Tue 29-Jan-13 10:54 PM | edited Wed 30-Jan-13 03:55 AM by bobpilot
> >My copy of the 2008 Gitzo catalog shows the Series 3 tripods >suitable for lenses up to 300 mm focal length. Series 4 >tripods are rated for 400 mm, and Series 5 for 500 mm. The >chart does not extend to 600 mm focal length. These limits >are a function of torsional rigidity.
Does this mean that my 3500 is not adequate?
> >The Nikon 300 mm lens weighs 6.4 pounds, and the 600 mm F/4.0 >weighs 11.2 pounds. Add the weight of the D3S camera (2.75 >pounds) and the RRS pano system to the 600 mm lens, and your >are probably at something over sixteen pounds or so, which is >well within the maximum load limits for the Gitzo Series 3 >tripods: 26.4 pounds for aluminum legs, and 39.6 pounds for >the carbon fiber legs.
OK, so my tripod is adequate. I'm confused.
> >As mentioned above, torsional rigidity may be an issue here, >particularly if the tripod is extended to its full height. Is >the tripod a three or four section leg model? The 600 mm lens >has a field of view (FX format) of 4.17 degrees. If you can >examine the original image above to see if the apparent >movement is lateral, we may have narrowed the issue down to >possible torsional movement.
My tripod has three section legs. Is the halo caused by vibration? > >Before you purchase another heavier tripod, can you repeat the >test with the configuration on a concrete slab?
the last shots, not yet posted, was on concrete, subject was a ruler.
>Is your location subject to heavy truck, bus, or other vehicle >traffic? Our house backs up to a fairly busy arterial road >and I can feel the vibration in the floor when a heavy truck >goes thundering by.
> >If this exercise is inconclusive, we may have to look at focus >issues. I assume that this issue has occurred with the 600 mm >lens only, correct?
Well, that is another test I need run; try another lens. I had focus issues with my 600 in Zion last month, but I attributed that to my technique. Last fall, I shot a Civil war reenactment, guys in battle, and got some sharp and some not sharp images. (600mm lens)
How should I post the images? my web page, which I can share here via a private link. I can crop tight, but I can't tell if the crop is a 1:1. I will also post some examples here.