Thermal "spotting scopes" - the experience thread (1 Viewer)

Vollmeise · Dec 20, 2017

There are several older and some newer posts in different categories of the forum relating to thermal imagers and their possible benefits for birder's needs.

I read lots of could-ones, would-ones and should-ones but also found valuable hints and information here and there.

Precisely because this information is widely scattered and well hidden, I'd like to pull it all together in a new thread where all these questions, answers, experiences, practical hints and news will be collected and found for those who are interested.

So, here's my warm welcome :flowers:

Vollmeise · Dec 20, 2017

First impressions with the Pulsar Helion: Part I

As written in another thread, my first serious interest in using a thermal imager side by side with traditional sport optics aroused by Suan Hsi Yong's infrared-birding blog. I just can say "Thank You" for his commitment:

http://infrared-birding.blogspot.fr/p/welcome-to-infrared-birding.html

His impressive experiences made me searching for any information available. Though there is some footage (youtube, vimeo and ohers) made with different thermal devices, these mainly focus on security issues or on hunter's needs.

The most important insight I required was that amongst hunters the use of thermal imagers seems to be quite common since these devices became both powerful and affordable.

And that's why I did find myself in a hunter's shop one day holding some of the latest thermal imagers in my hands and ready to form my own impressions.

Even the very first view through these thermal imagers made me thinking: "Wow, how sensitive are these beasts!". Some customers walking through the shop (normal speed, with boots on) left their thermal marks as clearly visible footprints on the ground, dissappearing after some seconds. Outside I coud see cormorants flying past and sparrows in a hedgerow nearby. While almost the whole plumage looked well insulated, their head and especially their eyes kind of "glowed" and made it easy to see them at once.

Such a thing will surely help finding pipits, jack snipes, grouse, woodcocks, bitterns, night jars and all of these wonderful birds found by accident in the last years only.

So, here are some pics of the new baby I'm going to talk about in one of the next posts:

Torchepot · Dec 21, 2017

Hi Vollmeise Thanks for this

Could I ask you a favour? Lots of people have never seen the device "in the flesh" and it's hard to judge the exact size and proportions from reading the specs (at least for me!) Could you provide another photo of the imager in the hand sideways on please? (Or perhaps in the palm of your hand?).

Also a shot of the underside showing the mounting would be useful too :t:

Cheers

Phil

Vollmeise · Dec 21, 2017

Torchepot said:
(...)Could you provide another photo of the imager in the hand sideways on please? (Or perhaps in the palm of your hand?).
Also a shot of the underside showing the mounting would be useful too :t:

Here are some more quick and dirty photos, showing its size in my hand and its mounting thread (1/4").

Some more photos, especially the lining up with a spotting scope side by side on a tripod You'll see in one of the next posts. The ordered accessory parts for the setup above just were delivered yesterday, so I need some time for that.

Its weight ready to use (exactly as shown, with 50mm lens and attached LiIon battery pack) is 561 grams.

Cheers

Torchepot · Dec 21, 2017

Thanks Vollmeise :t:

Looking forward to your comparison of the two lenses.

Cheers

Phil

Vollmeise · Dec 21, 2017

Torchepot said:
Thanks Vollmeise :t:

Looking forward to your comparison of the two lenses.

Phil

Me too, the 28mm lens is ordered and maybe on 27.12. the first comparisons can be made.

Cheers

Hauksen · Dec 21, 2017

Moin!

Vollmeise said:
Me too, the 28mm lens is ordered and maybe on 27.12. the first comparisons can be made.

I'm looking forward to a report on how the lenses compare in the field

At the longer observation distances typical for Northern Germany, I'd expect the longer lenses to be more useful as you'd probably be scanning the horizon in a wide sweep, but from the blog you linked, in wooded environments where you'd like to cover a greater arc, the shorter lenses appear to be more practical.

Tschüs!

Henning

Vollmeise · Dec 27, 2017

Helion 28mm lens, unpacking!

This morning the ordered 28mm lens arrived, so let's share my very first impressions with some pictures.

Shown is the 28mm lens in its case and it's dimensions compared with the Pulsar Helion XP body and 50mm lens.

Cheers

Vollmeise · Dec 27, 2017

Pulsar Helion with 28mm and 50mm lenses - trying out at home

Well, though there are some sources describing the different lenses, I was very curious about the shorter lens' look and feel and it's possible uses.

First I took an electronic scale to compare the weight of the devices by my own:

Pulsar Helion XP, body with battery, no lens: 429g
Helion 28mm lens: 94g
Helion 50mm lens: 135g

At their front end both lenses carry a hinged lens cap. While the 28mm lens cap snaps and fits with a nice "click", the 50mm lens cap has an integrated o-ring seal that requires some more pressure to close it and this door-closing even feels a bit fuzzy - there is no haptic feedback if the cap is closed properly or not.

The bayonet mount of both lenses also carries an integrated o-ring seal to tighten the connection between body and lens. The lenses focus ring turns smooth, no difference between 28mm / 50mm lens.

Let's place the new lens to the body!

First big surprise: the minimum focus distance is way shorter than all of the circulating information made me beleive.

Turning the focus ring all the way (about 350 degrees starting from infinity) clockwise you get a pin sharp image at 0.95 m with the 28mm lens (measured from front lens, see image of the water tap).
The minimum focus distance of the 50mm lens is 7.00m, also measured from the front lens. It’s focus ring turns just about 135 degrees.

So walking around and searching for ground-breeder's nests should be no problem at all regarding focus.

The attached photos show some indoor use at close focus with the 28mm lens attached. Hot = white. (The shown magnification factor at the water tap picture is wrong, it should be 1.4x. That happened because I forgot to change the settings from 50mm to 28mm in the devices setup)
Please remember: the shown pictures are visibly worse than the image of the view finder. Hope the manufacturer will improve this issue one day.

So, within the next days I'll take the Pulsar outdoors and will post my impressions. Keep on watching and any feedback welcome!

Cheers

Torchepot · Dec 27, 2017

Very good news about the CF - great for searching for small mammals too. Remarkable resolution - looking at the image of the mixer tap - it's practically photographic quality!

With the combination of those two lenses you've got everything covered :t:

Vollmeise · Jan 10, 2018

Thermal spotter in daily use: some samples

Hi there again,

meanwhile I could try out my new toys during a one week trip along the German North Sea coast. The following posts will show three images each: an overview made by my iPhone first, the view through the thermal imager (green rectangle) second and the last image phonescoped (red circle, Kowa 883 w/ iPhone SE).

First sample: common shelducks on a sunny afternoon. Note the numerous tiny white spots on the thermal image.

Vollmeise · Jan 10, 2018

Next location. I just scanned the grassland and could find another tiny white spot with the thermal spotter (center of the thermal image). First: overview, second image: thermal image (green rectangle), third image: a resting common snipe (red rectangle).

The thermal imager and the spotting scope both are mounted on a rig, the view's centers are aligned.

Vollmeise · Jan 10, 2018

At the next location, just some hundred meters further on, you can see the overview first, followed by a thermal image using the 28mm lens (large green rectangle). Almost 40 tiny white spots can be seen there. The next image is made with the 50mm 5ermal lens (smaller green rectangle) and the last pic shows some of the 42 Eurasian Golden-Plovers lately.

etudiant · Jan 10, 2018

Vollmeise said:
At the next location, just some hundred meters further on, you can see the overview first, followed by a thermal image using the 28mm lens (large green rectangle). Almost 40 tiny white spots can be seen there. The next image is made with the 50mm 5ermal lens (smaller green rectangle) and the last pic shows some of the 42 Eurasian Golden-Plovers lately.

Impressive performance, seems a very powerful tool for finding birds that are otherwise inconspicuous, even in daylight.
Presumably it was pretty cold. Any idea of the ambient temperature?

Vollmeise · Jan 10, 2018

etudiant said:
(...) Any idea of the ambient temperature?

Hi etudiant, temperature was around +5°C and birds could be detected both in cloudy and sunny periods of time, as long as the habitat’s surface was homogenous. If there are lots of bird sized heights in the terrain (soil, stones), the sun will heat these protunding parts and finding birds is much more difficult or impossible. Spring and summer time surely will provide new conditions and findings.

Vollmeise · Jan 10, 2018

Here some more images, a grey heron searching for food and in flight seen in the nighttime and some barnacle geese in daylight. Each photo made wih 28mm lens attached.

Hauksen · Jan 10, 2018

Moin!

Vollmeise said:
First sample: common shelducks on a sunny afternoon.

Beltringharder Koog, Speicherbecken, looking towards the Hamburg Hallig? Looks you had a brilliant day!

Vollmeise said:
First: overview, second image: thermal image (green rectangle), third image: a resting common snipe (red rectangle).

I'd say that would have been pretty much impossible to spot without a thermal imager.

Vollmeise said:
Each photo made wih 28mm lens attached.

Did you have both lenses along for a comparison? Looks like the 28 mm lens is a very good choice for Northern Germany, though.

Thanks a lot for sharing, this is highly interesting!

Regards,

Henning

Vollmeise · Jan 10, 2018

Hauksen said:
Beltringharder Koog, Speicherbecken, looking towards the Hamburg Hallig? Looks you had a brilliant day!

Right, we had a beautiful week there, with very mixed weather impressions

Hauksen said:
I'd say that would have been pretty much impossible to spot without a thermal imager.

I could find three common snipes in that area (Hallig Hooge), without the thermal imager we definetly had not seen one of them. I hoped to find Jack Snipes, but had no luck. When searching birds within far distances (100-500m) it's very important to use a tripod and have the view of your thermal / spotting scope well aligned, otherwise you won't find passive birds like a resting snipe.

Walking around with the handheld imager works fine within distances up to 50m, using the 28 lens. When there is a white spot, you'll get the bird with your bins.

Hauksen said:
Did you have both lenses along for a comparison? Looks like the 28 mm lens is a very good choice for Northern Germany, though.

I had both lenses with me and yes, the 28mm is a sharp and versatile tool to start with.

Cheers

Torchepot · Jan 11, 2018

The 28mm lens is impressive - with it's wider field of view and better close focusing. It doesn't seem to lose out to the 50mm much over most distances.

I wonder in how many situations the 50mm would have the advantage.

From my spotlighting days I remember someone turning up with a super powerful light which often showed eyeshine on animals that were so far away it was impossible to identify them - which proved very frustrating if the terrain didn't allow a closer approach.

Bartgeier · Mar 5, 2019

Very interesting, Vollmeise!

Can you share your experiences with summer-time use? Also did you give it a try for other species like bats?

Thermal "spotting scopes" - the experience thread (1 Viewer)

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