“Vibration resonance” – does your tripod suffer from the shakes?

[aduncanson]

Mr. Adams' statement "Every object has a resonant frequency, and if the wind or other force sets up vibrations at that frequency, they may persist for 10 seconds or longer.” is not accurate and may give rise to misunderstanding. The problem is not as simple as avoiding stimulus at one particular frequency.

In reality all structures will have a multitude of vibration modes (as many as you want to look for) and each mode will have its natural frequency. Think of the many vibration modes in the head of a tympani used by a skilled percussionist to produce different notes. In general, (as opposed to the simple model of a vibrating string) the natural frequencies of the different nodes are NOT harmonically related.

In a tripod, a particular vibration mode will be troubling if it 1) is excited in the environment, 2) results in image motion and 3) is relatively undamped.

[Robert Opheim]

I too have been shooting in the NW forests for a number of years. I have had to deal with camera/tripod movement problems. First I discovered that my gitzo #3 studex center column and head caused movement - especially in wind. I purchased a #4 legs and a #5 3-way low profile head. This works better for vibration control for my technikardan and C-1 Calumet 8x10. I still am very careful with the center column - it is a cantilever and will move. I have on-going issues with legs slipping into - sand, snow, dirt, organic stuff - and need to make aluminum plates with center depressions or wrap around snowshoes etc. I have just been pushing the tripod legs in to the soil until there is adequate resistance. Leg vibration control seems harder. A technique I have used include hanging weight on the center post of the tripod. I would think also of dampening the mid-span of the legs with a tight weighted rope etc. I haven't had to deal with shooting a long exposure while set up in the middle of a rapidly moving stream but that would probably create more unique resonant vibration.
Many large format cameras are like kites in the wind and the camera itself moves in wind. I had an old 8x10 field camera, and a couple of view cameras that would easily move with wind. It didn't even get to the tripod legs vibrating in the material resonance.

[engl]

For me doing long exposures in urban settings, vibrations from roads is usually the biggest source of problems. I've been using an aluminium tripod in the past but recently bought a carbon fiber one. It is lighter and better better built which was reasons enough to get one, but I also hope it will do just a slight bit better at suppressing vibrations.

But I wonder, does making a carbon fiber tripod more rigid also result in making it transfer more vibrations from the ground to the camera? In other words, shooting next to a road, would you want a travel CF tripod or a heavy duty one?

[johnielvis]

adding mass makes it more prone to the longer frequencies that plague the ULF cameras...sort of turns the tripod/camera arrangement in to a spring so it "catches the wind" once and sways forever due to the large mass--it's like ahuge pendulum..or a push from the packard starts it swaying and keep it swaying....this will blur anything with a longer lens. you probably wouldn't be bothered by high frequency vibrations with LARGE cameras since the amplitudes are small compared to the film/acceptable blur circles, etc...

smaller cameras would be affected by the higher frequencies, since the lighter weights diminish the sway action---the larger magnifications in the film make the higher frequency vibrations with the smaller amplitudes more important---these are generally governed by stiffness of the tripod arrangement---generally this is totally geometrical depending on the tripod/camera--easiest way to eliminate it is to "tune it out"....so, change the SHAPE of the tripod--make it higher or lower---making it smaller will tune it to higher frequencies, but the amplitudes are small...basically just don't over-extend the tripod past the vibration limits imposed by the size of the magnification of the negative

in short more mass = more trouble for heavier, larger cameras---it makes it a "bigger pendulum" that wants to sway longer--more mass=more energy stored. you want to stiffen these up as much as possible to keep out the lower frequencies...you should be able to see the vibration by giving the camera a shove and see if it keeps moving...if it does...it's vibrating at a natural frequency...you can try to dampen this frequency by changing leg length or raising/lowering the center column (lowering it is best...the longer the center column, the longer the low frequency that it vibrates at.

smaller cameras generally don't have anything to worry about unless you hear something buzzing. you should be able to feel when you trip the shutter of a small camera if there's an impulse or something....actually---just GRABBING the tripod leg will change the stiffness right there--so that'll eliminate some frequencies too....

[Vaughn]

A friend was photographing upstairs in a large old wood building, about to be demolished...a large open space, and the building shook and swayed as trucks passed by on the street below. The highway still goes through the center of town.

Using a B&J 8x10 on a wood tripod, and long exposures in the dark interior, he was surprised how sharp his images were. The building may have shook, but the camera on its pod must have swayed right along with it.

Vaughn