good head for 400mm f5.6 and TC

I already have a manfrotto 701RC2 video head, but realize I have a flex in the head, especialy when the TC are added and so a shaky image in the viewfinder. Any suggestion?

I presume you are clamping the lens foot to the head and not the camera body for better balance? Actually I did a test and found that with the camera body clampled to the head there was less vibration, however, with the 11" lens and 1+" TC cantelevered out front, adjusting the camera framing was impossible. I use a 1DmkII, so its a pretty heavy body.
I used to use a Acratech Ultimate ballhead but found the droop after tightening to be frustrating. I figured that a heavy lens/camera combo was actually flexing the head and support bearing. This can actually flex the tripod legs too, and is noticable with a really strong head (because its not the head flexing, I now use a RRS BH55) when the weight load is not very centered over the tripod.
Have you considered something like a Wimberley Sidekick? You will need a AS lens foot plate and AS compatible clamp too, but this can center the weight for easy rotations and thus minimizing tripod/head droop.
http://www.tripodhead.​com
Mike K

Hi Mike,
I use the foot colar. I have a look at sidekick but it's a bit too much for the lens and me. The ball head seem interesting and stable but lack the flexibility of the video head for paning. Maybe a manfrotto 501?

this is for a tripod i assume. well i never really use my 400 5.6 on the tripod, since its so light, but if i did i would use my 488 RC2 manfrotto ballhead. a wimberly sidekick would work well, but is quite overkill.

ps. unless you are shooting low shutter speeds are really need the tripod i would work without it.

With the wheater we have here it's difficult to have very fast shutter speed, so 75% of time I use the tripod. Ithink also the sidekick are a bit overkill. with the TC it give close to 850mm so it's difficult to be not shaky handheld.