81 replies to this topic

[vietspace]

Rhomboid prism & my auxiliary telescope

 

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[vietspace]

My auxiliary telescope

Edited by vietspace, 19 May 2019 - 11:52 AM.

[vietspace]

 

A reticle paper at the focal plane of CPC 11in

 

[shredder1656]

IMG_0168.JPG

 

I almost finished my collimator
Today I received a 3-9x40 rifle scope to make the auxiliary telescope, but it’s too long and heavy so it's too difficult to stabilize behind binoculars eyepiece

Anyway, I think I have all things to complete my collimator. In the next few days I will complete the test stand and consider whether I can replace a lighter auxiliary telescope.

 

I use a Celestron CPC 11in for collimator tube with a reticle at focal plane
Rhomboid prism ~ 50 usd from a Vietnamese optical company
A Vixen Az-Alt adjustment for Test stand

 

 

Rhomboid prism & my auxiliary telescope

 

 

IMG_5196.JPG

My auxiliary telescope

 

 

IMG_6580.JPG

 

A reticle paper at the focal plane of CPC 11in

Nice work!!!  

 

I knew someone would get one put together.  I just need TIME.  This contraption is not that difficult.  Bill did everyone a favor by offering these tricks and details to the masses, in my opinion.  I will post pics when mine is done too.  

 

Nice work with the aux scope.  Keep at it!

[Ant1]

Hi

 

From your picture in post #75 I'm not sure how your mounts are attached to the table?

Be careful that any movement of the binocular support relative to the telescope will ruin your efforts.

I have myself wasted some effort trying to troubleshoot such a setup before realizing target and binoculars were drifting relative to each other during the collimation process.

 

Regards,

Ant1

[vietspace]

Hi

 

From your picture in post #75 I'm not sure how your mounts are attached to the table?

Be careful that any movement of the binocular support relative to the telescope will ruin your efforts.

I have myself wasted some effort trying to troubleshoot such a setup before realizing target and binoculars were drifting relative to each other during the collimation process.

 

Regards,

Ant1

Sure, Ant1.

I only used the camera tripod to check auxiliary scope function.
The next day, I will make a stable test stand based on the Vixen Az-Alt adjustment.

[Gordon Rayner]

I   have  used 5 x 20    golf scopes   as auxiliary  telescopes,   combined with JTII  beam combiners  or equivalents,  for Navy-style   use.   5X is   a bit  high for rapid  freehand use,  but motion  damping  elbow  pads on   an armrest  can help.  I made adapters  for Navy (1923)  3X  auxiliary  scopes  to   JTII  and  to   other,   approximately  equivalent ,  rhomboidal   beam combiners.     Search  "Dinka"  and /or "Nuer"  for pictures  .

 

Hanna  in ATM II or III   shows   a mounted  Navy  style  auxiliary scope  with peek-around rhomboid  attachment.   Freehand was  common practice   among Navy  OMs.   During WW II,  Hanna and his crew work closely with  the Mare Island  optics repair  people.    ?????

 

Golf scopes can be used  to measure the  angular sizes  of   features of   real or simulated  distant targets.    To convert   golf hole ranges  on  its  reticle  to  angular  quantities,  use a military or  nautical  binocular with   a  mil scale   in one eyepiece, a transit, or a theodolite  from a friendly surveyor.   A little bit   of  easy   trigonometry  might be  useful,  if needed.    

IIRC,  the golf scope    reticle  ranges   use   hole  marker pole  height  as a constant  (??).