|
|||||||||
|
Thread Tools | Search this Thread |
December 13th, 2006, 03:32 PM | #1 |
Major Player
Join Date: Nov 2006
Location: London, UK
Posts: 321
|
"The poor man's steadicam" for HV10?
Hi chaps
Just wondered if anyone has seen "The poor man's steadicam" for $14 http://www.cs.cmu.edu/~johnny/steadycam/ I was wondering how well it work with the hv10 (the HV10 is fairly small and lightweight)? You can order the kit to the UK for around $50 I really like the example videos on this page: http://littlegreatideas.com/steadycam/ I also noticed that Jason Bradbury did something similar for the gadget show: http://www.jasonbradbury.com/jason_b...eadicam_c.html Any views would be welcome Fergus Last edited by Fergus Anderson; December 14th, 2006 at 10:53 AM. |
December 13th, 2006, 06:11 PM | #2 |
Major Player
Join Date: Nov 2005
Location: Grand Rapids, MI, USA
Posts: 202
|
There was a discussion about this in other dvinfo subforums, I don't remember where.
The upshot is that the side-handle only adds more vibrations, and that the piping should be PVC, not metal. Steel piping only adds excessive weight to the system, what stabilizes the rig is the counterbalance at the bottom and holding the rig at the neutral point. I don't think it makes sense to order this kit at all, especially if you have some sort of home improvement or hardware store near you. That Jason Bradbury system looks a lot better. |
December 13th, 2006, 06:59 PM | #3 |
Regular Crew
Join Date: Oct 2006
Location: Nanuet NY
Posts: 74
|
The link posted above seems to be missing the final 'l' in 'html.' This one works for me:
http://www.jasonbradbury.com/jason_b...eadicam_c.html Can't say that I really understand Jason Bradbury's device. He refers to attaching a mini-tripod as a handle using a Jubilee clip. But I don't know what a Jubilee clip is, and can't see it in the photo. In the horizontal row of three photos embedded in his text, what is shown in the center photo, where he is adjusting a black knurled wheel with his fingers? In the right-hand photo, where is the "tiny Casio palm TV" mentioned in the text? And what is the silver thing with a wire hanging off it, located in front of his belly button? Frankly I like the PVC pipe concept better. |
December 13th, 2006, 08:02 PM | #4 |
Trustee
Join Date: Nov 2005
Location: Honolulu, HI
Posts: 1,961
|
Just put a wood (yes, wood) crossbar on a monopod with weights at each end. I find about a 24" crossbar to be the minimum and 30" would probably be a functional maximum. Have the crossbar mount on the bottom of the first (top) section of the monopod. It should be rotated so it points behind you to the right and in front of you to the left, assuming a right-handed operation. This helps prevent it from bumping you. Use wood or something similar as this is a very light material for it's rigidity. Rigidity is critical. Plastic pipe is too flexible and metal pipe is too heavy. The only weight that matters is weight far out on the ends of the crossbar. Fiberglass or carbon fiber tubing at least 1" in diameter should work. Wood is easier to mount as you can cut into it part way without ruining it's rigidity. I used an oak 2"x2" but I think mahagony would be better as it is less prone to splitting. Hold the monopod at, or barely above, the center of gravity. Email me if you are serious about building one of these.
|
December 13th, 2006, 08:03 PM | #5 | |
Major Player
Join Date: Sep 2006
Location: London UK
Posts: 376
|
Quote:
Try carrying a full bag of builders cement and see how hard it is to shake around. Here is my old steadicam, built from junk: |
|
December 13th, 2006, 08:35 PM | #6 | |
Major Player
Join Date: Nov 2005
Location: Grand Rapids, MI, USA
Posts: 202
|
Quote:
|
|
December 14th, 2006, 06:23 AM | #7 |
Major Player
Join Date: Nov 2006
Location: London, UK
Posts: 321
|
Thanks chaps
Well I would really like to build one but my DIY skills are somewhat lacking (!!) which is why the idea of ordering the kit sounds appealing. Having never used a steadicam before I'm finding it difficult to visualise how it will work and what benefit wood or plastic would have over metal? I thought the heavier the better especially as its a tiny lightweight camcorder? |
December 14th, 2006, 07:32 AM | #8 |
Regular Crew
Join Date: Oct 2006
Location: Nanuet NY
Posts: 74
|
In engineering or physics terms, what the steadicam attempts to maximize is the moment of inertia; that is, inertia with respect to angular rotation. The formula is I = mr2 , where I = inertia, m = mass, r = radius from the axis of rotation, and 2 = squared (should be superscripted).
If you consider the handle as the axis of rotation, then adding (say) 10 lbs of weight at the handle would have no effect on the moment of inertia. You would have to support the extra weight with your arm, but it would not increase the resistance to rotation at all. By contrast, weight added at the extreme ends (at the camcorder on top, or the counterweight at the bottom) adds inertia most effectively, because the radius is the largest possible within the physical dimensions of the unit. Ideally, you would like to maximize the moment of inertia while minimizing the overall weight. This is best done by having all the weight concentrated at the extreme ends, and none at the center or in between. Thus if a kind of pipe having great strength but little weight can be used for the structure, it will yield the greatest moment of inertia for a given total weight. In principle, a hollow member accomplishes this task better than a solid one. Thus PVC pipe, if its diameter and wall thickness are sufficient to make it rigid enough, could be a good choice. Aluminum tubing could be effective also. Wood as mentioned above is quite strong for its weight, though not hollow. Steel pipe is less effective, because it adds so much weight near the center of the device, where it does no good for resisting angular rotation. |
December 14th, 2006, 08:17 AM | #9 |
Regular Crew
Join Date: Oct 2006
Location: Nanuet NY
Posts: 74
|
Here's a good, mostly non-technical explanation of the principles which underlie the Steadicam. The homebrew units we're discussing don't have an articulated arm. But the section titled "Spreading the Camera's Mass" is entirely pertinent.
http://kiwifilm.com/steadfaq.html#A1 |
December 14th, 2006, 09:47 AM | #10 |
Trustee
Join Date: May 2005
Location: Saint Cloud, Florida
Posts: 1,043
|
That poor man's steadicam
I have the VX2100 and now the A1U. I ordered that poor man's steadicam from the Little Great Ideas site. Mainly ordered out of curiosity, it arrived quickly about a month ago. Last Friday I actually got to use it for more than testing. For 5 hours I walked around with that steadicam attached to my VX. I was TOTALLY satisfied with how well it (and I) held up. The footage taken with it was amazingly steady and is producing some great comments from those that have watched it. I recommend it. I also plan on duplicating its design in aluminum or something a little lighter.
PROS: Steady but still easy to move around Changeable to several different configurations for all sorts of angles Cheap and mod-able Virtually indestructable Compact Can be used as a mono-pod as well Handy in a bar fight ;-) CONS: Heavy, after 5 hours I was a little sore (but I'm out of shape too) Ugly, has that industrial look to it, lol (paint it) Side handle needs to be about half the length or just removed
__________________
www.facebook.com/projectspecto |
December 14th, 2006, 10:55 AM | #11 |
Major Player
Join Date: Nov 2006
Location: London, UK
Posts: 321
|
Thanks Marco - sounds great - will there be any difference attaching the HV10 to it?
I got the price wrong though if anyone else is interested - is $92 to the - still about £50 which is pretty good. |
December 14th, 2006, 10:59 AM | #12 | |
Trustee
Join Date: May 2005
Location: Saint Cloud, Florida
Posts: 1,043
|
Quote:
HV10, hmmm. I wouldn't think there would be, it will surely fit since its smaller than a VX2100 or the Sharp 8mm I've used on it.
__________________
www.facebook.com/projectspecto |
|
December 14th, 2006, 12:37 PM | #13 |
Major Player
Join Date: Nov 2006
Location: London, UK
Posts: 321
|
just found this:
http://www.hack247.co.uk/2006/07/31/...a-steadicam-4/ its a ten minute tutorial video on how to build the $14 steadicam |
December 14th, 2006, 05:39 PM | #14 |
Trustee
Join Date: Nov 2005
Location: Honolulu, HI
Posts: 1,961
|
"Ideally, you would like to maximize the moment of inertia while minimizing the overall weight. This is best done by having all the weight concentrated at the extreme ends, and none at the center or in between. Thus if a kind of pipe having great strength but little weight can be used for the structure, it will yield the greatest moment of inertia for a given total weight.
In principle, a hollow member accomplishes this task better than a solid one. Thus PVC pipe, if its diameter and wall thickness are sufficient to make it rigid enough, could be a good choice. Aluminum tubing could be effective also. Wood as mentioned above is quite strong for its weight, though not hollow. Steel pipe is less effective, because it adds so much weight near the center of the device, where it does no good for resisting angular rotation." You have the idea right, but you must make sure to have weight at three seperate points. The crossbar on the monopod accomplishes this since the camera is one point of weight. PVC pipe could work except that it is not rigid enough until it gets big. Wood is not best because it is stronger, but that it is more rigid. Except for a carbon fiber or aluminum tube, wood or bamboo is the most rigid substance for it's weight. Wood is also easy to work. The weight of a system like this is why using a monopod is such a great idea. You can remove the weight from your arm every time you stop. With practice, you can move around with the monopod foot inches from the ground without bumping anything. Don't put the weight too low or it will hit your knees. This is why I put the weight at the bottom of the first monopod section. This keeps it above waist level. Here are some instructions for building a crossbar: Get a section of 2x2 strong lumber with no knots. Mahogany is best. An easy way to make a crossbar that will clamp onto the monopod and be easily removable is to make two sections about 28-30" long. Cut a v-notch about 3-4" from each end. Clamp the two pieces together so the notch makes a diamond/square pattern. The two notches make the hole where the monopod will be clamped. To make the clamping force, drill bolt holes about two inches away from the hole all the way through both crossbar sections. You will need to go to the hardware store with the rig to get bolts just the right length. I used 3/8" thick bolts with large wing nuts and washers to hold my rig together. I used 1lb. lead scuba weights at the end, but you can use just about anything as long as it is smooth or covered by something so it won't bump and damage people or objects. |
December 14th, 2006, 10:09 PM | #15 | |
Trustee
|
Quote:
|
|
| ||||||
|
|