I often shoot my 70-300 at or near its long setting, while attached to my D90 on a manfrotto tripod with a strong ball head. But it always seems that this lens would benefit from a mid-length support, like those on higher-end Nikkor telephotos of similar zoom lengths, especially if there's wind. I'm wondering whether anyone has seen any sort of after-market support/rail/attachment that would provide this?
I have a longish rail made by Really Right Stuff (RRS) and these are also supplied by Kirk. All of these require an ACRA style system, so their use would require you to at least buy an adapter for your Manfroto system unless it is ACRA ready. I purchased my rail (about 5-6" long) for a different purpose. For your purpose it would center your camera/lens somewhat better over the ballhead, but I don't really see a big need to do that. I have the 70-300 VR lens. It is a good lens and I give it good use. I have not seen any kind of aftermarket collar for the lens. Note too that Nikon has just introduced the 70-200mm f/4 lens which (I believe) is longer extended than the 70-300mm - the collar for this lens is optional and some Nikonians see no need for it.
I have the Manfrotto 293 support and used it with my old 1-ring 80-200mm f/2.8, but I can't really recommend it for the 70-300mm VR due to three issues:
1. The support weighs 700 grams. Since the 70-300mm VR weighs 745 grams, it nearly doubles the weight of the setup. 2. The support only works in landscape orientation. For portrait orientation, you have to rely on your tripod head or add a Junior Elbow Bracket for another $70 and 320 grams. 3. The front barrel of the 70-300mm extends as you zoom. It may extend with focus as well; I can check next time I'm in the same state as the lens. But either way, it means that in order to use the support, you have to leave things loose until just before you're ready to take the shot.
So while it may not be optimal, using the camera's tripod mount may be the "least bad" option.
One of the biggest mistakes a photographer can make is to look at the real world and cling to the vain hope that next time his film will somehow bear a closer resemblance to it. - Galen Rowell
Thanks to all for commenting. Looks like I may be chasing something that isn't really needed in the first place, although it does seem like a pretty long amount of lens hanging off the mount when at the 300mm extension. I'll take your collective advice and stick with the regular setup.
This will do what your asking for, the question is price. I am arca compatible already. I have a couple of bars etc. I have been considering the parts to make this available for my light weight kit. I think a couple of these parts plus what I have will do the job. If you are already Arca plate compatible, you get some good pieces with the kit. I have not pulled the trigger on this myself, and usually shoot my 80-200 from the tripod and not my 70-300 VR. I do suspect that there is better sharpness to be had at 300mm with that lens, which got me looking as well.
You may not be chasing something that is not needed....Thom Hogan feels that the long extension of the lens can induce vibration; you need to read his review. There are techniques that you might use to lower the induced vibration as well. Experiment with your setup to see how you can use it to best advantage - what works best for you...photography is like many other things in life, a long road filled with challenges. Have fun, and good luck!