am new to Arca Swiss heads. I bought a SIRUI monopod head and am using that qr plate which is 2.33 inches long
the plate is a hair shorter than the tripod collar foot of the tammy;
I also bought an Acratech GV 2 ball head with no plate.
So, should the plate be a bit longer than the foot??
btw, am liking the acratech. very smooth, have not used the gimball feature
Not happy w/the SIRUI. I bought it because I wanted something more robust than my Manfrotto swivel head, and wanted the fluid tilt back. However, the tension knob freezes..literally in cold temperatures and won't move.
Your plate should be longer than your foot. It will help balance your camera and lens on your head. On my 100-400 I use a 4.5 inch Jobu Design dual dovetail Acra Swiss plate, which also gives me room for the flash mount. It's about $50. I also have a 5.5 inch plate (made in china) which works just as well for a lot less money. See this: http://www.ebay.com …ain_0&hash=item2ec74b83fa
I also have the Sirui head on my monopod. I like it, but never experienced the problem you encountered in the cold weather. I don't think I have used it in anything below 30 degrees F. Thanks for the tip.
When the weather clears, I will take the Tamron out for its trial run .