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The importance of glass in night vision monoculars

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37 replies to this topic

#26 maxmir

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Posted 28 June 2021 - 08:34 PM

Well I didn't get an answer, I started sorting out on my own.
You can't make M31 there. Only M27, M26, etc.

In addition, a stop ring must be made on the lens so that the lens does not fall inside the NV.

 

Maxmir, you would post a photo. Who will make it later will be unclear.

For Mod3, you need to solve the issue with the setting to infinity. There is no adjustment on the lens. It is necessary to make an adapter with a greater thickness and cut it off little by little with a milling cutter, followed by a star check.
As a result, experimentally find the required thickness.
Let me remind you that for afocal use it is desirable that the lens be focused to infinity.

To use 1x for me is not relevant. Zeiss Tevidon works well for me. Although options are possible ...

Here is what I made.

Note : I turned down the first 1-2 mm too much.

It exposed some plastic substrate. The lens is still quite solid.

 

It comes to focus as shown; right where the threads end.

Attached Thumbnails

  • Lens1.jpg
  • Lens2.jpg

Edited by maxmir, 28 June 2021 - 08:42 PM.


#27 maxmir

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Posted 28 June 2021 - 08:41 PM

This shows the home made afocal adapter that mates to Russell eyepieces.

I gripped the adapter in the lathe chuck so as not to crush the lens.

 

Attached Thumbnails

  • Lens3.jpg


#28 maxmir

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Posted 28 June 2021 - 08:50 PM

I though about removing the o ring to the right and machining a collar as stop.

 

I found that it has not been necessary so far.

I did not find a problem with lens rotating with my afocal set up.

I got the threads fitting just about right.



#29 a__l

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Posted 28 June 2021 - 09:04 PM

I don't see the name my the Lens either. I know the Kosher surplus l told me he only builds PVS-14 with Carson components.

Your lens has the inscription "1XEP3" this is Carson



#30 a__l

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Posted 28 June 2021 - 09:16 PM

I will make an adapter M31-> M26.5 (most likely), I do not like plastic substrate.
In addition a stop ring will be made. Or I will not cut part of the thread (blue arrow) if the length of the thread allows, or I will make a more complex adapter with a stop on the existing ring (red arrow).

Attached Thumbnails

  • Carson_.jpg


#31 maxmir

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Posted 28 June 2021 - 09:27 PM

I was hoping to make a stop on the C threads.
Unfortunately the threads are flush at infinty on the Mod3c

If you turn down to 0.993 , I don't think you will hit plastic

#32 a__l

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Posted 28 June 2021 - 09:27 PM

This shows the home made afocal adapter that mates to Russell eyepieces.

I gripped the adapter in the lathe chuck so as not to crush the lens.

I have TV 55/67.
I removed the conical adapter from this eyepiece and made an adapter to the Zeiss Tevidon filter thread on one side and screwed it onto the TV plossl thread on the other.
The Zeiss lens requires the closest position to the eyepiece lens. From here it works with a little vignetting with the TV55 and decently more with the TV67. I do not like this.
What distance to make between the TV67 eyepiece and the PVS-14 lens, I don't know yet. An experiment is needed.
The principle of the adapter will be the same as with the Zeiss.



#33 a__l

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Posted 01 July 2021 - 07:01 PM

Do not try to cut lathe with PVS-14 lenses from other manufacturers. They will be divided into two parts with a diameter of 26.5 mm.

Probably maxmir luck with the device body.


Edited by a__l, 01 July 2021 - 07:04 PM.


#34 maxmir

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Posted 02 July 2021 - 08:07 AM

Do not try to cut lathe with PVS-14 lenses from other manufacturers. They will be divided into two parts with a diameter of 26.5 mm.

Probably maxmir luck with the device body.

Did you try turning one or was this a observation ?

 

Max



#35 a__l

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Posted 02 July 2021 - 12:50 PM

Yes, my one fell apart on a lathe.
I had to spend a lot of time and make two aluminum rings. Internal and external. And glue the two parts together. The work is not completed yet, the result is unknown.

Attached Thumbnails

  • Lens_1.jpeg

Edited by a__l, 02 July 2021 - 01:01 PM.

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#36 Fivemileshigh

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Posted 16 July 2021 - 11:08 AM

Yes, OVNI-B are made from MIL-SPEC PVS-7 parts.

But not with the 1st prototypes I made like the one you own.

There are few other differences between prototypes and final version available since end of 2020.

Just curious Joko, does the OVNI-M use the Carson objective lens?

 

Thanks!



#37 Joko

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Posted 16 July 2021 - 01:58 PM

Just curious Joko, does the OVNI-M use the Carson objective lens?

 

Thanks!

Nope it doesn't.

Carson objectives lens are specific to the PVS-14, same design but better than PVS-14 ENVIS lens (from what i can read, i never tried the Carson lens). About NV lenses, it seems nobody agree which lens is the best, some people don't like the PVS-14 ENVIS lens (or similar), some people like it a lot, some people prefers camera lens, some prefers OVNI lens...there are many point of view.

The advantage of the OVNI-M is you can change the lens easily so you can try other lenses.


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#38 a__l

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Posted 16 July 2021 - 06:01 PM

 About NV lenses, it seems nobody agree which lens is the best, some people don't like the PVS-14 ENVIS lens (or similar), some people like it a lot, some people prefers camera lens, some prefers OVNI lens...there are many point of view.

 

For astronomy, I see only one application for such a lens. This is an afocal use.
It's easy enough to rate everyone. Take a photo of stars in the same conditions with different lenses.
Gavster writes about "I received the Carson body kit this week and transferred my fom 2600 tube to it. The results are amazing. Stars are now pinpoint across the field of view, better than my actinblack and in indoor testing the additional sharpness and resolution of the views is very apparent. Clearly it was the commercial glass that was the issue not the tube !! "
Therefore, we are still expecting a comparative photo.




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