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Has anyone built one of these collimators or...?

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#26 Ant1

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Posted 25 March 2019 - 12:55 PM

Hi

Yes any decent telescope will be perfectly suited to the task.
I use a retired 12 inch newtonian reflector with a mirror in need of recoating and it works great

Regards
Ant1

Edited by Ant1, 25 March 2019 - 12:56 PM.


#27 MartinPond

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Posted 25 March 2019 - 03:39 PM

This is interesting.

So far, nobody has been able to make and photograph

   this 'simple' device, and there is a lot of speculation about the

   parts you might use.

Hopefully, somebody will make something work...


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#28 Mad Matt

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Posted 25 March 2019 - 03:51 PM

I just tried to glue two porro prisms together to make a rhombus prism. Unfortunately I was not able to line them up perfectly and I can’t get the overlapping images to merge 😳 Looks like I will have to invest in a „real“ rhombus.

I just thought I would pass that along in case any one also has the same idea.

#29 shredder1656

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Posted 25 March 2019 - 07:23 PM

I am making a little progress, but nowhere near ready to even assemble it, let alone show pics.  I will when I get there, though.  

 

I was fortunate enough to be connected to the author of the book.  I highly recommend grabbing it while you can.  I think anyone with a bit more understanding of all of these topics will fly through it with no issue.  Meanwhile, Bill sent this info to me and requested that I pass it along.  He thought it might clarify some of the topics we have brought up.  Enjoy!  I did.  

 

Attached File  CN Collimation Manifesto 190325.pdf   161.98KB   125 downloads

 

 


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#30 Mad Matt

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Posted 26 March 2019 - 12:22 AM

I am making a little progress, but nowhere near ready to even assemble it, let alone show pics.  I will when I get there, though.  

 

I was fortunate enough to be connected to the author of the book.  I highly recommend grabbing it while you can.  I think anyone with a bit more understanding of all of these topics will fly through it with no issue.  Meanwhile, Bill sent this info to me and requested that I pass it along.  He thought it might clarify some of the topics we have brought up.  Enjoy!  I did.  

 

attachicon.gif CN Collimation Manifesto 190325.pdf

 

When you talk to Bill the next time thank him for the correction. Yes, I overlooked the word Celestron in the sentence. The point is the same... As Bill stated, essentially any telescope large enough to provide collimated light to both sides of the binocular will work.



#31 vietspace

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Posted 27 March 2019 - 02:01 AM

I just tried to glue two porro prisms together to make a rhombus prism. Unfortunately I was not able to line them up perfectly and I can’t get the overlapping images to merge Looks like I will have to invest in a „real“ rhombus.

I just thought I would pass that along in case any one also has the same idea.

I have seen Auxiliary Telescope on the Facebook of Suddarth Optical Repair. I'm curious if they sell this or not? I sent a message to ask them but have not yet received an answer.

 

Screen-Shot-2019-03-27-at-1.52.41-PM.jpg


Edited by vietspace, 27 March 2019 - 02:04 AM.

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#32 SandyHouTex

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Posted 27 March 2019 - 09:29 AM

So earlier this week I ordered Bill's new book from Amazon:

 

https://smile.amazon...0?ie=UTF8&psc=1

 

It's actually better at describing how to put together a reasonably priced collimator, including the binocular fixture, etc.  It's a very good read if you want to do that.


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#33 MartinPond

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Posted 27 March 2019 - 07:18 PM

I have seen Auxiliary Telescope on the Facebook of Suddarth Optical Repair. I'm curious if they sell this or not? I sent a message to ask them but have not yet received an answer.

 

attachicon.gif Screen-Shot-2019-03-27-at-1.52.41-PM.jpg

Nice...

 

Looks like someone has looked at the Navy Manual and used

   a 3x auxiliary telescope here:

 

https://www.instruct...th-Collimation/

 

I think he's just doing a "conditional" job though.  He's happy..

Got his 20x50 Siam Cat purring.

 

 

A longer-fl eyepiece from a 7x50 (~28mm)  with the objective from an 8x25 pair (~90-100mm)

  might make a nice aux. telescope.  (2 pairs to make 1 pair)

Fixturing/mounting  it in just right is the  trick)..

 

Or:    3x gunsight!


Edited by MartinPond, 27 March 2019 - 07:26 PM.

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#34 SMark

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Posted 27 March 2019 - 08:26 PM

I have seen Auxiliary Telescope on the Facebook of Suddarth Optical Repair. I'm curious if they sell this or not? I sent a message to ask them but have not yet received an answer.

 

attachicon.gif Screen-Shot-2019-03-27-at-1.52.41-PM.jpg

You see 4 of those in the picture. But Cory made 5 total. Take a wild guess who insisted on having the first one for himself... coolnod.gif


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#35 SandyHouTex

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Posted 28 March 2019 - 08:45 AM

I have seen Auxiliary Telescope on the Facebook of Suddarth Optical Repair. I'm curious if they sell this or not? I sent a message to ask them but have not yet received an answer.

 

attachicon.gif Screen-Shot-2019-03-27-at-1.52.41-PM.jpg

Yes.  Cory makes a batch and then sells them.  I think for around $500 or $600 if I remember right.


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#36 vietspace

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Posted 28 March 2019 - 09:37 PM

Yes.  Cory makes a batch and then sells them.  I think for around $500 or $600 if I remember right.

So "cheap"!

I found a small optical company in Vietnam, they can help me make a custom rhomboid prism that I designed as shown in the picture. 

Hope I can build an auxiliary telecope by myself

54433051_321972815335017_4684088730267418624_n.jpg


Edited by vietspace, 29 March 2019 - 04:55 AM.

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#37 Mad Matt

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Posted 29 March 2019 - 12:45 AM

So "cheap"!
I found a small optical company in Vietnam, they can help me make a custom rhombic prism that I designed as shown in the picture.
Hope I can build an auxiliary telecope by myself
54433051_321972815335017_4684088730267418624_n.jpg


Make sure the 45deg faces are absolutely parallel with each other like within 10 arc seconds. That is critical as any variation will result in collimation errors.
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#38 shredder1656

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Posted 29 March 2019 - 03:38 AM

I have not made much progress on this project, but have spent more time breaking binos that I was trying to fix.  flame.gif  I did have a quick chat with Bill and received some further clarification.  

 

I hope it helps anyone on here who needs it

 

 

 

 

 

 


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#39 SandyHouTex

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Posted 29 March 2019 - 10:29 AM

I purchased a cheap Cabela’s rifle scope and a cheap prism from China on ebay.  I plan to make an adapter to hold the prism that slides on the front of the riflescope.  I bought the prism from China because it was the only one I could find long enough to fit my needs.



#40 SMark

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Posted 29 March 2019 - 02:16 PM

Cory sent me some illustrative pics that should help the discussion...

 

 

Eric Suddarth on the Mark 5...

Attached Thumbnails

  • 2445F4BD-92A2-4403-977F-AA72CBE3BC13.JPG
  • IMG_1593.JPG

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#41 SMark

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Posted 29 March 2019 - 02:20 PM

This is what Mark 5 collimation looks like. Transfer coordinates observed in minimum ipd (A) and max ipd (B) then solve clockwise to locate new position ©. This is the new position where you manipulate the optics to. Always clockwise!

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#42 SMark

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Posted 29 March 2019 - 02:21 PM

Daughter Cat turning the objective eccentric ring to collimate a freshly cleaned glass.

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#43 Ant1

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Posted 29 March 2019 - 02:28 PM

Hi

 

I intended no disrespect wrinting my post #19 above and fully agree with the author of the books referred to multiple times that building and using a collimator is all about image position, a lot more than quality.

My point is to say that spherical aberration is going to cause parallel light rays entering the device to hit the collimator target at different locations.

A quick sketch (eggagerated) will explain what I have in mind :

Capture.jpg

 

This phenomenon introduces some error in the collimation procedure.

The parallel rays exiting the auxiliary telescope are spaced very near each other so the associated error can be neglected.

The error associated with the binocular's objective spacing (or swinging distance) will be much more important.

The issue will get worse with shorter collimator f-ratios and higher binocular magnification.

Most 50mm aperture binoculars will have a typical objective spacing of 5 inches, and a collimator with approx 50 inches focal length (as I suspect the MkV is) will effectively operate at roughly f/10 and yield very nice results.

I became aware of this issue trying to implement a setup with a f/2.5 lens scavenged from a reading magnifier and gathering a lot of frustration.

 

Just wanted to save others the trouble of figuring it out.

Again no disrespect intended.

 

Regards,

Ant1



#44 NDfarmer

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Posted 29 March 2019 - 05:19 PM

Daughter Cat turning the objective eccentric ring to collimate a freshly cleaned glass.

Thanks much for posting the photos of Suddarth Optical in action.  I knew that Cory's son was in the operation, and

I'm also pleased to see his daughter.  I like that.



#45 SMark

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Posted 29 March 2019 - 05:21 PM

Thanks much for posting the photos of Suddarth Optical in action.  I knew that Cory's son was in the operation, and

I'm also pleased to see his daughter.  I like that.

Definitely a family business.



#46 NDfarmer

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Posted 29 March 2019 - 05:33 PM

Hi

 

I intended no disrespect wrinting my post #19 above and fully agree with the author of the books referred to multiple times that building and using a collimator is all about image position, a lot more than quality.

My point is to say that spherical aberration is going to cause parallel light rays entering the device to hit the collimator target at different locations.

A quick sketch (eggagerated) will explain what I have in mind :

Capture.jpg

 

This phenomenon introduces some error in the collimation procedure.

The parallel rays exiting the auxiliary telescope are spaced very near each other so the associated error can be neglected.

The error associated with the binocular's objective spacing (or swinging distance) will be much more important.

The issue will get worse with shorter collimator f-ratios and higher binocular magnification.

Most 50mm aperture binoculars will have a typical objective spacing of 5 inches, and a collimator with approx 50 inches focal length (as I suspect the MkV is) will effectively operate at roughly f/10 and yield very nice results.

I became aware of this issue trying to implement a setup with a f/2.5 lens scavenged from a reading magnifier and gathering a lot of frustration.

 

Just wanted to save others the trouble of figuring it out.

Again no disrespect intended.

 

Regards,

Ant1

 

Ant: 

I am no expert in collimation, but I think it is important to know every binocular has different kinds and

levels of aberration. 

 

I think what matters is the collimation process involves centering each lens and joining the image. 

 

There would be no real method of trying to do what you are showing.  Just think how difficult this would be, each telescope or barrel may have different aberrations.

 

The collimation process involves the doing the best you can, with what you have. This will make the view satisfactory and help the binocular do the best it can. 

 

That is how I see it, I hope others will chime in.



#47 SandyHouTex

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Posted 30 March 2019 - 08:27 AM

Hi

 

I intended no disrespect wrinting my post #19 above and fully agree with the author of the books referred to multiple times that building and using a collimator is all about image position, a lot more than quality.

My point is to say that spherical aberration is going to cause parallel light rays entering the device to hit the collimator target at different locations.

A quick sketch (eggagerated) will explain what I have in mind :

Capture.jpg

 

This phenomenon introduces some error in the collimation procedure.

The parallel rays exiting the auxiliary telescope are spaced very near each other so the associated error can be neglected.

The error associated with the binocular's objective spacing (or swinging distance) will be much more important.

The issue will get worse with shorter collimator f-ratios and higher binocular magnification.

Most 50mm aperture binoculars will have a typical objective spacing of 5 inches, and a collimator with approx 50 inches focal length (as I suspect the MkV is) will effectively operate at roughly f/10 and yield very nice results.

I became aware of this issue trying to implement a setup with a f/2.5 lens scavenged from a reading magnifier and gathering a lot of frustration.

 

Just wanted to save others the trouble of figuring it out.

Again no disrespect intended.

 

Regards,

Ant1

I still think a green filter would fix this.



#48 Mad Matt

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Posted 30 March 2019 - 12:57 PM

Hi

I intended no disrespect wrinting my post #19 above and fully agree with the author of the books referred to multiple times that building and using a collimator is all about image position, a lot more than quality.
My point is to say that spherical aberration is going to cause parallel light rays entering the device to hit the collimator target at different locations.
A quick sketch (eggagerated) will explain what I have in mind :
Capture.jpg

This phenomenon introduces some error in the collimation procedure.
The parallel rays exiting the auxiliary telescope are spaced very near each other so the associated error can be neglected.
The error associated with the binocular's objective spacing (or swinging distance) will be much more important.
The issue will get worse with shorter collimator f-ratios and higher binocular magnification.
Most 50mm aperture binoculars will have a typical objective spacing of 5 inches, and a collimator with approx 50 inches focal length (as I suspect the MkV is) will effectively operate at roughly f/10 and yield very nice results.
I became aware of this issue trying to implement a setup with a f/2.5 lens scavenged from a reading magnifier and gathering a lot of frustration.

Just wanted to save others the trouble of figuring it out.
Again no disrespect intended.

Regards,
Ant1


This is where using a fresnel lens becomes interesting. They can be made to correct SA similar to using an aspheric surface on the lenses you have in your drawing. I believe fresnel lenses that correct for SA are called imaging lenses.
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#49 SMark

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Posted 30 March 2019 - 03:37 PM

This should add some clarity to the above...

Attached Files


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#50 SMark

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Posted 30 March 2019 - 06:36 PM

And more pics and description from Cory...

 

 

Collimator components. 10 inch optics. The twin PCX lenses are of plain common window glass. No matter though, this is set up with a monochromatic light source, chromatic is a non issue. This DuraCell bulb illuminates the green filter material, AND illuminates the annoying ghost images associated with a green filter and a CFL or incandescent or fluorescent bulb. Use the bulb, poof, ghosting gone. Clean green light.

 

The non-reticle flat glass (under the green bulb) just needs to get frosted as it will be the light diffuser.

 

With a lighter frame (aluminum), taking a collimator out to the Okie-Tex Star Party will be much easier!

Attached Thumbnails

  • IMG_3012.JPG
  • IMG_3013.JPG
  • IMG_3014.jpeg

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