From the mailbag:
I was wondering if you would be willing to test the proposition that one should always extend the thickest legs first when setting up a tripod. I suspect this is not true for RRS tripods and DSLRs. I’m asking partly because confirming or dispelling old wives tales is fun, and partly because I get photographers giving me a hard time when they see me doing the reverse. Most of the time I am shooting using a RRS tripod (TVC-33 and TVC-44) and loose gimbal with super telephotos at high shutter speeds and image stabilization, so the platform rigidity is not so critical. I like to extend the bottom legs first because when I need to tweak the height of any leg I don’t have to reach way down but can adjust the most convenient section – the top one. Anyway, for RRS tripods, does it make any difference under the most rigorous DSLR use case? Not as far as I can tell, but I do not have your sophisticated equipment/knowledge at my disposal.
There are two kinds of vibration that tripods usually are used to mitigate, and a third that describes your situation.
The first is vibration introduced by the camera. The two most common ways this can be done is through mirror slap or the first curtain starting and stopping. With mirrorless cameras like the M240 and the a7R, winding the shutter is also a cause of vibration. The best way to deal with this kind of vibration is to avoid it in the first place. Use cameras with electronic first-curtain shutter (EFCS) or leaf shutters.
I have procedures for testing the camera-induced vibration, and seeing how various tripods, heads, damping strategies, and cameras deal with it. There are limitations. I can’t get more than about 25 feet from the target, which limits the lengths of the lenses to be tested. I don’t have a laboratory where I can leave equipment set up, so I need to establish controls for each session. I can’t deal with ground coupling options since the only surface I have is vinyl tile over concrete.
Because there are now quite a few EFCS cameras available, and more undoubtedly on the way, I have little interest in finding ways to mitigate camera-induced vibration. One project I could undertake is testing my assumption that EFCS allows continuous-lighting resolution approaching strobe resolution with ordinary tripods.
The other kind of usual tripod use is to prevent the camera from being influenced by environmental effects, usually wind. Note that the stiffer a tripod is, the worse it will be in mitigating the effects of ground-borne vibrations. In this case, mass and stiffness are your friends, but, like the situation above, the best way to deal with wind vibration is to shield the camera from the wind, not let the wind have its way with the camera and try to deal with the results.
I have no way to test tripods that are intended to mitigate the effect of air currents. First, I’d need a way to generate repeatable currents. I suppose I could use a fan for this. Second, I’d need to do a lot of averaging, since wind effects are chaotic. I just haven’t done that work.
Your situation is even harder to test. It’s probably best thought of as assisted handheld shooting, and would need the same kind of statistical approach. In addition, I think the difference between performance with the two different leg-extending strategies will be minimal, and will probably by swamped by statistical variation until the sample size grows so large that making the captures could be thought of as cruel and unusual punishment.
If, by the most rigorous DSLR case, you mean D810, Zeiss 135mm f/2 APO, no wind, hard floor, EFCS on, I can’t imagine that the leg extension order will make any difference with good carbon-fiber tripods like the ones you own. I will try that configuration (extending the small legs first, which is what I do, too) with a continuous light source against a strobe. If they’re essentially the same, then there’s no point in extending the big legs first. If they’re not, then that’s something to look at.
Would that be a help to you?