Novoflex Chest/Shoulder Pod - Reduces Handheld Camera/Lens Movements

It has no problem with my Nikon D5 and a 200 - 500mm lens.

Yes, the Novoflex Chestpod / Shoulder Pod can be used in a sitting position for taking videos of fireworks.

The usefulness of this device comes down to personal preference. In the movie business we called it doing whatever it takes to get the shot! From what I see of birders and my own shooting of wildlife, I would recommend you first try using the Tamron lens hand-held, particularly for BIF. If you find yourself tiring or you need to keep the lens to your eye for long periods (on a nest for example) then give this a try and it may be the answer for you.

You can get the bracket and base shown in the Chestpod photos. Novoflex Q=Mount Arca-Type Manual-Locking Quick Release Adapter - Requires Plate B&H # NOQM and the Novoflex QPL-Vertikal L-Shaped Quick Release Plate for Q=Base System B&H # NOQPLV.

It is a tool and it's success depends on how you use it. If you do not wish to use tripods or monopods, then try and see if it works for you. The main technique you would have to master is taking in a deep breath, letting out half of it, and then holding still while you shoot. Otherwise, your breathing will be an issue with such a lens. Other techniques is keep your shutter above 300th of a second and use higher ISO for hand-holding your camera.

completely adjustable.

Yes it does. It has the standard removable plate with a male screw. Once that is removed, the remaining base plate has a 1/4 inch hole.

I use my PISTOCK-C to support binoculars. Based on that, I very much doubt anyone could hold still enough over 30 seconds to get a non-blurry picture.