69 replies to this topic

[Gavster]

I’m a big advocate of afocal night vision astronomy. However, I’ve enjoyed having the option of using my pvs14 in prime as per this thread (I can get all my scopes to work in prime mode with this adapter including dobs and refractors)

 

https://www.cloudyni...ith-parts-list/

 

However, very shortly after this was posted, the trybe adapter was discontinued meaning that pvs14 became problematical to convert to prime again (if you didn’t already have the trybe). There were also a few aspects of the trybe adapter which I wasn’t that keen on - the clip on approach meant that there was a possibility that the adapter wasn’t square to the image intensifier and the clip on adapter did let in some light to the side which isn’t ideal if you have some light pollution.

 

With the help of someone on CN, I was able to provide rafcamera with a bespoke design for a screw in adapter to convert a pvs14 to prime. You need to unscrew the infinity stop on the pvs14 (which may also have some set screws that need removing with an Allen key), then the adapter screws onto the thread that is revealed. Be careful when screwing on as the threads are quite fine.

I kept the adapter short so that the front lens can be easily screwed in and out and removed as required. For prime use you need to add a 10mm t2 extension to fully clear the battery cap which I also got rafcamera to design. It needed to be as slim as possible to enable the adapter to clear the battery cap on the Carson pvs14 body. On the elbit body there is more space to the battery cap so also fine with that body. 

As this adapter is screw on it eliminates the issues of the trybe adapter as well.
 

links to the adapter and extension tube below

https://rafcamera.co...m42x0-75f?amp=1
https://rafcamera.co...-t2m-10mm?amp=1

pics with it attached to Carson and elbit pvs14s shown below 

Attached Thumbnails

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[Joko]

Very nice !

Adapting PVS-14 to prime is not new so i think it's important to explain the previous steps :

https://www.cloudyni...per-14-chassis/

https://www.cloudyni...ith-parts-list/

 

To do the same method you need to remove the intensifier tube and the retention ring with specific tools, which is not an easy task.

With the non significant effect of voiding the warranty.

 

It's great that you achieved focus in all your telescopes because most people who experimented on Cloudynights don't achieve focus with their PVS-14 in prime due to the big distance between the flange and the photocathode (around 45mm in your case). Meaning the focuser needs at least 45mm backfocus but often it will requires much more.

Edited by Joko, 05 April 2023 - 05:27 AM.

[Gavster]

Very nice !

Adapting PVS-14 to prime is not new so i think it's important to explain the previous steps :

https://www.cloudyni...per-14-chassis/

https://www.cloudyni...ith-parts-list/

 

To do the same method you need to remove the intensifier tube and the retention ring with specific tools, which is not an easy task.

With the non significant effect of voiding the warranty.

 

It's great that you achieved focus in all your telescopes because most people who experimented on Cloudynights don't achieve focus with their PVS-14 in prime due to the big distance between the flange and the photocathode (around 45mm in your case). Meaning the focuser needs at least 45mm backfocus but often it will requires much more.

Some pvs14 dealers will supply the pvs14 new with the retention ring already removed and will give a 2 year warranty. Removing it isn’t difficult since it takes me only about 5 mins
I only know of four people that currently use a pvs14 in prime mode and to my knowledge none of them have had any issues achieving focus with their telescopes (being able to screw the t2 thread directly onto a diagonal helps with this)

Edited by Gavster, 05 April 2023 - 05:57 AM.

[cnoct]

The significance of this contribution is impossible to overstate, well done Gavster . 
 
IDK Joko but I think you'd do well to embrace the 14 in all realized configurations. The demand for the 14 isn't waining. as far as compatibility, well that's up to the end user to determine. The 'flange' to focal plane is known so as with so many other calculations/considerations, I'd imagine the end user could assess this before choosing the appropriate system. I'd really like to see this on offer from you .

[jconroy]

Nice work Gavster!

 

I always wanted to try Prime Focus NVD photography but without the Trybe part I was stuck. Thanks for taking the initiative and coordinating it with Rafcamera. You may want to let him know to produce more parts because I would imagine the orders are going to start flowing in immediately. I'm really looking forward to how this prime focus photography will add a new dimension to my night vision astronomy. 

Edited by jconroy, 05 April 2023 - 06:38 AM.

[Joko]

Nice work Gavster!

 

I always wanted to try Prime Focus NVD photography but without the Trybe part I was stuck. Thanks for taking the initiative and coordinating it with Rafcamera. You may want to let him know to produce more parts because I would imagine the orders are going to start flowing in immediately. I'm really looking forward to how this prime focus photography will add a new dimension to my night vision astronomy. 

IMO prime is a must have. Most people who have a choice between afocal and prime will choose prime. There was a thread I opened last year and most people preferred prime, some liked both equally and only one member preferred afocal :

https://www.cloudyni...your-favourite/

 

Look forward to read your prime review with PVS-14. You're going to like prime method ! 

[bbasiaga]

I could not find a dealer willing to warranty my PVS14 without the ring.  Even ones reported here as issuing a warranty to others.  I guess I didn't ask the correct question the correct way.  

 

Also none of my dobs had enough in-focus to reach the sensor on a PVS14 anyway.  So not a real loss for me.  I may pick this adapter up anyway for the future - when the warranty is over I could always have the ring removed.  It should still work on my 80mm refractor and SCT. 

 

-Brian

[Gavster]

I could not find a dealer willing to warranty my PVS14 without the ring.  Even ones reported here as issuing a warranty to others.  I guess I didn't ask the correct question the correct way.  

 

Also none of my dobs had enough in-focus to reach the sensor on a PVS14 anyway.  So not a real loss for me.  I may pick this adapter up anyway for the future - when the warranty is over I could always have the ring removed.  It should still work on my 80mm refractor and SCT. 

 

-Brian

I’ve been told in the past week that at least one well known good nv dealer will. I’ll pm you. If you directly screw the pvs14 into the coma corrector rather than use a nosepiece that should help you get to focus with it.

[Gavster]

The adapter is sold out already! But rafcamera will have more stock in 3-4 weeks

[Highburymark]

Very interesting - thanks Gavin. I haven’t explored prime with my PVS but I’ll order one of the next batch.

[Gavster]

Very interesting - thanks Gavin. I haven’t explored prime with my PVS but I’ll order one of the next batch.

Mark, I’d be happy to assist you with the installation if you would like.

[a__l]

Probably it is necessary to decide what distance we are talking about. The difference between the focusing of eyepieces and some correctors for astrophotography can be 50 mm or more (inside). For example, my 0.95x SharpStar and P2 differ by this distance. P2 is made compatible with eyepieces (Nagler 31, Ethos 21 - max inside -0.38").

However, all of this is used by ATMs.

Edited by a__l, 07 April 2023 - 06:35 AM.

[sixela]

Not all scopes have the focal plane at least 55mm above the tacked in focuser (which is typical for astrophotography scopes).

I’m using lots of coma correctors but apart from the Paracorr I need to recess them into the focuser on some scopes.

Edited by sixela, 07 April 2023 - 09:53 AM.

[a__l]

https://www.cloudyni...sis/?p=10233548

About 48 mm.

https://www.televue....id=61&Tab=_phot

For P2 56 mm.

https://agenaastro.c...-4-trg1072.html

If you make such an adapter with a longer M42x0.75 thread/tube, then most likely you will not have problems using it on a standard visual newton with P2.

The M42 thread must be made so that the PVS-14 knob does not rest against the adapter body and had the opportunity to turn.

As an option, make another RAF adapter for PVS-14 with an extended body for M42 and use the TV adapter without changes.

Edited by a__l, 07 April 2023 - 06:54 PM.

[vineyard]

Cheers Gav, that sounds very interesting.  Just ordered the last unit that was available in Raf's restock!  I'll msg you once it arrives for installation tips pls?  I guess it can also then be put as prime focus behind a prime DSLR lens (if the backfocus for the lens can be met) for handheld as well as on a scope.  Cheers!

[Dewbeard]

Looks like there's a new adapter now:

https://rafcamera.co...r-t2f-to-pvs-14

 

Is there any good reason to prefer this new one over the ones linked by Gavster at the top of the thread?

[cnoct]

I get along lovely with the latch option from Sector Optics , same as was once branded TRYBE latch from Optics Planet.

 

However, if my choice was between the RAF adapter designed by Gavster or the one designed by rfr66, I'd choose Gavster's adapter design. 

Ignoring all else, my choice is strictly based on the unrestricted aperture afforded by Gavster's design, the full I.D. of the PVS-14 upper is available without restriction. 

 

As for the mechanics and longevity, I think that favors the adapter design by rfr66. The threads on the glass filled plastic (ultimo) 14 uppers probably won't take to as much stress and use such as multiple cycles of mounting and un-mounting of said adapter. No real reason to be doing so but that could be a potential for failure, the threads are rather fine and some uppers have a seam on either side that may reduce integrity of the threads. That is all a non-issue if one has an aluminum upper from say Knights Armament: https://www.knightar...ssories-kv/m-14

 

Mechanics seem to favor the adapter designed by rfr66 and believe it to be a more rigid and structurally sound design. The interior diameter of that aperture is awful narrow for such a relatively long in air distance to the input window. That diameter to length has me  .

I'd suggest buying both and see which works for ones own preferences, the cost is trivial for such innovation and what the option affords. 

 

My compliments to both rfr66 and Gavster.

[davidgmd]

Very cool Gavster. I’m a budding NV enthusiast.  The Tele Vue version just arrived but I haven’t even unboxed it yet. I’ll get some experience with it in afocal mode before attempting any modifications but your adapter looks like a simple answer to a tough problem.

  
For visual use, would it work to substitute a Baader T2 nosepiece (#2458130) for the 10 mm T2 extension tube and slide it into a 2” diagonal? Or is that a goofy idea that would only occur to someone with no practical experience (me)? Link to the nosepiece: https://www.baader-p...ftey-kerfs.html

[sixela]

The 10mm T2 extension is there to clear the battery cap. But of course after that you can go to a 2" rather than 1.25" nosepiece. I actually use both in prime focus, simply because I have both 1.25" and 2" barlows.

Edited by sixela, 13 July 2023 - 08:01 AM.

[Dewbeard]

I’m a big advocate of afocal night vision astronomy. However, I’ve enjoyed having the option of using my pvs14 in prime as per this thread (I can get all my scopes to work in prime mode with this adapter including dobs and refractors)

 

https://www.cloudyni...ith-parts-list/

 

However, very shortly after this was posted, the trybe adapter was discontinued meaning that pvs14 became problematical to convert to prime again (if you didn’t already have the trybe). There were also a few aspects of the trybe adapter which I wasn’t that keen on - the clip on approach meant that there was a possibility that the adapter wasn’t square to the image intensifier and the clip on adapter did let in some light to the side which isn’t ideal if you have some light pollution.

 

With the help of someone on CN, I was able to provide rafcamera with a bespoke design for a screw in adapter to convert a pvs14 to prime. You need to unscrew the infinity stop on the pvs14 (which may also have some set screws that need removing with an Allen key), then the adapter screws onto the thread that is revealed. Be careful when screwing on as the threads are quite fine.

I kept the adapter short so that the front lens can be easily screwed in and out and removed as required. For prime use you need to add a 10mm t2 extension to fully clear the battery cap which I also got rafcamera to design. It needed to be as slim as possible to enable the adapter to clear the battery cap on the Carson pvs14 body. On the elbit body there is more space to the battery cap so also fine with that body. 

As this adapter is screw on it eliminates the issues of the trybe adapter as well.
 

links to the adapter and extension tube below

https://rafcamera.co...m42x0-75f?amp=1
https://rafcamera.co...-t2m-10mm?amp=1

pics with it attached to Carson and elbit pvs14s shown below 

Two unfortunate differences with what I got:

• No knurling on the adapter making it harder to screw in.
• The M33.2x0.8 is too wide or my battery cap is too wide, but either way it doesn't fit. The battery cap scrapes the anodization or paint off of the adapter.

Not too happy about this, because it cost in total 73 euros including shipping. I'll probably have to sand away thickness off of the adapter to make it work, and find some way to make it screw on in a smoother fashion.

Edited by Dewbeard, 21 July 2023 - 08:30 AM.

[sixela]

Have you contacted Raf about this?

[Dewbeard]

Talked back and forth with Raf. I might have gotten an early batch of the adapter left over in Austria. The width of the M33.2x0.8 to M42 adapter was correct, and according to Raf it's basically already at minimum thickness, so nothing to be done. As for the M33.2x0.8 threads themselves ... it should screw on smoothly/easily to the male thread of the PVS-14, but the thread is too tight and the friction becomes too much after a few mm. Secure and usable, but not as intended, and the lack of knurling makes it a little bit harder to turn.

 

Plan A was printing a spacer between the battery compartment and the tube housing, plan B sanding/filing off aluminum from the adapter. Plan A worked after making the thickness 0.7mm (otherwise the power supply contacts from battery compartment don't touch the tube, no current, no image). Overall I'm happy with the mod. Removing the rings was not too hard with the dedicated PVS-14 tools, the objective without the two removed rings feels just as secure as before.

 

I'm not too happy about the 10mm M42 spacer together with the adapter. I could have bought it way cheaper, and with my PVS-14/adapter combo it's basically useless (I screw an M42->M48 ring directly on the adapter because I can't screw the adapter on fully). All other RAF camera adapters I bought so far did their jobs very well, this one ... not out of the box. 

 

There's a new RAF camera adapter that basically behaves like an objective. Bigger (and as a result costs more and probably weighs more), might still have the same M42 ring width problem, but at least you bypass the M33.2x0.8 thread. Maybe worth considering for people wanting to run their 14 prime.

Edited by Dewbeard, 28 July 2023 - 12:37 PM.

[Gavster]

Talked back and forth with Raf. I might have gotten an early batch of the adapter left over in Austria. The width of the M33.2x0.8 to M42 adapter was correct, and according to Raf it's basically already at minimum thickness, so nothing to be done. As for the M33.2x0.8 threads themselves ... it should screw on smoothly/easily to the male thread of the PVS-14, but the thread is too tight and the friction becomes too much after a few mm. Secure and usable, but not as intended, and the lack of knurling makes it a little bit harder to turn.

 

Plan A was printing a spacer between the battery compartment and the tube housing, plan B sanding/filing off aluminum from the adapter. Plan A worked after making the thickness 0.7mm (otherwise the power supply contacts from battery compartment don't touch the tube, no current, no image). Overall I'm happy with the mod. Removing the rings was not too hard with the dedicated PVS-14 tools, the objective without the two removed rings feels just as secure as before.

 

I'm not too happy about the 10mm M42 spacer together with the adapter. I could have bought it way cheaper, and with my PVS-14/adapter combo it's basically useless (I screw an M42->M48 ring directly on the adapter because I can't screw the adapter on fully). All other RAF camera adapters I bought so far did their jobs very well, this one ... not out of the box. 

 

There's a new RAF camera adapter that basically behaves like an objective. Bigger (and as a result costs more and probably weighs more), might still have the same M42 ring width problem, but at least you bypass the M33.2x0.8 thread. Maybe worth considering for people wanting to run their 14 prime.

Which Pvs-14 body are you using? Carson, Elbit or Optronics Engineering? 

[davidgmd]

I have a TNVC PVS14 from Tele Vue. The battery compartment holds 1 AA. Is that a Carson body?

 

Can anyone here help me with step-by-step directions for removing the objective lens to reveal the M33.2x0.8 threads?

[Dewbeard]

Which Pvs-14 body are you using? Carson, Elbit or Optronics Engineering? 

Carson, that's what the seller said it was and that's what it resembles in pictures online.