Test + video: Nitehog TIR-M35 Chameleon X-Core hunting clip-on thermal imaging optic – The second generation 2021

the new Nitehog TIR-M35 Chameleon X-Core multifunctional clip-on thermal imaging optic
We tested the new Nitehog TIR-M35 Chameleon X-Core multifunctional clip-on thermal imaging optic with a GECO Black 1-6x24i daytime riflescope mounted on a Benelli Argo E-Pro semiautomatic rifle.

We received a sample of the Nitehog TIR-M35 Chameleon X-Core multifunctional hunting clip-on thermal imaging optic, built by German based company Nitehog Europe GmbH – we wrote about it here. The Nitehog Chameleon X-Core is a self-contained thermal imaging module that can be used stand alone, as a capable hand-held observation monocular with 1x magnification and up to 4x digital zoom, or a Thermal Imaging clip-on conversion optics that, when mounted in front of a daytime riflescope with an optional adapter, allows the riflescope to be used as a thermal imaging aiming device system.

The claims that this European hunting sports optics manufacturer makes on the Chameleon X-Core are impressive, and we wanted to thoroughly test the device to find out if the marketing promises and hype are real. Spoiler alert: they are.

The Nitehog TIR-M35 Chameleon X-Core model 2021 + adapter kit

the front objective
The Nitehog TIR-M35 Chameleon X-Core clips on the front objective bell of the daytime riflescope.

We received the TIR-M35 Chameleon X-Core thermal imaging optic module in a sturdy and rugged black polymer storm case, with a complete accessory set, including a plastic eyepiece adapter ring, a threaded riflescope adapter interface ring, and the correct adapter for a 30 mm diameter objective bell, to allow the Chameleon X-Core to be mounted in front of our Geco Black 1-6x riflescope

the Nitehog TIR-M35 Chameleon X-Core module with the rubber ring 
Here’s the Nitehog TIR-M35 Chameleon X-Core module with the rubber ring used to protect the clip-on threaded interface when the Thermal Imaging device is used as a standalone observation monocular. Note the proprietary 7 pin Fischer connector.

The kit also includes the Battery extender, which integrates a rechargeable Li-Ion cell that powers the Chameleon for more than 4 hours of continuous operation; the thermal imaging device can be also powered by two CR123A standard Lithium batteries. The kit is completed by a very clear and exhaustive manual, a wall charger, some cables and ancillary accessories.

But let’s take a look at the basic system. The TIR-M35 Chameleon X-Core is built out of a CNC machined billet of strong, resilient and lightweight Magnesium alloy; the manufacturer claims IP66 waterproof certification and fog proof nitrogen filling.

The focusing ring in front of the device seems made of some hard plastic and is a bit thin and sharp in front, extending for a couple centimeters in front of the Germanium lens, to protect it from harm. The fast, F1.2 aperture objective lens has a focal length of 35mm, and the surface of the Germanium element is treated with a scratch-resistant, hard Carbon coating; the lens allows for a 17.7x13.3° field of view.

two CR123A standard Lithium batteries
The Chameleon X-Core is powered with either two CR123A standard Lithium batteries or a provided Battery extender, with a rechargeable Li-Ion cell. Both options can power the Chameleon for more than 4 hours of continuous operation.

The interface on top of the housing includes just three buttons, while the power on/off control is actually a mechanical lever, placed on the left side. A nice touch is the use of luminous painted indicator, so it can be found easily by its “glow in the dark” effect. Just above the power switch, we can find the waterproof battery compartment, closed with a tethered cap, which has to be removed to use the battery extender.

On the right side, a proprietary 7 pin Fischer connector handles both USB links and A/V output for external recording; optional cables are needed to connect to it.

The Nitehog Chameleon X-Core with the clip-on adapter
The Nitehog Chameleon X-Core with the clip-on adapter, built by Rusan, and the eyepiece protection. A nice touch is the use of luminous paint on the power switch, so it can be found easily by its “glow in the dark” effect.

The eyepiece is actually an afocal relay lens system that offers no diopter adjustment, but thanks to the very wide angle afforded by the eyepiece and its long eye relief, prescription glasses users will have no problem observing the digital thermal image presented by the OLED microdisplay. As this is the second generation Chameleon thermal imaging device from Nitehog, it is based on the proprietary, in-house built, high performance Nitehog X-Core image processing module, featuring a higher resolution, amorphous Silicon (a-Si) LYNRED-built 17 μm pixel pitch Focal Planar Array sensor capable of 640x480 resolution, a dramatic improvement on the previous generation 336 x 256 Pixel resolution sensor. The full color, 800x600 pixel resolution AMOLED display can function at extreme temperatures, that are to be expected during hunting activities – especially, various degrees sub-zero freezing cold.

Fieldtest: operating the TIR-M35 Chameleon X-Core

three buttons on the top of the device
The user interface includes just three buttons on the top of the device. There is no diopter adjustment, and focus is done via a objective focus ring.

We first tested the Nitehog Chameleon X-Core as a simple, monocular hand-held observation scope, with the eyepiece ring installed; this ring serves only the purpose of protecting the threading on the optical relay from damage and offering a face and glasses-friendly surface when the user looks into the device. At first, the afocal image may be a bit disconcerting, however, the image is sharp, and prescription glasses users have no problem. Turn-on time is less than five seconds; the three-button user interface is extremely simple to operate.

The Nitehog TIR-M35 Chameleon X-Core optic
The Nitehog TIR-M35 Chameleon X-Core optic can be used as a standalone thermal imaging hand-held observation device.

Each button is dual use, and depending on how long a button is pressed, or the combination of buttons pressed at the same time, it allows for white-hot or black-hot operation, brightness setting, entering the menu and setup and so on. One thing that is interesting is how immediate and simple the interface is. It certainly does not distract from the hunt; only what is needed is present. To be used as a monocular the Chameleon X-Core, the user must ensure that the correct menu option is selected; in clip-on mode, some functions (such as digital zoom and Menu item size) are disabled.

There is the possibility to record up to 20 still images inside the device, but to record video, or to connect to wifi smart devices, optional external modules and/or cables are needed.

The Nitehog TIR-M35 Chameleon X-Core
The Nitehog TIR-M35 Chameleon X-Core configured as a daytime riflescope clip-on thermal imaging device, with the Battery extender mounted.

From the usual infinity, the minimum focusing distance of our sample device, is a surprising 50 cm! We could focus on extremely close objects, to observe all their most minute details. We used the Nitehog Chameleon X-Core as handheld device in a few walks in the woods, in full daytime and at night. Results are good, with excellent contrast in all situations. 

At 4x, the image is quite grainy, mostly due to the relative displayed resolution on the screen dropping to just 160x120, but absolutely useable, also due to the good quality of the AMOLED microdisplay. The image processing firmware allows three different environment settings to enhance the image (hot, normal and wet) plus three additional filters to reduce speckle noise; there is also the possibility to choose among six different color palettes.

Video / fieldtest: Nitehog TIR-M35 Chameleon X-Core model 2021


Using the TIR-M35 Chameleon X-Core in Clip-On mode with a riflescope

The Rusan adapter
The Rusan adapter is built for a specific diameter, in our case 30mm, and provides a very reliable and strong clamp to the daytime riflescope.
The battery extender 
The battery extender does in fact increase the width of the Chameleon X-Core considerably, however it is very useful – and can be swapped with a second battery extender in seconds.

We mounted the Nitehog TIR-M35 Chameleon X-Core on a Benelli Argo E-Pro self-loading hunting rifle chambered in .30-06, using a GECO Black 1-6x24i variable magnification daytime riflescope, mounted on the gun with medium height rings; the mounting hardware choice is mandated by the bulk of the Chameleon body, to avoid touching the barrel or, in our case, the rear Carbon fiber sight ramp. The target we used is an all-black Varmint Birchwood Casey NC Target; we exposed the target to the sun, using a light colored cardboard backing, expecting that the black target will increase substantially its temperature, making it visible through thermal imaging devices. We zeroed the rifle at 100 meters, using the highest magnification setting (6x) of our scope and GECO ammunition, getting a nice 25 mm diameter three round group: that’s about 1 MOA accuracy, folks. Then, we slipped on the Chameleon X-Core configured with the Rusan-built adapter on the 30 mm “bell” of the riflescope and tightened, without any other adjustment. We let three more rounds fly on the target, and we’ve been surprised to find that, although our group opened up to about 6 cm, the center of the group was horizontally dead on, and just three centimeters high. Only a single click of the adjustment was necessary to center the group on the one obtained with the daytime riflescope alone.

The clip-on adapter is built for a single objective bell diameter and has a cost of approximately 150 euro. It is used with the included double threaded ring that locks it on the Chameleon body.

The mounted Chameleon X-Core system
The mounted Chameleon X-Core system adds a bit of weight to the riflescope and makes the firearm muzzle heavy; this is shared by all similar clip-on systems, and does not influence cheek weld and eyebox of the original scope. Rifle: Benelli ARGO in caliber .30-06. Daytime riflescope: GECO Black 1-6x24 i.

Now a note on the practical use of clip-on thermal devices: the optical relay that interfaces with the front lens of the daytime riflescope presents the image as a 1x image displayed on an AMOLED screen, and the riflescope magnifies this image, “zooming in” on the screen, and the higher the magnification, the bigger the pixels will appear – losing resolution. A good trade off is about 3x, and that is what Nitehog suggests as the highest magnification to use. That is also the reason our target groups got larger.

We repeatedly removed and remounted the Nitehog clip-on system to the riflescope and noticed no appreciable shift of zero in all our testing.

Wielding the firearm with the mounted Chameleon X-Core system in a hunting situation
Wielding the firearm with the mounted Chameleon X-Core system in a hunting situation is still perfectly comfortable, and it takes just minutes to adjust to the shift of balance.
The Chameleon X-Core system on a .30-06 Benelli Argo E-Pro semiauto rifle
We shot the Chameleon X-Core system on a .30-06 Benelli Argo E-Pro semiauto rifle at 100m distance from the bench, using GECO ammunition.
The Nitehog/GECO/Benelli Argo platform from the ground
We also tested the Nitehog/GECO/Benelli Argo platform from the ground, and standing simulating different hunting scenarios.
Our group at 100m after a good zero of the GECO Black 1-6x24i riflescope
Our group at 100m after a good zero of the GECO Black 1-6x24i riflescope (we had to rezero due to a change of mounting rings): 25mm diameter, three rounds.
The Chameleon X-Core on the daytime riflescope
We then installed the Chameleon X-Core on the daytime riflescope and from the same position shot another three rounds. This is the result: about 6cm, three cm higher than the daytime riflescope-only group.
The view from the eyepiece of the daytime riflescope
The view from the eyepiece of the daytime riflescope. The image is much better than we see here, and it is actually very easy to see the black varmint rectangle in the center of the IPSC/USPSA target.

To wrap it up: our opinion is positive. We believe all claims from the manufacturer have been met, and in the end, Nitehog staff include hunters, that build optics specifically for hunters. The Nitehog TIR-M35 Chameleon X-Core system is extremely easy to use, and at least in our sample, clip-on accuracy is actually enough in our opinion to be used in driven hunts (up to 25-35 m) as is, without additional in-scope adjustment; quality and performance is very good for its price range. MSRP for the Nitehog TIR-M35 Chameleon X-Core multifunctional clip-on thermal imaging optic is set at 4699 euro (this price includes the rechargeable Battery extender and wall charger); price in other EU countries may be different due to local VAT and taxes regulations. However, the Promotional price for the introduction of the new generation Chameleon with X-Core is 3600 Euro, for a limited time only!

Legal reminder: in case the Nitehog device is used as an attachment on a firearm, all legal regulations of the weapon law and the respective national hunting law must be respected. 

For additional information please visit Nitehog website. Distributor in most EU countries is RUAG Ammotec.

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