Night Vision Clip on Thermal - what's needed from the daylight scope?

[MeatAxe556]

Admittedly, I'm a noob at thermal optics, but want to get into one. Clip ons seem to be the most versatile. However, I assume you have to focus your daytime scope on the video screen of the thermal, just millimeters away. This seems impossible with my daylight scopes, except possibly 1x red dots.

What do I need in a daytime scope in order to focus / utilize the thermal clip on? It almost seems that I'd need a macro setting on a rifle scope to get an extreme close up on the thermal screen.

Thanks!

 

[wigwamitus]

The thermal clipon include optics on the rear end that among other things, include a focusing lens. So, the thermal clipon will take care of the problem for you.

 

[bikeracer]

Wig - you are the SME here. Ive been reading your posts for a couple of years culminating in my purchase of a demo LWTS. If you have the time I’d love to better understand the details behind the question and your answer. I have just set up my LWTS as a dedicated unit - will move on to clip on status next with a NF ATACR 1-8.

 

[wigwamitus]

Last summer, setup a test platform to test design for rear end optics for a thermal clipon.

On the left side is a cheapy athon scope with a camera on the user end. Next, in the middle is a sightmark 7x magnifier reversed to act as a demagnifier ... then next in the chain is the focusing lens module which at this time was three stacked 3x jewelers magnifying (focusing) lenses. After that is a 0.5 inch 1024x768 display connected to the PC to display images.

The purpose of all this was to test what it took to get a decent image from 6x up to 24x, the magnification range of the day scope and to get some hands on experience working with this problem set.

==

Here we are zoomed out to 7x ... 6x was a little fuzzy. Later we changed out the triple 3x stack and replaced with a single 10x focusing lens and 6x was much better.

==

Here was are at 12x ...

==

And here was are at 24x ...

==
Unexpectedly, it turned out the hard part was 6x ... but again, that was solved by improving the focusing lens.

==
In a real thermal clipon (and real thermal clipons are very rare) there is also an "optical wedge" (aka risley prism) set which provides collimation for the clipon, provided the rear end optical train is collimated on a collimating table.

Such collimation provides a tolerance within which the clipon and day scope can be mis-aligned without affecting POI. Some clipons (be they NV or thermal) have higher tolerance (like PVS-30) others have lower tolerance like PVS-24. But in simple terms, only the high end thermal clipons, the military ones have collimating lenses. AFAIK, none of the commercial ones do, even though some of them say they do. That said I think ALL the commercial ones have bore sight adjustments, which enable you to compensate for the lack of collimation by adjustments. But which that adjustment need to be checked up on remount ? When you first get one, you should check it at least 2 dozen times, night after night removing and reattaching to get familiar with the process and get consistent and shoot groups and see where you are. Then you can decide, for your setup, whether you need to check zero each time you mount. There are several variables, including YOU.

 

[MeatAxe556]

Last summer, setup a test platform to test design for rear end optics for a thermal clipon.

Last summer, setup a test platform to test design for rear end optics for a thermal clipon.

On the left side is a cheapy athon scope with a camera on the user end. Next, in the middle is a sightmark 7x magnifier reversed to act as a demagnifier ... then next in the chain is the focusing lens module which at this time was three stacked 3x jewelers magnifying (focusing) lenses. After that is a 0.5 inch 1024x768 display connected to the PC to display images.

The purpose of all this was to test what it took to get a decent image from 6x up to 24x, the magnification range of the day scope and to get some hands on experience working with this problem set.

==

Here we are zoomed out to 7x ... 6x was a little fuzzy. Later we changed out the triple 3x stack and replaced with a single 10x focusing lens and 6x was much better.

==

Here was are at 12x ...

==

And here was are at 24x ...

==
Unexpectedly, it turned out the hard part was 6x ... but again, that was solved by improving the focusing lens.

==
In a real thermal clipon (and real thermal clipons are very rare) there is also an "optical wedge" (aka risley prism) set which provides collimation for the clipon, provided the rear end optical train is collimated on a collimating table.

Such collimation provides a tolerance within which the clipon and day scope can be mis-aligned without affecting POI. Some clipons (be they NV or thermal) have higher tolerance (like PVS-30) others have lower tolerance like PVS-24. But in simple terms, only the high end thermal clipons, the military ones have collimating lenses. AFAIK, none of the commercial ones do, even though some of them say they do. That said I think ALL the commercial ones have bore sight adjustments, which enable you to compensate for the lack of collimation by adjustments. But which that adjustment need to be checked up on remount ? When you first get one, you should check it at least 2 dozen times, night after night removing and reattaching to get familiar with the process and get consistent and shoot groups and see where you are. Then you can decide, for your setup, whether you need to check zero each time you mount. There are several variables, including YOU.

On the left side is a cheapy athon scope with a camera on the user end. Next, in the middle is a sightmark 7x magnifier reversed to act as a demagnifier ... then next in the chain is the focusing lens module which at this time was three stacked 3x jewelers magnifying (focusing) lenses. After that is a 0.5 inch 1024x768 display connected to the PC to display images.

The purpose of all this was to test what it took to get a decent image from 6x up to 24x, the magnification range of the day scope and to get some hands on experience working with this problem set.

==

Here we are zoomed out to 7x ... 6x was a little fuzzy. Later we changed out the triple 3x stack and replaced with a single 10x focusing lens and 6x was much better.

==

Here was are at 12x ...

==

And here was are at 24x ...

==
Unexpectedly, it turned out the hard part was 6x ... but again, that was solved by improving the focusing lens.

==
In a real thermal clipon (and real thermal clipons are very rare) there is also an "optical wedge" (aka risley prism) set which provides collimation for the clipon, provided the rear end optical train is collimated on a collimating table.

Such collimation provides a tolerance within which the clipon and day scope can be mis-aligned without affecting POI. Some clipons (be they NV or thermal) have higher tolerance (like PVS-30) others have lower tolerance like PVS-24. But in simple terms, only the high end thermal clipons, the military ones have collimating lenses. AFAIK, none of the commercial ones do, even though some of them say they do. That said I think ALL the commercial ones have bore sight adjustments, which enable you to compensate for the lack of collimation by adjustments. But which that adjustment need to be checked up on remount ? When you first get one, you should check it at least 2 dozen times, night after night removing and reattaching to get familiar with the process and get consistent and shoot groups and see where you are. Then you can decide, for your setup, whether you need to check zero each time you mount. There are several variables, including YOU.

Last summer, setup a test platform to test design for rear end optics for a thermal clipon.

On the left side is a cheapy athon scope with a camera on the user end. Next, in the middle is a sightmark 7x magnifier reversed to act as a demagnifier ... then next in the chain is the focusing lens module which at this time was three stacked 3x jewelers magnifying (focusing) lenses. After that is a 0.5 inch 1024x768 display connected to the PC to display images.

The purpose of all this was to test what it took to get a decent image from 6x up to 24x, the magnification range of the day scope and to get some hands on experience working with this problem set.

==

Here we are zoomed out to 7x ... 6x was a little fuzzy. Later we changed out the triple 3x stack and replaced with a single 10x focusing lens and 6x was much better.

==

Here was are at 12x ...

==

And here was are at 24x ...

==
Unexpectedly, it turned out the hard part was 6x ... but again, that was solved by improving the focusing lens.

==
In a real thermal clipon (and real thermal clipons are very rare) there is also an "optical wedge" (aka risley prism) set which provides collimation for the clipon, provided the rear end optical train is collimated on a collimating table.

Such collimation provides a tolerance within which the clipon and day scope can be mis-aligned without affecting POI. Some clipons (be they NV or thermal) have higher tolerance (like PVS-30) others have lower tolerance like PVS-24. But in simple terms, only the high end thermal clipons, the military ones have collimating lenses. AFAIK, none of the commercial ones do, even though some of them say they do. That said I think ALL the commercial ones have bore sight adjustments, which enable you to compensate for the lack of collimation by adjustments. But which that adjustment need to be checked up on remount ? When you first get one, you should check it at least 2 dozen times, night after night removing and reattaching to get familiar with the process and get consistent and shoot groups and see where you are. Then you can decide, for your setup, whether you need to check zero each time you mount. There are several variables, including YOU.

Thanks for all that info! Much to consider!

So it seems that a "Clip On" doesn't simply "clip on" to work with a daylight scope. There's a lot that goes into interfacing the two optics.

 

[bikeracer]

Thanks for this Wig - I’m still taking it all in but I’m assuming the LWTS is considered a true collaborated clip on?

 

[wigwamitus]

... There's a lot that goes into interfacing the two optics ..

Exactly ... and the "magic" is on the rear end !!!

==

... I’m assuming the LWTS is considered a true collaborated clip on ...

I haven't had an LWTS so I cannot say based on testing. But I have had an LWTS-LR and can say that it is collimated yes.

 

[MeatAxe556]

 

[Markhammett]

I am currently going back and forth with L3 trying to correct a pretty substantial shift with my LWTS. Tech asked me in an email if i have bore sighted it. I know some clip ons you can adjust the screen for impact shifts, but if you can with a lWTS I can’t figure it out. Image is pretty good on anything 6x or less though.