How do I reduce tripod/camcorder vibration during mine blast videoing?

[GLeeM]

Problem: ground vibration from hard rock mine blast shakes tripod. How can I reduce effect to get better video?

I have been occasionally helping with this job at work for a while now and finally realised that maybe we have missed some basic ways of dampening vibration.

About nine years ago the boss said buy a camera and tripod and have at it. I knew very little about video and video cameras. We have used up maybe eight camcorders and several tripods. Camera loss due mostly to dust and then fly rock, some because tripod was not set well enough and it tipped or blew over (other people, not me).

To give you an idea of what our blasts are like here is a video of a soft rock blast that I would call a small puff.

We set the camcorder, currently a Sony HDV miniDV model (~$1,500), on a tripod (~$300) anywhere from 200 feet to 4,000 feet away from the blast pattern. The further away the less shake, but sometimes the only good view is from in close. The closer shot gives a better view of the holes going off, which is what we want to see. We must leave the camcorder recording and clear to 3,000 feet for our protection from fly rock. The camera is now protected from dust by an underwater housing and from fly rock, when in close, by a homemade stainless steel shell (looks like a rural mailbox).

Any technical/mechanical device recommended must be able to perform in very cold (-50 F) conditions.

Thanks in advance for any suggestions!

 

[soydios]

have you tried leaving the camera/tripod in or on a vehicle? those have damped suspensions, which is probably a good way to take care of any vibration. heck, even a golf cart would do.

 

[GLeeM]

Originally posted by: soydios
have you tried leaving the camera/tripod in or on a vehicle? those have damped suspensions, which is probably a good way to take care of any vibration. heck, even a golf cart would do.

Good idea and when possible I will test it. Problem is that vehicles and other mining equipment has to be at least 1,000 feet away and it is not very often that the ideal view is from a place that a vehicle can get to. Also, it would take two people to do the job then as I would need an escape vehicle to get into the clear after starting the camcorder.

Any other ideas or a suggestion on a different forum that might have more tips?

 

[Fardringle]

How about a kids' wagon (like a Radio Flyer) with large wheels? I saw one at Walmart the other day with ATV style wheels and small spring shocks. It was only about $25 if I remember right, and it would give some insulation from ground vibrations. It's certainly not a "pro" solution but it might work. You could make a really good system by stacking to platforms (like wooden pallets) separated by gas shocks or springs to help insulate the top layer from ground movements but I like doing things the easy way so I'd give the wagon or something similar a try.

 

[DrPizza]

I looked at the video a few times and was wondering if perhaps there might be a software solution. Find some object that doesn't move with respect to the camera, and simply crop with respect to that object. Enlarge the field of view slightly to compensate for the loss in the video. Heck, if you needed to, you could even put something into the foreground to use for this purpose - a little round circle of paper with a bright red dot on the center of it or something.

I've done very little video editing, so I don't know what sort of software is available for something like that.

 

[soydios]

yeah, you could either use hefty hardware or software image stabilization.

the key with using a stabilized platform is that it must be damped. if it's only supported by springs then it will bounce along for a good while. springs and dampers (car and golf cart suspensions) would damp it fairly quick.

you sure you can't get a junker golf cart with a working suspension? you can tow/haul/push it into position, and then put a tripod on it.

 

[otispunkmeyer]

for software have a look at ProDAD's Mercalli, it seems to work quite well

Barring that you could purchase a Hand Held SteadiCam System such as the Tiffen Merlin, or one of the GlideCam Models. Those are relatively cheap compared to full on steadicams. i have tried a full steadicam and its just serene the way you can go almost anywhere with it, without a hint of shake.

im currently designing my own hand held steadicam. basically it just works on increasing the mass moment of inertia to damp out the vibrations. vibration damping is quite (or can be) quite complex, but put very simply F=MA..... for the same excitation force, a heavier mass will experince less acceleration than a smaller mass. ie it takes more force to accelerate (shake in this case) the heavier object.

Google Home Built Stabilizers, its a good forum and many there have gone and made their own stuff.

sticking with mechanics, you could try mass damping. if you know the range of vibration due to the explosion and your only going to use the same camera, i reckon it'd be possible to construct a mass damping device that will absorb all the vibration for you. you'd have to work it all out, and it may end up that it'd need to move a lot due to high vibration amplitudes... but you never know, it might not.

i think a SteadiCam would be the way to go, with a vest and isolating arm, it should be immune from most of the vibration

have a dig here for some videos of what these things can do http://www.glidecam.com/videos.php

 

[chucky2]

What about hanging a weight underneath the tripod to weight it down a little, and then mounting the tripod legs in some kind of gel where the tripod legs are suspended in the gel?

Or, if you wanted to get really created, mount it on a truck bed as stated but have a skid or something with magnets on it at the tripod legs, and then on the tripod legs, mount plates with magents again. That way you'd basically have the tripod floating.

If you somehow could pull off the gel and magnet thing, on a truck of minivan bed, I'd think you could get rid of most vibration problems that way...

Interesting problem given the shocks the tripod gets...

Chuck

 

[DrPizza]

I asked my son earlier today (He's been taking an independent study video editing class for 3 years now.) He mumbled something about something or other (sorry!), all I could figure out from listening to him was "yeah, no problem." So, a software solution does seem rather viable, if my son is correct.

 

[jpeyton]

I don't know if anyone suggested this already, but you could mount the tripod on a helicopter in-flight. That should almost eliminate any vibration felt at ground level.

 

[soydios]

Originally posted by: jpeyton
I don't know if anyone suggested this already, but you could mount the tripod on a helicopter in-flight. That should almost eliminate any vibration felt at ground level.

that would introduce vibrations and excessive noise from the helicopter, and be extremely dangerous while flying 300 feet from a large explosion. just my thoughts.

 

[LikeLinus]

look into building or buying a steady cam setup.

http://www.bhphotovideo.com/c/...GPK_Arm_And_Vest_.html

One example. They go up to and over 10K though

EDIT: The camera shake is actually cool in this instance. It shows the sheer power of the blast and looks like something that hollywood has to mimic!

 

[GLeeM]

Thanks to all for the great information!

Problem with hand held is that people must be at least 3,000 feet away and the ground shake is not as much concern from that distance. If the best view was that far away all the time we wouldn't have a problem, but like I stated above, sometime we leave the camera as close as 200 feet, usually, about 500-1,000 feet away and the ground shake is worse the closer you get. Would a stedicam device work if mounted to a tripod? Seems like it is to steady hand held.

I didn't know about software solutions, thanks for that info. Might have to give that a try.

Thinking about the software solution, I came up with an idea. What would the result be if I just deleted the worst frames? The ones with so much motion that everything is just a blur?

EDIT: As far as a helicopter goes, we already have a small plane in the air for every blast when the weather allows and have tried filming from it. That has it's own set of problems :roll: and if there is NO where to set up on the ground we do it from the plane. The plane must be outside the 3,000 foot circle (even if it is 2,000 up), the more zoom the harder to hold steady, the harder to find the blast pattern in the viewfinder. The time I tried it the thermals were throwing the plane up and down by ten foot leaps in a second, I missed the shot

 

[Texun]

My first thought would be to suspend the camera above the ground in some way..... maybe from a stable object with an extended arm from which you could suspend the camera with some sort of elastic cord. Maybe a tree limb? You would still probably have some swing to deal with but the sharp vibrations should be reduced through the elastic cord. Take a tree limb or similar steady object, hang the camera from the elastic cord, and then add a length of cord below the camera and attach a weight at the bottom. That might help reduce the swing motion.

You have an interesting project!

 

[gsellis]

A steady rig will not work. While you can 'rest' it (the sled - the arm attaches to the jacket) and usually do on a tripod type device to take the weight off or make adjustments, that is not how it works. You have the arm that isolates the motion and the smaller rigs use 'guiding' from the operator. They are very sensitive to wind as it blows the counterbalance mast. The overpressure, that is also part of the issue, will knock it way off and start it swinging.

An active rig might work, but the one I remember is about $70k and really is for continual motion.

ProDad Mercalli is kick butt and cheap. I have it and it is the fastest, most accurate tool I have next to the Glidecam.

Have you tried Eggcreate foam? Servers ship with tons of it, so some IT buds might be able to donate some squares. Maybe even memory foam? Might reduce the shake and a bungie here and there might stabilize it on the foam?

PS - Join DVInfo and post your question here too. DVInfo Steady rigs section We have a couple of manufacturers, home builders, industry flyers, and camera nuts that may have some other ideas including those that they have done for effects departments.