Thermal Optics for Wildlife Viewing

[Garfield]

FWIW I've been thinking about a thermal optic device for a couple years so after perusing this thread I picked up the Topdon and have been playing around with it in bird mode. There are plenty of limitations as anyone who reads this thread well knows, but I think it's a pretty neat little device that will come in handy so I'm definitely keeping it. More resolution would be nice but not essential to me; I mainly want it for short range use (spotting bird nests) so if it reveals a hot spot it won't take me long to zero it on it with my regular binos. I wish it had a wider field of view but the Topdon is serviceable. My impression is that I'd have to spend several times the cost to get a significantly better device, which probably wouldn't be worth it for me. I'm sure we'll see continued improvements with these devices as time goes by.

Edit: I be remiss not to thank @nmerc_photos for doing all the work to create this thread.

 

[arbitrage]

Well I ended up returning the Topdon but I'm still conflicted if that was the best choice. I was torn all day yesterday as to what to do. I was literally walking down trails with one scope up against either eye, alternating closing one eye or the other...ridiculous...glad I didn't trip and fall...LOL.

I still think the Topdon in Bird mode is the best at really bringing an actual bird in the scene to your attention because it is almost a black screen and only the brightest things light up. But you don't have a clue what bush, tree, distance the bird actually is at. The AGM is so much better to stroll around and look through. It of course sees everything the Topdon does but sometimes you have to take a bit more time to notice what is actually the brightest spot when there are other competing bright spots.

 

[nmerc_photos]

I'd be interested for some of you 256 and 384 guys to try a 640 sometime and see if it's worth the upgrade. I can't wait for a year or two from now when they're more affordable and everyone can have them.

To me, 640 is where things really get interesting.

I haven't been out using my wildlife thermal lately, but it should be time for my GHO pair to nest up and have babies if they haven't already. So maybe I'll get out this weekend.

In the meantime, semi-related - I bought a $300 Topdon TC002C to help with general house stuff. I bought an old farmhouse on a river, built in 1948. It had no door sweeps or weatherstripping around the front door. A lil thermal action made quick work of that.

 

[splatbass]

My question is about temperatures. I live in Hawaii where daytime temperatures are usually in the upper 80s in summer and upper 70s to lower 80s in the winter, with early morning temps sometimes in the 60s in the winter. Do they work well in hot weather, where the temperature differential between the air and the animal is smaller? It seems like they would be better in cold weather, and all of the YT videos I’ve seen were filmed in cold weather.

 

[nmerc_photos]

My question is about temperatures. I live in Hawaii where daytime temperatures are usually in the upper 80s in summer and upper 70s to lower 80s in the winter, with early morning temps sometimes in the 60s in the winter. Do they work well in hot weather, where the temperature differential between the air and the animal is smaller? It seems like they would be better in cold weather, and all of the YT videos I’ve seen were filmed in cold weather.

The greater the thermal difference, the better the outcome.

But we still use them in Hawaii, Costa Rica, Africa, etc. When I was on the Big Island a few years ago (or maybe last year?) our bird guide was using a thermal. It's all about knowing how and when to get the best outcome from your gear.

If you're in dark canopied areas, they tend to work really well regardless of temperature - because there isn't as much sunlight penetrating through.

 

[splatbass]

The greater the thermal difference, the better the outcome.

But we still use them in Hawaii, Costa Rica, Africa, etc. When I was on the Big Island a few years ago (or maybe last year?) our bird guide was using a thermal. It's all about knowing how and when to get the best outcome from your gear.

If you're in dark canopied areas, they tend to work really well regardless of temperature - because there isn't as much sunlight penetrating through.

Great, thank you. Oftentimes I hear a bird in a tree but can't see it, so I think it would be useful. A little while ago I was walking in the park and heard some of the friendly neighborhood Ring Necked Parakeets (introduced). I coudn't find them until three of them took off. And they are FAST when flying, so seeing them before they take off is key.

 

[ABaumgardner]

Hit or miss with the Topdon so far. I haven't located a single bird I already did not know was there yet. And this includes use from about 45 minutes before sunrise, temps in the low 40s. In part I don't think many birds were around, but I did see a small warbler sized bird about 15 yards away but it was almost invisible in the Topdon. I definitely would not have located it using the Topdon. Probably too small of a bird to register any heat signature, especially with the resolution of the Topdon. I have observed the bird mode in action while at home with pigeons about 59 yards away, overcast in the 50s just a little after sunrise. So it has potential, probably more so for larger birds and mammals. Unfortunately I think any smaller mammals and most birds will be "lost in the noise" beyond 50-75 yards or so. I wish I had more time to test it. I'm currently unsure if I will keep it. I might return it, and purchase a much higher resolution and more sensitive unit in the fall.

 

[AlanB313]

I've decided that in my case, investing in a thermal isn't the immediate need. My fastest lens is my 300mm f4 pf and I think I could really use a 70-200mm F2.8 in my use case. I like to try for common poorwill. Night owls might be beyond my current skill sets.

Poorwill are an interesting bird. They use torpor, and can lower their body temp as low as to 5 C, and reduce their oxygen consumption by 90%. Their instinct is to freeze in place when threatened and look like a rock, which they are good at.

A couple of times I've had good luck. They take a long careful approach. Keeping your light on them is important. I don't use flash. As soon as the light leaves, or with flash, they disappear. The best bet is to search for them on nights when the bugs are active and in the right habitat.

I speculated that a thermal might help. But given how well these birds hide, how they can use torpor, I wonder if they'd stand out against their background with a thermal. I've learned how to find them but it still takes a fair amount of luck. If you see termites hatching out, that's a good time.

 

[nmerc_photos]

Shameless plug - if anyone wants my favorite thermal, the XP28 - I have one for sale for $2K.

I have 3 of them, and I think that's a bit much for redundancy sake. I also want to try out either some of the newer binos or an XL50 monocular, despite the narrower FOV.