavy belt, but I never wear one.
The Capture Pro may work very well for some people with a large DSLR with a big telephoto lens, travelling in open country, and it may well be one of the better ways of carting such a beast around, short of concealing it inside your pack. Even so, you often need to arrange for some weather protection.
An even more pressing issue is where do you attach the clip. Some options are to put it on a pack shoulder strap, but that requires that you put your pack on by sitting down in front of it. But for anyone else, especially UL walkers, the Capture Pro clip is probably just not the right idea. The Capture pro might work better in a more urban environment carried on a day pack. For lighter cameras, ranging from large P&S ones to pro-compacts with retracting lenses, an alternative to the Capture Pro Clip would be a be to use a camera pouch and place it on the right shoulder strap.
One of the best alternatives I can suggest is that I make my own waterproof light-weight pouches to fit my cameras. This is an option for you to consider. It works well; I can usually get my Canon G15 out with one hand fairly fast, so as to catch those transient happenings; someone falling in the river, that sudden magical view, whatever. Since they are waterproof, I can still use the pouch in bad weather - where the best photos sometimes happen.