What is best practice for spotting animals with a thermal scope?

Spotlighting – shining a bright light (usually while moving in a vehicle) is the dominant way to find nocturnal mammals.   However many of us have bought thermal vision monoculars or viewers which allow finding a mammal at night with no additional light.   I have a Pulsar Helion, but so far it has been less useful to me than I would have expected.    Yet a set of scientific papers has concluded that in many (but not all) cases it is superior to spotlighting for doing animal surveys

Here are two recent examples

https://researchonline.jcu.edu.au/74704/ ,


Yet my experience has been that it is not easy to use thermal imaging as an alternative to spotlighting.   Partly that might be due to having the wrong color palette on my imager (Pulsar helion).   The display seems very bright, so it is tiring to look through it for long periods of time.  The brightness can be turned down of course, but then it is harder to spot.  Its occurred to me that I am probably the weak link in the chain – I’m probably not doing it right.

One possible way to deal with eye fatique is to not use the eyepiece but instead use a setup with a small flat panel monitor.  This is often done with video cameras, and always done with drones.  I have yet to try this for thermal scopes, and there may be issues I am not thinking of.

Amazon lists this book, which is out in a few days https://www.amazon.com/Thermal-Imaging-Wildlife-Applications-PGC002/dp/178427416X/ref=sr_1_3?crid=2Q7DZSUBJI8WM&keywords=thermal+imaging+wildlife+book&qid=1696201030&sprefix=thermal+imaging+wildlife+book%2Caps%2C136&sr=8-3  I have it on order, and possibly that will give me some clues.

I am wondering if somebody on the mammal watching list has some tips about best practices for spotting animals with a thermal scope.   It would seem like a great thing to share on the site, but that said, as noted above I don’t think I have figured it out.  Hopefully some of you have.


Post author

Nathan Myhrvold


  • Zarek Cockar

    Hi Nathan,
    I have some of the same struggles as you, but I’ve gotten used to my thermal (Lahoux Spotter T) and now I don’t know how I ever lived without it. While spotlighting generally relies on picking up the eyeshine of a mammal, thermal scoping will pick up an animal whose face may be obscured by vegetation, or which is facing away from you. Similarly, thermals WON’T pick up wolf spiders and nightjars, which often cause confusion with a spotlight.
    My suggestions:
    – Use the ‘white hot’ setting, and increase the contrast
    – Decrease the brightness all the way. Mine is on the lowest setting and I have no problem distinguishing a mammal from the surrounding vegetation
    – Accept that there will be some loss of darkness vision in the scoping eye. I try to stick with one eye so my other eye maintains better vision in the dark when I need it (especially when walking).
    – Keep your torch/flashlight in your other hand, so you can quickly spotlight whatever you see in the thermal. Have your thermal on a strap attached to your hand or wrist, so you can drop it and pick up your binoculars and flashlight at the same time.
    – Do night walks with a companion. One of you can be designated thermal-scoper, while the other just uses a flashlight. Be careful, however, to ensure whomever is using the spotlight doesn’t scare animals away. I find red lights work best.
    – Practice switching your concentration from the thermal eye to the non-thermal eye so you can peer out into the dark or use your torch to see where you’re going. The more you do this, the more you can use your thermal on the move without having to stop too much.
    – As someone else who uses thermals often to try yours out and see if they find anything strange or uncomfortable about it.
    At the end of the day, you just have to use it often, and in different situations to get used to it and figure out what works best for you. It may also be that you never get fully accustomed to it, and prefer not to use it. And that’s ok, too.

  • Jonatan den Haan

    Hi Nathan,

    Your struggles are very valid, it takes some getting used to and tinkering with the settings to find your optimal way. As Zarek already said, turn up the contrast and set the brightness on the lowest setting. Try to go out with a friend or your pet and and try adjusting the settings to your liking. What you want is a low brightness screen where every mammal jumps out as a super white bright dot. There are also options in the menu if you want to “identify” or if you want to “observe” (it’s called differently but I can’t remember the right term). You don’t want to identify them, you want to see any mammal that enters the scope. You will identify them later with your flashlight.
    You will loose a clear sight of your surroundings in your scope, but that doesn’t really matter as your main goal is to find mammals, not walk in the dark.

    Go out, fck around and find out! 🙂
    You will find your way!

    Happy mammal watching!

  • jurekmammalwatching

    I kept my scope to the eye at the beginning. Now I watch through the thermal scope maybe 10% of the time or less. I normally stop, scan the area, move a little, scan again. I watch the layout of the land, so when you move I scan again e.g. only inside that little depression in the ground which became visible, and that grove of trees from another angle.

    Perhaps most useful is: beforehand pick a route where you can move easily, and avoid tall dense vegetation (bush, crops, reeds) where mammals are invisible.


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