stringscope
03-03-2007, 11:59 PM
Well it is an astrograph really.
The optics are owned by CAS and I understand have been in storage for a couple of decades. I have mounted the optics in a plywood alt/az mount so at least it can be used visually. It was a fun project, I am not sure how practical it is but it does work.
It is not yet complete. I have got it to a point where it is usable and I have then put it on a set of temporary wheels so at leat I can move it around the workshop. 2 items still to go; dew shield and retractable wheels. A little bit of info if you are interested:
Optics supplied by the US Navy Research Labs for use in a "Minitrack" satellite tracking camera.
System was in use by NASA at Orroral Valley until passed onto CAS in the mid 80's.
Camera used photographic glass plates 8"X10" => 11X14 degrees FoV.
Lens system appears to comprise 6 elements that are mounted in a turned steel tube. The objective cell unit is 220mm in diameter, 500mm long and weighs 26kg!!:eyepop:
Apeture is 200mm, focal length is 1000mm and there is an internal adjustable aperture stop allowing for a variable F ratio from F5 to F16.
Given the weight of the objective cell it has been a challenge to ensure the mount and tube are up to supporting the optics.
Given the poor weather we have been having I have only had limited opportunity to use it. From what I have seen so far, really nice for low power wide field views. However, as you push the power up the CA becomes dramatic. As might be expected a OIII filter changes the picture and it becomes tack sharp to the edge.
I can post more images if anyone is interested :) .
Cheers,
The optics are owned by CAS and I understand have been in storage for a couple of decades. I have mounted the optics in a plywood alt/az mount so at least it can be used visually. It was a fun project, I am not sure how practical it is but it does work.
It is not yet complete. I have got it to a point where it is usable and I have then put it on a set of temporary wheels so at leat I can move it around the workshop. 2 items still to go; dew shield and retractable wheels. A little bit of info if you are interested:
Optics supplied by the US Navy Research Labs for use in a "Minitrack" satellite tracking camera.
System was in use by NASA at Orroral Valley until passed onto CAS in the mid 80's.
Camera used photographic glass plates 8"X10" => 11X14 degrees FoV.
Lens system appears to comprise 6 elements that are mounted in a turned steel tube. The objective cell unit is 220mm in diameter, 500mm long and weighs 26kg!!:eyepop:
Apeture is 200mm, focal length is 1000mm and there is an internal adjustable aperture stop allowing for a variable F ratio from F5 to F16.
Given the weight of the objective cell it has been a challenge to ensure the mount and tube are up to supporting the optics.
Given the poor weather we have been having I have only had limited opportunity to use it. From what I have seen so far, really nice for low power wide field views. However, as you push the power up the CA becomes dramatic. As might be expected a OIII filter changes the picture and it becomes tack sharp to the edge.
I can post more images if anyone is interested :) .
Cheers,