I've been interested in trying out the lens support package from RRS for a while now so when I found one over on FM for a great price I decided to grab it and do some testing. Link to RRS site if you aren't familiar with the product: http://www.reallyrightstuff.com ...ng-Lens-Support-Packages/ Hopefully this will be informative for anyone else that may be looking at the support kit themselves.
Results so far have been interesting, although I wouldn't say my sample size is large enough yet to be definitive. In single shot silent mode the effect of the support doesn't start to become apparent until very slow shutter speeds, slow enough to not be worthwhile if you are shooting anything that moves. A more obvious benefit comes when shooting in burst mode, and is apparent at shutter speeds that are relevant for wildlife photography and similar. Bottom line, the support does work; but whether or not you would realize it's benefits depends largely on what you are shooting and under what circumstances.
For this test I was shooting a deck of playing cards near minimum focus distance. All shots with a 1DsIII with EF 500mm f/4 IS, at both 500mm and 1000mm (with 2xIII). Support was a Gitzo CF tripod and Wimberley WH-200 and of course the RRS Long Lens Support (LSS from here on) either engaged or not.
My test subject, this is the full image at 500mm, 1/25, resized, and is shot 6 from a 6 shot series with the LLS engaged.
500mm, 1/25, resized, shot 6 in 6 shot series, no LLS.
So, not much difference can be seen in these when resizing for the web (although if you look at the text on the pull out flap you can notice a small difference). Let's look at some 100% crops.
100% crop, 500mm, 1/25, shot 1 of 6 shot series, with LLS
100% crop, 500mm, 1/25, shot 1 of 6 shot series, no LLS
Right out of the gate the LLS has had a noticeable effect on the first shot in the sequence.
100% crop, 500mm, 1/25, shot 6 of 6 shot series, with LLS
100% crop, 500mm, 1/25, shot 6 of 6 shot series, no LLS
By shot 6 the difference is significant as seen in the above two photos.
Here's the full series with support (shot 1 upper left, shot 6 lower right).
And without (shot 1 upper left, shot 6 lower right).
I repeated each of these series several times and got similar results. It's clear to me that the LLS helps to minimize vibration, and is particularly good at stopping vibration from ramping up during rapid shooting. I want to repeat the test at 500mm and 1/125 and 1/60, but ran out of time today. I did shoot a series at 1000mm and 1/125 which I will share a sample of below.