May 17th, 2008, 08:58 AM | #1 |
New Boot
Join Date: Mar 2008
Location: St Paul, MN
Posts: 12
|
Tripod Isolation from Ground Vibration
I shoot train movements close to trackside and notice image "instability" when I'm taping near rough track. Obviously this is vibration passed to the camera through the tripod so I'm looking for some way to isolate the tripod from the ground while maintaining stability. Is using one of those "beanbags" under each leg a possibility or does someone manufacture a foam product for this purpose? Thanks for any guidance.
|
May 18th, 2008, 12:19 PM | #2 |
Trustee
Join Date: Jun 2006
Location: Burbank
Posts: 1,811
|
First, use a tripod made of wood. (Carbon fiber and basalt/fiber glass are better than metal.)
There are the Meade vibration isolation pads: http://www.astronomics.com/main/prod...product_id/895 Read paragraph 2 of this article for some typical ways to dampen ground vibrations: http://www.pietro.org/Astro_C5/Mods/tripod_tray.htm Here are some ideas: http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00BXbT |
May 18th, 2008, 12:31 PM | #3 |
Inner Circle
Join Date: Dec 2002
Location: Augusta Georgia
Posts: 5,421
|
It would be interesting to determine if the Meade Vibration Isolation pads help or not.
Depending on your tripod, I would first hang a heavy weight from the top of the tripod legs. My Sachtler Speed Lock II legs have a hook for this purpose. This hook is also used to secure the tripod such as when working on a dolly.
__________________
Dan Keaton Augusta Georgia |
May 18th, 2008, 01:12 PM | #4 |
Major Player
Join Date: Jan 2007
Location: New York City
Posts: 523
|
Having some experience here (www.vimeo.com/user390555/videos youtube.com/user/ynda777) I don't think there is a solution here. The forces involved are just too great. The best you could do is keep steadyshot on and correct any pans in post.
The Meade things are designed for minimizing small vibrations--not the rather huge excursions you're talking about. I'd love to be proven wrong of course. Hanging a weight is only going to increase the 'coupling' which is exactly what you don't want.
__________________
Andy Tejral Railroad Videographer |
May 18th, 2008, 08:48 PM | #5 |
Inner Circle
Join Date: Jan 2004
Location: Miami, FL
Posts: 2,933
|
I wonder if a couple of those yoga mats would do the trick, or something similar. The material is kind of like rubber, so it should reduce the vibrations. I agree that hanging weight isn't going to help, but rather hurt the situation since you're dealing with some nasty vibration.
You might consider using a stabilizer instead of a tripod for the shots, that way your body would eat up all of the vibration. |
May 18th, 2008, 10:10 PM | #6 |
Trustee
Join Date: Jun 2006
Location: Burbank
Posts: 1,811
|
How about setting up in the back of a pickup or the top/hood of a car. The tires should absord most of the vibration?
I don't know if this idea would work, but it would be easy to test. |
May 19th, 2008, 01:00 AM | #7 |
Inner Circle
Join Date: Feb 2004
Location: switzerland
Posts: 2,133
|
you can build a platfom with two plywood plate and some tennis ball sandwiched in between.
|
May 19th, 2008, 03:38 PM | #8 |
Major Player
Join Date: Feb 2007
Location: Denver/Vail Colorado
Posts: 254
|
Andy - can you explain your "coupling" comment?
|
May 19th, 2008, 05:39 PM | #9 |
Major Player
Join Date: Jan 2007
Location: New York City
Posts: 523
|
I'm not sure but here goes: The more weight you have on the tripod, the more the tripod is going to 'be one with' the ground. The force pulling down firmly connects the tripod to the ground. A lighter tripod is easier to tip over, less connected to the ground.
If you are trying to eliminate wind vibration, that is good--generally the ground doesn't move unless you're in earthquake country, which is essentially what we're talking about here--mini, repetitive earthquakes.. The force of the train literally moves the ground so you want the tripod 'to be separate from' the ground. Did that help?
__________________
Andy Tejral Railroad Videographer |
May 19th, 2008, 05:46 PM | #10 | |
Major Player
Join Date: Oct 2007
Location: Paradise, california
Posts: 353
|
Quote:
wrong? maybe?
__________________
"What I need is an exact list of specific unknown problems we might encounter." |
|
May 19th, 2008, 05:55 PM | #11 | |
Major Player
Join Date: Jan 2007
Location: New York City
Posts: 523
|
Quote:
Picture a train, specifically a North American freight train. Each car has a 'truck' at either end so the weight of two cars is clustered together. I guess, if you shot the nearest part of the train, yes, the motion of the ground would be very close to the motion of the train. But generally, you want a variety of shots, no? Say a long shot down the length of the train. Worse, make it a telephoto shot--more susceptable to vibration. The movement of the train is an inch or two and will not be apparent once you get 100' or so from your location. But move the lens that much and you'll notice a definate jiggle in the image.
__________________
Andy Tejral Railroad Videographer |
|
May 19th, 2008, 07:34 PM | #12 |
Major Player
Join Date: Feb 2007
Location: Denver/Vail Colorado
Posts: 254
|
I see what you mean - but is that a valid analogy? Vibration will often cause secondary movement, which, in lighter objects amplifies the movement. In this case surely a heavier tripod would be more stable. Being securely coupled to the ground is better than bouncing around on top of it.
|
May 21st, 2008, 10:48 AM | #13 |
New Boot
Join Date: Mar 2008
Location: St Paul, MN
Posts: 12
|
Tripod Isolation from Ground Vibration
Thanks for all the ideas. I going to investigate those Meade Anti-Vibration Pads. Turns out B&H has them in their Summer 2008 catalog on P. 458 in the Optics section.
Thanks again for the ideas. |
May 21st, 2008, 06:53 PM | #14 |
New Boot
Join Date: May 2008
Location: Stratford CT
Posts: 14
|
Please let us know what you think of the pads.
|
| ||||||
|
|