Thermal hunting

[TassieTiger]

I posted a while back that after a fair bit of home work, I bought a cheapie "Night Tech" Thermal imager. It was always gonna be a toe in the water for me, so far I've been quite impressed. I have been reading more about them since and this is a run down on what I've picked up.
There are quite a few specs that need to be taken into consideration before buying a thermal spotter, without knowing the basics you could easily drop a large amount of dosh on something that's gonna disappoint. These are some of the ones I know about.

Imager Resolution: This the amount of thermal capturing "units", called microbolometers that are contained within the imager sensor. The lowest resolution that's seems to be acceptable is the 320x240. The next up from this is 384x288 ( what my unit has ) and after that is the 640x480. The higher the resolution the better the captured image detail.

Refresh rate: This is the amount of times a second the viewer will display a new image. A higher refresh rate gives a smoother view of the heat sources movements. Really you don't wanna go below 25 HZ as the human eye can then detect the break in images. There are some cheap units that run a 9Hz refresh rate which would give an extremely chunky view of what's happening.

Lens Size: This is the physical size of the germanium lens with in the unit. The larger the lens the further the imager can detect a heat source, there is, however a trade off. The larger the lens the smaller the field of view, also costlier. Generally for spotters, the larger field of view is preferred while on a scope the opposite is true.

Display Resolution and type: This is the details on the actual display that can be seen with the eye. It is referred to in pixel quantities. For example the Pulsar XM38 has a 1024x768 AMOLED display. This is considered to be quite high. Once again the higher the resolution the better the detail of the heat source that is captured by the imager.

Pixel Size: The size of the pixels contained within the sensor. Smaller the better. 17um seems to be the accepted with 12um being a step up on some of the Pulsar Axions.

Detection distance: This figure will be given and it needs to be taken with a grain of salt. How it is determined is by the distance the given object will be detected by one imager pixel. So that figure of say 900m for a man size object would probably be halved to give a useful sort of image. There is the ID distance and the detection distance. The detection distance is the distance that you will see something where the ID is where the object can be ID'd.

These figures all contribute to the quality of the viewer. They need to be considered in conjuction with one another. There are certain models that have a lower image sensor resolution yet compensate for it by higher display resolution and smaller pixel size. If you take a look at the monocular that's shown on this page:

https://www.nighthunter.com.au/thermal- ... hd-25-lite

This is the model I went for. It's a common body shape that's used in a lot of different viewers that are manufactured under different brand names eg, Night Tech, Pearl, Guide, Stag, IMax and Iray being a few of them. If you want to go for a known and respected brand eg Pulsar, you wont get the same level of specs for a particular price point than if you go for one of the, can I say " knock off ", brands that I just listed.
On the other hand there are some cheap units that come from respected brands that offer extremely low level specs ( to the point of almost being useless). The Leupold Tracker is probably the best example. If you want get into thermal at entry price point then I feel you're much better going for one of the "knock off" brands.
If you don't mind spending big then by all means go for the premium brands. I know my next purchase will be a Pulsar ( XQ38f ) a way down the track though.

After all this, I'll say that my budget handheld thermal is awesome, it makes hunting so much more enjoyable and I use probably 3 times a week.

Nice write up - I’m not in the market not want for a thermal at this point in time, but I’ve learned a lot from your post. Cheers.

[brinny]

Hey all....Been a while since i have been on...
Has been some pretty interesting developments with the thermal gear i have been using....I "HAD" Pulsar XQ50 thermals and have had a shocking run with them....
They have given me all sorts of grief with loss of POI....In most cases shifting 3 inches off target....and that has been the case with all three that i have had....so enough was enough and sent them all on their merry way back to the distributor....
What i have now is an interesting scope....
I have purchased a GSCI TI S675 thermal..Canadian made.....has the 640 core, against the XQ50s 384....I have only just taken delivery of it last Thursday and fitted it to the rifle over the weekend....
I took it down to my range yesterday afternoon and sighted it in, and was plesently suprised with the ease of operation, and accuracy of this scope....
I cant tell to much at this point as i havent tried it out in the field, however early indications are very good at what i think it will perform like....
I set the initial target up at 25m, and let the farting around with what button does what, where and how tos....got on the paper and in the bull....then shifted to 50m and repeated the process.....
Finally set a new target up at 100m with the first shot going high as expected.....second shot a tad low but in the bull none the less....slight adjustment and placed the third shot where i wanted it.....then proceeded in putting a further ten shots in the group highlighted with the blue line....not too shabby for a new scope....
The scope wasnt cheap by any means, at $10,500 i would expect it to perform at 100 percent....
The test will be out in the field....and just hope like hell this one holds zero....

[brinny]

I do mostly walking with my thermal gear but when I’m temporarily mobile because of bigger distances I have to cover I greatly favour my quad rather than my hilux. ( the cold tortures me in winter but at least I don’t have a windscreen in the way. ... I tried a thermal bino on top of my dog cage that sits at the back of my quad .. it sent a wifi signal to my iPad that I had mounted up front so I could see it at all times ... but I found that as I was driving slow and quiet with not even my red head lights on, it was easier to simply hold the binos in my left hand and scan like that, stopping for a better and more stable look when required. Then when game is identified I know I can rely on the silent approach on foot. I would dismount with binos and rifle and walk into the wind towards my target/s I am so incredibly lucky that this 8-10 sq kilometres of farming land is s o incredibly flat with not a single ditch or watercourse to run into. If it were not for the occasional tree or pile of logs I could drive it in the dark safely blindfolded. The flatness also suits my bipod / prone shooting position .. there’s never even a slight mound of earth in the way .....I just need to win lotto so I can hunt there for a week every month

I have set up a Polaris RZR as a dedicated night hunting rig....It has a Blaza light on a swivel, as well as a Pulsar Helion XQ50 monocular that wifis down to a Samsung Android tablet that is setup behind the steering wheel....i have fitted USB ports to plug the leads in to keep them running all night....seems to work ok ...

[Stix]

Hey-ya Brinny...

Nice to hear you've got that Pulsar stuff sorted...

Im as envious of your set-up & opportunities as i am keen to see some results...

Nice stock on the rig--plain, but nice...many Sako's have plain & boring bit of walnut, but for a plain one, that does look good...
(I still havent fired mine...not one shot... ).

I have to say & ask...it looks 'ding' free...how do you achieve that with a night time rig...?...I realise using thermal you'd often avoid the situation of having to rush in getting the rifle out the window, but still id expect the odd knock here & there, & that looks as if its never been bruised...

[brinny]

Hey-ya Brinny...

Nice to hear you've got that Pulsar stuff sorted...

Im as envious of your set-up & opportunities as i am keen to see some results...

Nice stock on the rig--plain, but nice...many Sako's have plain & boring bit of walnut, but for a plain one, that does look good...
(I still havent fired mine...not one shot... ).

I have to say & ask...it looks 'ding' free...how do you achieve that with a night time rig...?...I realise using thermal you'd often avoid the situation of having to rush in getting the rifle out the window, but still id expect the odd knock here & there, & that looks as if its never been bruised...

Hi mate....
Yeah....I had a really s**t run with Pulsar scopes....had 4 and they all failed....the original Apex XD75 failed when the shutter stuck when calibrating and wouldnt release....sent it back and i was sent an Xq50 Trail as a replacement.
It went ok for a while and i bought another one.
The replacement scope started to loose POI and had shutter sticking issues as well so it was sent back and a new one sent as a replacment.
It wouldnt hold zero either so it was sent back and i started using the second one i had purchased.
It also wouldnt hold zero so it has gone back.
It is a very wide spread problem as a lot of others worldwide are having the same issue and its not just confined to the XQ50s....I know blokes with the XP50s that are having the same issue.
The XQs i had would shoot out some 3 inches at 100m....I shoot a lot of foxes out at 2-250m, and at that distance it would be out 6 plus inches, and thats a miss every time....not good enough for the money we pay for these things.

The XQ50 Helion monocular i have, the shutter will stick when calibrating on that too and i have to keep turning it off and on to get it to release....
So no more Pulsar scopes for me......
Looking forward to seeing how the GSCI goes.....

The Sako is a bit more bruised than it looks......closer inspection reveales a "LOT" of marks on it....
Those plain walnut stocks are pretty average eh...
Your not going to fire that first shot out of yours sitting on the couch watching Days of our lives mate...
Got to get out there and into them....

[niteowl]

:allegedly:

I posted a while back that after a fair bit of home work, I bought a cheapie "Night Tech" Thermal imager. It was always gonna be a toe in the water for me, so far I've been quite impressed. I have been reading more about them since and this is a run down on what I've picked up.
There are quite a few specs that need to be taken into consideration before buying a thermal spotter, without knowing the basics you could easily drop a large amount of dosh on something that's gonna disappoint. These are some of the ones I know about.

Imager Resolution: This the amount of thermal capturing "units", called microbolometers that are contained within the imager sensor. The lowest resolution that's seems to be acceptable is the 320x240. The next up from this is 384x288 ( what my unit has ) and after that is the 640x480. The higher the resolution the better the captured image detail.

Refresh rate: This is the amount of times a second the viewer will display a new image. A higher refresh rate gives a smoother view of the heat sources movements. Really you don't wanna go below 25 HZ as the human eye can then detect the break in images. There are some cheap units that run a 9Hz refresh rate which would give an extremely chunky view of what's happening.

Lens Size: This is the physical size of the germanium lens with in the unit. The larger the lens the further the imager can detect a heat source, there is, however a trade off. The larger the lens the smaller the field of view, also costlier. Generally for spotters, the larger field of view is preferred while on a scope the opposite is true.

Display Resolution and type: This is the details on the actual display that can be seen with the eye. It is referred to in pixel quantities. For example the Pulsar XM38 has a 1024x768 AMOLED display. This is considered to be quite high. Once again the higher the resolution the better the detail of the heat source that is captured by the imager.

Pixel Size: The size of the pixels contained within the sensor. Smaller the better. 17um seems to be the accepted with 12um being a step up on some of the Pulsar Axions.

Detection distance: This figure will be given and it needs to be taken with a grain of salt. How it is determined is by the distance the given object will be detected by one imager pixel. So that figure of say 900m for a man size object would probably be halved to give a useful sort of image. There is the ID distance and the detection distance. The detection distance is the distance that you will see something where the ID is where the object can be ID'd.

These figures all contribute to the quality of the viewer. They need to be considered in conjuction with one another. There are certain models that have a lower image sensor resolution yet compensate for it by higher display resolution and smaller pixel size. If you take a look at the monocular that's shown on this page:

https://www.nighthunter.com.au/thermal- ... hd-25-lite

This is the model I went for. It's a common body shape that's used in a lot of different viewers that are manufactured under different brand names eg, Night Tech, Pearl, Guide, Stag, IMax and Iray being a few of them. If you want to go for a known and respected brand eg Pulsar, you wont get the same level of specs for a particular price point than if you go for one of the, can I say " knock off ", brands that I just listed.
On the other hand there are some cheap units that come from respected brands that offer extremely low level specs ( to the point of almost being useless). The Leupold Tracker is probably the best example. If you want get into thermal at entry price point then I feel you're much better going for one of the "knock off" brands.
If you don't mind spending big then by all means go for the premium brands. I know my next purchase will be a Pulsar ( XQ38f ) a way down the track though.

After all this, I'll say that my budget handheld thermal is awesome, it makes hunting so much more enjoyable and I use probably 3 times a week.

Nice write up - I’m not in the market not want for a thermal at this point in time, but I’ve learned a lot from your post. Cheers.

I do not wish to criticize anyone for their write up but couple of points need clarifying, this is always hard to do with text but here goes -

Lens size, which size do you refer to? Lens diameter governs the lens "speed" which in turn governs the system sensitivity, but don't be too alarmed, it only means the difference of a few 1000s of a degree. Lens length, focal length, will determine the optical magnification with any given FPA size and therefore the field of view and range.

Pixel size is quite correct, don't be misled, going to a smaller pixel size but having the same number, the image when interpolated to the viewing OLED will be "stretched" more and will not look any different to a slightly larger pixel size FPA.

Detection distance is complex and is based on the "Johnson Criteria" which, for a start is a calculated figure ONLY and provides two figures based on a 50% and a 90% chance of a result of detecting a human size target at the stated distance. This has no bearing on prevailing conditions which will alter the figures HUGELY. Manufacturers generally give a figure between the extremes as a guide. Recognition and Identification are again shorter distances. Most better manufacturers provide these as "DRI".
?????? Really? This is not quite what it seems.

It appears there are some things that are not readily understood about "night vision". There are three main types of gear that are referred to - Digital, works day or night, can have really good resolution but needs a heap of IR to be any use at night, does NOT "magnify" light. Image intensifying, will "magnify" light by varying degrees, depending on Generation from 1000 to 70000 times. Used only at night (unless we go into autogating and that is limited to just before dark and just after daylight), can be enhanced with the use of IR, but it is not an IR device. Thermal is an IR device as it detects only a band of IR but NO visible light. Flir gained its name as - forward looking infrared. Can be used day or night.
Using IR has problems among other things, IR CAN be seen by nocturnal animals as well as the VERY visible red light from the illuminator. Covert wave lengths 920 / 940 nm are better with the visible red light but the animals can see this IR too. They do get wary after a time like they do with a spotlight.