Thermal monoculars - anybody using them? (4 Viewers)

[androidvireo]

Hi all,
I am about to bite the bullet and order a thermal monocular (Pulsar Helion 2 XP50) to help detect woodcock, grouse, owls, etc. and hopefully reduce flushing or other disturbance. There is a very informative thread from 2017-2019 discussing member Vollmeise's experience with a first gen version of the same model of scope I am looking at, as well as this blog from 2016 or so detailing Suan Hsi Yong's experience with thermal imaging devices... I am curious if anyone else has any more recent experience with using thermal imagers in their birding?

 

[opisska]

Check out this thread for experience of many people, including myself Night vision equipment for mortals

I have a 35mm Helion. Finding ground birds in grassland is not easy, you can miss a Jack Snipe 5 meters from you, but we have also found a migrating Woodcock in a field. We are looking mostly for mammals though, the best birding benefits of IR were in Costa Rica where it really helped in the shady and dark rainforests, producing an Antpitta and Tinamou as well as several rare birds found sleeping on branches in the night.

 

[jurek]

It is generally very useful. If you can afford it, buy it.

However it has limitations. Most obviously, birds often hide behind vegetation, which thermal scope cannot penetrate. But neither can your eyesight. You can check also this thread, and similar on mammalwatching:

How do you use your thermal imager to find wildlife? – Mammal Watching

www.mammalwatching.com

I recommend looking around for the lowest price, because there are differences of several 100EUR. If you need more advice, PM me.

 

[wllmspd]

I’ve found owls and hedgehog with an Axion XM30S. You want low mag for scanning areas and high mag for getting detail, so ideally two systems. A cold sky can muck up the contrast scaling making finding warm to ings kn trees quite tricky sometimes. I switch between the different contrast options (rock/tree/custom etc) to help make things more visible.
Very handy tool. Animals get quite annoyed when they realise you can see them rather well!

Peter

 

[androidvireo]

Check out this thread for experience of many people, including myself Night vision equipment for mortals

I have a 35mm Helion. Finding ground birds in grassland is not easy, you can miss a Jack Snipe 5 meters from you, but we have also found a migrating Woodcock in a field. We are looking mostly for mammals though, the best birding benefits of IR were in Costa Rica where it really helped in the shady and dark rainforests, producing an Antpitta and Tinamou as well as several rare birds found sleeping on branches in the night.

Thank you for your reply.

I also looked at that thread when I was doing my initial research - it was very interesting and informative.

Grassland birds are one of my main interests as I have 15 acres of pasture, and I have a couple pairs of Bobolinks, Eastern Meadowlarks, Vesper Sparrows and several pairs of Savannah Sparrows nesting in there annually. I also recently heard Northern Bobwhite calling but have not gotten eyes on it yet - they are considered endangered in Ontario so I would like to keep tabs on it. I'm aware the handheld thermal monocular would not be ideal for surveying these birds, but it would be helpful. I have a few elevated places I can stand to get some height for a bit more advantage, and I think in conjunction with a spotting scope like what Vollmeise set up it might work. Ideally, I'd be using a thermal camera attached to a drone like these folks in North Dakota. If you go to 1:50 they find a Vesper Sparrow nest with their system - very cool.

What's the minimum focusing distance of the 35mm Helion? This is my big concern with the 50mm... although the extra reach will be handy in lots of situations, I often find myself in close conifer plantations or wooded areas and I imagine a min focusing distance of 7m to be too much.

That's part of my reasoning for getting the Helion 2 XP50 rather than the Helion 2 XP50 PRO - it has the interchangeable lens system which has now been discontinued. If I got a 28mm lens (min focusing distance around 1m) along with it I would be set. Can't find one anywhere, though. My current plan is to get the XP50 and hope that a 28mm will pop up on the secondary market. I was planning on posting a Wanted ad in the classifeds here once I had made myself a bit more well known in the forums.

 

[androidvireo]

It is generally very useful. If you can afford it, buy it.

However it has limitations. Most obviously, birds often hide behind vegetation, which thermal scope cannot penetrate. But neither can your eyesight. You can check also this thread, and similar on mammalwatching:

How do you use your thermal imager to find wildlife? – Mammal Watching

www.mammalwatching.com

I recommend looking around for the lowest price, because there are differences of several 100EUR. If you need more advice, PM me.

Thanks Jurek. What model did you end up with?

 

[androidvireo]

I’ve found owls and hedgehog with an Axion XM30S. You want low mag for scanning areas and high mag for getting detail, so ideally two systems. A cold sky can muck up the contrast scaling making finding warm to ings kn trees quite tricky sometimes. I switch between the different contrast options (rock/tree/custom etc) to help make things more visible.
Very handy tool. Animals get quite annoyed when they realise you can see them rather well!

Peter

Thanks Peter. Do you find the resolution on the XM30s to be sufficient for locating anything smaller than owls and hedgehogs or is it limited to animals of that size? And what is the minimum focusing distance?

 

[jurek]

My experiences are with Pulsar Helion 2 XP50.

Note: choosing a thermal viewer, choose as wide field of view as possible, and secondarily the number of pixel in the matrix. The first determines ease of finding wildlife. The second determines how far away you can see animals: basically, as far as the animal will fill one pixel making it a warm dot on a cold background. Lower resolution means lower maximum distance.

Pulsar Helion 2 XP50 allows seeing mice or sparrows at several 10s of m, and roe deer for several 100s of m or more. Basically, as far as this animal would be visible on a white snow as a black dot.

One uses the lowest magnification to cover maximum field of view. Don't worry about minimum focus. Unfocused image will do fine. It is not possible to identify a thermal image to species other than by shape and movement. Colors don't show on IR. All small birds look uniform hot or hot with darker (colder) wings and tails. For identifying species of e.g. songbirds, you need to switch to binoculars.

In your case, you will have success in short-grass areas and in the open country. It is much faster to see small birds on the ground or in a bare bush using thermal. They show as bright dots on dark background, without the confusing factor of the motley vegetation. If you have a flock of pipits, with your bins you see 1, 2 or 3 and with a thermal all flock members. Camouflaged larger birds in the open one can see easily from a big distance, e.g. snipes on a mud or a woodcock on bare forest floor. It is difficult to see birds in tall grass, dense bushes or forest foliage. They often perch completely behind foliage (they purposefully choose such places), the IR is blocked and you don't see them, unless you move and switch the angle.

 

[wllmspd]

As thermal has comparatively low resolution, detailed ID is not possible. Field of view is an important consideration… high magnification is useful, but then it’s like looking at the world through a narrow tube. I nearly fell over a Badger once as I’d been unaware it was nearby…. Though I could follow it through the bushes as it trundled off.
You’ll be frustrated by warm boobs in bushes and trees and no way to work out exactly where they are to point normal optics at (the thermal view isn’t always easy to correlate to the binocular view).

For finding warm creatures in the dark it is invaluable! Without it I’d still never have seen any owls in a local park.

Peter

 

[opisska]

A really useful think to do is to mount a laser pointer to you IR, so you can point where the animal is. Without it, finding birds in a bush is next to impossible. There is no commercial solution for this, you just have to buy a pointer and rig some mounting, best done using the tripod mount on the Pulsars.

 

[Andrew Whitehouse]

Can anyone comment on the usefulness of thermal binoculars, as opposed to monoculars? Like others, I've found that one of the problems of using thermal binoculars is assessing the distance to the object. Does a binocular thermal image improve depth perception and the sense of distance, thus making it easier to find the thing you can see in regular binoculars?

 

[jurek]

As far I know, thermal binoculars are one viewer split into two eyepieces = not giving perception of the depth. Having double view would mean two matrices and would raise the cost to astronomical prices. So maybe in future, if the technology becomes cheaper.

I never had much problem with judging distance, maybe because I tend to move a little, a step forward or to the side, and see how the scenery changes.

 

[wllmspd]

The clever thing to do would be to use a sensitive camera based “digital night vision” system and a long wavength (900nm) flood illuminator and a similarly invisible laser pointer, this way the critters won’t be put off by people pointing dazzling lights in their faces (well you are, but they’ll be unaware of it). To help coaling a pointer to a thermal a 3D printer may come in handy.
As said, thermal binocukars are just 2 screens with the same picture and are likely to stay that way for a good while.

Peter

 

[Hauksen]

Hi Jan,

A really useful think to do is to mount a laser pointer to you IR, so you can point where the animal is. Without it, finding birds in a bush is next to impossible. There is no commercial solution for this, you just have to buy a pointer and rig some mounting, best done using the tripod mount on the Pulsars.

I'd think a reflex sight might do the trick even better, avoiding the disturbance a laser pointer might create.

Looking at the pictures of the Pulsar XM30S, it seems the tripod screw is in the front, and with the right-hander grip-strap installed, the sight could conveniently sit to the left of the scope?

Might be fairly simple for me to come up with a 3D printable adapter, in case you're interested.

Regards,

Henning

 

[Hauksen]

Hi Peter,

As said, thermal binocukars are just 2 screens with the same picture and are likely to stay that way for a good while.

I think some of the cheaper thermal imagers used around the house to check electrics, heating systems, etc. already have a mode in which they overlay the thermal image with a visual image. Not sure about the way they accomplish it, but adding a low resolution visual light camera to a thermal scope probably wouldn't require any great feats of engineering. Never mind the parallax, low resolution and fairly long viewing distance (in our use case) make it a minor concern.

Regards,

Henning

 

[wllmspd]

Thermal works best at big when things cool off and the wildlife is easier to spot. The visible camera on your thermal system will show nothing in that case. The field of view of these handheld indoor units is so broad that anything that far away will look like a dot.

Peter

 

[androidvireo]

As thermal has comparatively low resolution, detailed ID is not possible. Field of view is an important consideration… high magnification is useful, but then it’s like looking at the world through a narrow tube. I nearly fell over a Badger once as I’d been unaware it was nearby…. Though I could follow it through the bushes as it trundled off.
You’ll be frustrated by warm boobs in bushes and trees and no way to work out exactly where they are to point normal optics at (the thermal view isn’t always easy to correlate to the binocular view).

For finding warm creatures in the dark it is invaluable! Without it I’d still never have seen any owls in a local park.

Peter

I have no illusions about trying to ID birds to species using thermal. I'm just hoping to enhance my detection of birds and get a general idea of what category they fall into (am I looking at a sparrow or a grouse? etc.), then relocate the bird with regular optics.

It sounds like I really should be looking at a 28mm lens for maximum field of view. I think the only Pulsar product available right now with 28mm is the Lexion XP28, which is a professional thermal monocular - basically the same specs as the Helion 2 XP50 though.

Lexion has a FOV of 22x16.6 degrees / 39x29 m at 100m, compared to the Helion 2 XP50 12.4x9.3 degrees / 21.8x16.3 m at 100m. Almost 2x the FOV.

I was under the impression the general public could not purchase the Lexion series, but I emailed Brandon Optics here in Canada and they say it's only the rifle-mounted scopes that are restricted sale.

 

[opisska]

Hi Jan,



I'd think a reflex sight might do the trick even better, avoiding the disturbance a laser pointer might create.

Looking at the pictures of the Pulsar XM30S, it seems the tripod screw is in the front, and with the right-hander grip-strap installed, the sight could conveniently sit to the left of the scope?

Might be fairly simple for me to come up with a 3D printable adapter, in case you're interested.

Regards,

Henning

Yeah that could actually work well for a lone user. We have chosen the laser method because it shows the position to the other person (who then tries to get a photo with a camera) but for a single person, the sight sounds better because of the lack of disturbance!

 

[Hauksen]

Hi Peter,

Thermal works best at big when things cool off and the wildlife is easier to spot. The visible camera on your thermal system will show nothing in that case. The field of view of these handheld indoor units is so broad that anything that far away will look like a dot.

You're probably right. I wasn't suggesting using a direct copy, but the low resolution visual sensor can be matched to the thermal sensor with a small fixed-length lens, which still can be quite compact and cheap Of course, the darker it gets, the more important image intensification becomes, which in turn relies on the presence of at least some amount of ambient light - unless you opt for near-IR and use a suitable illuminator. The point is, generating a composite image from using different ranges of the spectrum could make it easier for the human eye to interpret the picture and make a connection to the real-world situation.

I believe in military and security use, there are already some sensors going that route - at least, that's my impression from some slightly off-topic search results Google provided.

Regards,

Henning

 

[Hauksen]

Hi Jan,

Yeah that could actually work well for a lone user. We have chosen the laser method because it shows the position to the other person (who then tries to get a photo with a camera) but for a single person, the sight sounds better because of the lack of disturbance!

Ah, I see. Of course, if photography is the intention, it would also be possible to design a mount that connects thermal scope and camera so that they are pointing at the same spot, for the solo user.

Something not unlike like this might work, though I imagine you're not using that big a tele lens at night ...

NATO/Picatinny Rail for Lens Collar by Bikecyclist

NATO/Picatinny Rail for Lens CollarAdds a NATO rail mount to your lens collar so you can mount a red dot sight to your tele lens.Fits accurately over the 38 mm wide tripod mount of the "Bigma" Sigma 50-500 mm (Sony mount). Snug fit ensures that the sight mounts with repeatable accuracy every...

www.thingiverse.com

Regards,

Henning