Naked Science Forum

Non Life Sciences => Technology => Topic started by: imatfaal on 17/08/2011 17:10:49

Title: How would you damp a camera?
Post by: imatfaal on 17/08/2011 17:10:49

I am thinking of making a knock-off / el-cheapo steadicam and curious what amount of damping to aim for?  Any suggestions? 

I already have a very basic handmade steadicam (uj and semicircular weighted bit) - but fancy adding a bit of damping for the vertical movement of walking.  I presume that I should aim for critical damping - but any ideas/knowledge would be greatly appreciated. 

Title: How would you damp a camera?
Post by: SeanB on 17/08/2011 18:47:03

Normally damping is done with grease.

Title: How would you damp a camera?
Post by: Geezer on 17/08/2011 19:02:50

Some sort of fluid friction would probably be best. Air or liquid would work. You'll want to be able to tweak the amount to match whatever you use for a spring.

You might try a modified bicycle pump, or some sort of piston/cylinder arrangement with an adjustable port in the piston.

Title: How would you damp a camera?
Post by: CliffordK on 18/08/2011 06:52:54

How big of a device are you building?  A gyroscope would help you with rotational dampening, although you would have to be careful not to introduce a vibration.

I would assume some steady-shot features are software driven, but I'm having troubles imagining how that would work.  Perhaps combine line and feature recognition with super-high-speed imagery, and merging the multiple frames to improve resolution or image quality.

Title: How would you damp a camera?
Post by: Geezer on 18/08/2011 07:07:32

It turns out the pros don't use any damping on theirs. What you need is a "constant force spring".

(What he on about now! Constant force my arm!!)

http://en.wikipedia.org/wiki/Iso-elastic

Title: How would you damp a camera?
Post by: imatfaal on 18/08/2011 09:27:16

Gaeser - thanks for that, perfect!   I had assumed that I could see only part of the assemblage on the professional ones - but that something was missing.  But I just wasn't thinking straight Should have looked at my desk lamp!! Not sure I can bodge something together that is better than my current super lo-tech version - but got to give it a go.  I was thinking of a simple piston with small holes and a spring to create fine adjustments.
 
Sean - a simple rod pushing/pulling through grease was my other thought, but to be honest I could not see how to keep it clean and contained without proper engineering.

Clifford - I knew that the original steadicams - take a look at this beautiful excerpt  Raging Bull  (http://www.steadishots.org/shots_detail.cfm?shotID=236) were almost entirely mechanical.  A friend of the family allowed me to use one when I was about 11-12 - it cost more than his or my fathers car! 

Thanks for all you ideas - good stuff indeed

Title: How would you damp a camera?
Post by: qazibasit on 29/08/2011 14:16:09

use honey, thats the best u will get out there