Matching IR illuminator to NV scope

[mealiejimmy]

Using an aftermarket IR illuminator with an NV scope is pretty common these days but choosing the right IR illuminator to work well with any given scope is not straightforward because none of the aftermarket IR suppliers state the minimum and maximum beam angle of their products
Ideally, the beam from the IR illuminator should fill the field of view of the scope with enough IR to produce a usable image of the entire field of view
If the beam is too narrow then, at maximum beam angle there will be dark areas away from the centre of the field of view and at minimum beam angle a strong probability of the scope sensor being overloaded and the image "whiting out"
Russ Douglas and I have managed to get our hands on a few of the commonly available aftermarket IR illuminators and measure their minimum and maximum beam angles
I've listed them below and then, for comparison, the field of view (at base magnification for some common NV scopes

IR illuminator minimum and maximum beam angles

Model	Minimum beam angle (deg)	Maximum beam angle (deg)
Solaris SRX V2	1.48	3.66
Sirius XTL (diffused)	2.60	5.77
HIK Alpex LED	3.20	5.26
Blacksun dark engine	2.18	4.20
V20/Night blaster	1.22	Not measurable
DS35-50 RF	2.83	5.75
Light Sabre Wraith	1.67	3.29
Wraith lite 88 pill	2.00	6.18
Wraith lite Original 7060 vcsel	2.13	6.02

For comparison here are the horizontal fields of view (in degrees) of several common NV scopes

Pulsar C50 - 6.7
HIK Alpex - 6.2
HIK Cheetah - 8.1
PARD DS35-50 - 4.4
PARD DS35-70 - 2.86
PARD 008S - 3.61
IRay TD50L - 6.6



A couple of examples to illustrate what we're trying to show here:
The Solaris SRX has a maximum beam angle of 3.66 degrees
That means it would fill the field of view of the PARD DS35-70 and the PARD 008S and would be an excellent choice for those scopes (if it was felt that the onboard IR illuminators were insufficient)
However, it would not anywhere near fill the field of view of the C50, Alpex, Cheetah or IRay
I've actually tested the Solaris SRX V2 with the Alpex and with the beam at it's maximum angle, the field of view is less than half filled.
Conversely, the same scope when used with the Sirius XTL (5.77 degrees maximum) had it's field of view almost completely filled with a very nice even level of illumination.
Please note - I'm not knocking any particular illuminator, I'm just trying to make it easier for people who want to buy an aftermarket illuminator to buy something that will work well with their particular NV scope

Cheers

Bruce

 

[Fair Hill]

I can only applaud your mission to help others by constantly sharing your expertise in the field of night vision, (Russ too by the way).

 

[Jelen]

That's a good post, thanks.

 

[BLUEROLL]

Thanks for that info Bruce and Russ.
Is the Sirius XTL the only one that is diffused and are there any black holes visible in the beam of any when on flood please ?

 

[mealiejimmy]

Of those listed, I believe the Sirius XTL (now known as the Sirius Reach) is the only one with a diffuser
There was no noticeable black hole on any of the torches listed, although I felt the Sirius produced the smoothest and most even illumination over the widest area
I do have some other pills that I did not list mainly because they do exhibit black holes

Cheers

Bruce

 

[jthyttin]

Ludicrous Lumens Wraith has diffuser option and I got one 850nm pill to use with Gen3 as rear addon. Haven't tested it properly since I happened to get thermal scope at the same time and was playing with it, and we don't have proper dark nights here in Finland at spring/summer time. But the beam was beautiful, filled the FOV of 3-18x50 Meopta Optika6. My only concern is how the beam behaves at narrow end, will it e.g. suffice for 500m ID of static quarry. Wraith dimmer is top notch, no problem getting the power low enough for Gen3.

 

[Boosh]

Good info!
Personally I would not allow the tightest of beams to be the deal breaker in choice though.
At longer distances the tight beam of a modern laser in reality has a usable FOV with capability of giving a clear image.
(Personally a LL Wraith 850nm x2 lens behind a Sightmark Wraith HD can show a clear image at 500mtrs with the beam tightened down with more than enough FOV, maybe half the screen filled).
This image ****es all over my 10x Drone (sorry guys).
The nicest image I have seen through my set up was with a Sirius XTL diffused. OK nowhere near as much reach, but so much cleaner up to 300+ mtrs.

 

[BLUEROLL]

Of those listed, I believe the Sirius XTL (now known as the Sirius Reach) is the only one with a diffuser
There was no noticeable black hole on any of the torches listed, although I felt the Sirius produced the smoothest and most even illumination over the widest area
I do have some other pills that I did not list mainly because they do exhibit black holes

Cheers

Bruce

Thanks Bruce.

 

[Clive Ward]

Great work Bruce!

We've got something new coming out very soon. I'll send one up to you and Russ to have a play with and add to the table.


Cheers





Clive

 

[mealiejimmy]

Clive,
Excellent!! - we look forward to that.
The manufacturer of the Solaris SRX V2 is telling us that his product has been changed to produce a wider beam and is also sending us a sample to test.

Cheers

Bruce

 

[Cyres]

Bruce
Excellent piece of work. Any chance of some data on suitability of external IR with different NV scopes eg N470s and basic Photon. I use both and the Photon despite its age is still v good for ratting and bunny bashing but does need suitable external IR. Also not everybody can afford some of these top end IR systems so some data on for example Night Fox torches would be good.
D

 

[mealiejimmy]

The field of view for the scopes you listed are as follows:
Yukon Sightline N470S - 4.1 degrees
Yukon Photon 4.5x42 - 4.3 degrees
Yukon Photon 6x50 - 3.3 degrees
Just look at the table with the beam angles of the various illuminators and find one or more that fills the field of view of those Yukon scopes
If Night Fox send us a torch or torches, we'll test it/them

Cheers

Bruce

 

[Jono 4]

I'm realy new to the night vision IR situation, one of my farmers now have a lot of free range chickens so I have started to shoot a few foxes and can see this increasing as the winter comes, so I have a Infiray TD50l scope and would like a better add on IR, and would appreciate the ones to look at. Many thanks

 

[Hunter 6.5]

Great post, I am new to night visions but highly appreciate your efforts. Thanks

 

[Overlay]

Well done Bruce and Russ for putting in all the time and effort to keep everyone up to date and avoid some of the pitfalls with mix and matching Nv scopes and IR”s

really appreciated Guys

 

[mealiejimmy]

I'm realy new to the night vision IR situation, one of my farmers now have a lot of free range chickens so I have started to shoot a few foxes and can see this increasing as the winter comes, so I have a Infiray TD50l scope and would like a better add on IR, and would appreciate the ones to look at. Many thanks

Look at the table above.
Your TD50L has a field of view of 6.6 degrees, so to fill it's field of view with IR, you'll need an IR illuminator that, with it's beam set to flood will have a beam angle of around 6.6 degrees
Of the IR illuminators tested and easily available, the Sirius XTL (now called the Sirius Reach) would be the best fit.

Cheers

Bruce

 

[Jono 4]

Thanks Bruce thats great