Re: Newbie with questions

[P3D John W Roberts <roberts@xxxxxxxxxxxxxxxxx>]

>Date: Wed, 12 Mar 1997 08:46:07 -0600
>From: P3D Paul Albers <PAlbers@xxxxxxxxxxx>
>Subject: Re: Newbie with questions

>P3D Grant Campos' wrote:'
>> 
>> Start with a tall rocket with a wide enough body to hold cameras in the tube.
>> Attach one camera (looking outward through the side of the rocket body, 
>> perpendicular to the axis of the rocket) near the tail of the rocket and 
>> the other (also looking out through the body of the rocket, perpendicular 
>> to the axis of the rocket) near the tip.  
>> That way they will be firmly oriented correctly with respect to each other.  
>> Then set up the parachute to carry the rocket horizontally, with the cameras 
>> pointing at a slight angle from straight down, as it floats down.  The cameras 
>> will then be horizontal and at a fixed distance from each other.  Then have the 
>> camera set to take pictures a few seconds after the body of the rocket 
>> is horizontal, after the decent has stablized a little bit.

>Yes, that's the basic idea I would like to implement, although I would
>rather have a beam splitter built into the body tube of the rocket. So,
>for the third time:

>Can a 1/2 decent beam splitter be home-built?  has anyone done this and are
>there any plans for doing this available?

At the interocular you're talking about, and with a reasonable lens focal
length and aperture, the mirrors would have to be a foot to several feet 
across. That must be some incredibly fat body tube!

Also, if you have any optics near the bottom of the rocket, you have to
be concerned about what the exhaust and ejection charges will do. I once
built a model rocket with a transparent plastic tube for the body. One
flight, and it had an opaque tube (well, maybe translucent) - the ejection
charge had completely coated the inside of the tube with soot!

Maybe you can have a smaller tube inside the body to direct the ejection
charge - but that gets in the way of any photographic equipment you want
inside the tube. Maybe you can use a design with no ejection charge - after
burnout, it just flips over horizontally and glides into the next county.

John R


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