Dampening Tripods

[Nathan Potter]

Tripod vibrations can be very complex. Essentially a tripod is a crappy way to achieve vibration free mounting of optical devices. But that's what we have to work with - although I've found heavy picnic benches are very good. But often the largest tripod head displacements are the result of resonances within some parts of the tripod or support system.

Now a basic principle of head displacement says that the higher the resonant frequency the less the displacement. Also the heavier the mass of the support system the less the displacement. So one can use these two notions to reduce vibration. Of course it really depends on what part of the support system is producing vibration - is it really the tripod or the device attached to it. Other posts here have suggested a plethora of innovative solutions which, in effect, reduce the resonant frequency of the tripod. Usually the problem is associated with the legs of the tripod. So:

1. Try to use as short of a leg extension as possible (higher vibration frequency).
2. Increase the weight of the tripod (use a bag of rocks suspended from the center
post).
3. Use bungee cord wrap around the tripod legs. (reduces the vibration period of the
legs so reduces displacement).
4. Shield the setup from vibration source of energy - the wind or ground shake.
5. Use auxillary support in addition to the tripod such as monopods.
6. For certain applications the use of bean bags or the equivalent function very well
and allow for limited adjustment of the optical device.

Nate Potter, Austin TX.

[rdenney]

To dampen your tripod, use the following procedure:

As a new member, I didn't want to go there, despite that my engineering brain was about to explode. Thank you.

Rick "who uses limp mass to damp vibrations and a garden hose to dampen soil, which makes a good limp mass" Denney

[Alan Davenport]

I once turned around to get into my bag and bumped the tripod with my caboose, knocking it and the camera over into a stream. That's about as dampened a tripod as I've ever seen...

Fortunately, I was reaching to the bag for a lens, so at least that wasn't on the camera yet. Still, it took hours to dry things off.

[Peter De Smidt]

Thanks for all of the suggestions. Currently, I'll have to stick to the tripods that I have. I've wanted to adapt some surveyor tripod style feet for my Gitzo for awhile, and so maybe I'll give that a try. I definitely need to be able to remove them. I'll also experiment with some materials to fill the center column/lower leg sections with. I like the huge steel pipe mounted in cement idea for telescope mounting, but that'll have to wait until I live in a better location.

Frank, I have some of the professional style sand bags on the way. They do work well, assuming one is able to carry them to the location. "Hey Janice. Could you carry these for me? It's only a couple of miles..."

[Jeff Conrad]

I think Nate summarizes it pretty well. A camera/tripod combination is a resonant system that's very dependant on the camera; in many cases, an 8x10 will be fine when a smaller camera is not. The older aluminum Gitzos are very poorly damped (as Ansel Adams noted years ago); my 412 has a tendency to "sing" in the wind with almost any size camera mounted. It has spike feet; pushing them firmly into the ground helps quite a bit, as does avoiding extending any leg section completely (i.e., leave a couple inches of overlap to decrease flexure at the joints).

It's probably someone akin to the turntable support debates of 25 years ago. On one side were the proponents of the rigid-base Japanese turntables like Denon and Pioneer; they worked best with massive, absolutely rigid platforms, such as heavy furniture or even a concrete pillar that came through a hole the enthusiast had cut in the floor. On the other side were spring-suspended turntables like Thorens and Linn, which worked best with very light stands. A camera/tripod combination is probably somewhere in between. The point? It's a system rather than two individual components.

Sand bags certainly help, but of course you need to carry them. Years ago, I used a tripod apron that I would fill with rocks, and this worked to about the same effect. The apron was attached to the middle leg sections, so it also served to limit the displacement (and the vibration amplitude) of the legs. But rocks aren't always available, and in some cases picking them up makes a mess of things, so hanging a camera bag from the tripod apex may be a better solution. I usually use an adjustable loop of tubular nylon webbing to have the bag just touch the ground so that it doesn't pendulum.

Carbon fiber is probably the easiest solution, but it doesn't help if you're not in the market for a new tripod.

It's possible that some of the various damping techniques discussed will help, but as Nate implied, it's crapshoot. I was amazed at how effect cardboard tubes in driveshafts were in reducing truck noise (the driveshaft usually worked as an amplifying device for transmission noise). Whether urethane would do the same for a tripod is uncertain; I'm guessing it wouldn't do all that much.

Various decoupling schemes might reduce vibration from some sources (such as the ground) but could exacerbate the effect of other sources such as wind or even jarring from a cable release. I'm skeptical of something like a rubber mat in most cases; although it might reduce ground-induced vibration, it might also make for a pretty bouncy setup. For example, the hard rubber Gitzo feet are notorious for sliding on marble floors, but bounce they don't. The softer feet on many other tripods are less given to sliding, but some are so soft that even getting near the tripod seems to cause camera motion. It's all a matter of tuning, and it may be possible to get a setup that's optimal for most conditions, but it might require a lot of work. I'd try some of the simpler, reversible things before getting fancy.

The best way to test would be to use an accelerometer and a scope, but most people (myself included) don't have these handy. As a cheap, easy alternative, you can observe quite a bit by looking at the groundglass while tapping a leg, and confirm the more promising possibilities with images. A simple test like this very quickly shows the effects of weights, leg overlap, and CF legs.

[Terence McDonagh]

As a new member, I didn't want to go there, despite that my engineering brain was about to explode. Thank you.

Rick "who uses limp mass to damp vibrations and a garden hose to dampen soil, which makes a good limp mass" Denney

Your fellow engineers feel your pain . . .

[emo supremo]

1. Can anyone relate their experience with a spreader? Yesterday I saw a contraption that folded up (portable). the feet of a tripod were jam nutted. I couldn't make out whether it's purpose was to prevent pointed metal feet from inscribing parkay flooring or to add stability to the tripod. anyone know?

PORTABLE SPREADER FOR RIES ZONE VI MITCHELL TRIPOD NR Item number: 280338947958

there's a similar one for Bogen 3155 Lightweight Spreader for Tripod Manfrotto Item number: 300274966099

2. Has anyone tried placing a strut from the camera leg to the tip(s) of the baseboard. I viscerally dislike the base of the camera affixed by a dainty 3/8 inch screw and the leverage the front of the camera has on this pivot point gives it dictator's power. All these tripods are like shooting a pistol when you ought to be thinking rifle. I think (think, dont know) that brodening that pivot point by to vertical struts coming up from two of the legs ought to make it stable. Put a little yin and yang in them opposing forces. Any telescope people care to comment?

This smacks of the figure on page 47 of how to use a monopod (Ernst WILDI third edition) to wit, "The steadiest position for a monpod is when it forms a third leg....and the camera is pushed firmly against the face.....two forces oppose each other, which is not the case when the monopod is vertical."


3. I like the isolation strategy proferred in the last threads. We have balances that measure fractions of milligrams and they are on marble (massive weight) but resting on on massive legs but rather rubber! Michaelson and Morley floated their equipment in a vat of mercury to eliminate vibrations. Is there a lesson to be learned in these anecdotes? Someday I'm going to cut a tripod in half and put shock absorbers in between the three cut legs. But before I do, I'm going to try using bamboo.

[Peter De Smidt]

I've ordered some Spectrum vibration damping coating. See: http://www.secondskinaudio.com/sound...p?category=121

I'm going to coat my DIY panorama head with it. If that works well, I'll investigate coating various surfaces of my older tripod and head with it.

It's pretty pricey, but I plan on also using it in the wheel wells of my wife's Honda Civic, which has quite a bit of road noise.