The latest iteration in the Burris clip-on thermal series, the all-new BTC35 V3 is a multi-function thermal system that earns its keep

by Rob Reaser

We’re all aware that thermal imaging is the hot ticket in the hunting and, to a smaller degree, the personal defense segments. This expanding technology, I believe, will likely soon surpass (if it hasn’t already) the more traditional night vision optic solutions not only due to thermal’s growing proliferation in the marketplace but also for its versatility. Thermal imaging offers 24-hour performance — from pitch black darkness to full-on sunlight — allowing the user to find targets in the dark as well as locate quarry or threats lurking in the deep, contrasting shadows of the day.

While thermal technology is continually being refined to deliver greater sensitivity, more advanced image processing for enhanced clarity and heat signature discernment, and expanding user options, we are simultaneously seeing the cost of these marvelous devices ratcheting downward as brands leverage scales of economy and competition among manufactures heats up.

Gotta love the machinations of free enterprise capitalism.

First Test: Burris Btc V3 Clip On Thermal

One company that has been making a full-force assault on the thermal optics arena of late is Burris. An optic concern steeped in America’s hunting heritage with its top-end magnified optics and innovative products like the Eliminator-series laser rangefinding riflescopes, Burris has embraced thermal imaging with handheld, clip-on, and riflescope thermal units. This year, the company has revamped its entire line of thermal devices with more contemporary designs and broader functionality plus improved menu navigation.

I recently got my hands on one of these new-for-2024 thermal units: the BTC35 V3.

Burris BTC35 V3 Clip-On

The BTC35 V3 is, as the name implies, the third generation of Burris’ thermal clip-ons. Clip-on, of course means that the thermal attaches to the objective bell of your rifle’s optical scope and can be quickly installed or removed depending on your needs.

Although I feel more confident in maintaining zero with a dedicated thermal riflescope (not that I’ve had any issues with my first-generation BTC50 maintaining zero), I do favor the clip-on variant because it serves a dual purpose.

First, and most obvious, it provides accurate imaging when used with an optical riflescope. When I want the precision and clarity of glass-only, I can remove it in a blink.

Burris BTC35 V3 Clip-On

Second, a clip-on can be used as a handheld thermal monocular. Granted, the display screen on a clip-on is necessarily smaller than that of a dedicated thermal monocular, but it gets the job done well enough for general observation or game tracking. I find this especially handy when coyote hunting because it eliminates the strain and fatigue of using a rifle-mounted thermal for observation. For me, it is much easier to use the clip-on as a monocular to locate incoming dogs than it is to scan behind a rifle-mounted thermal. Once a yote is spotted, it is a simple matter to re-affix the clip-on to the scope and get to work.

Burris BTC35 V3 Clip-On

Mounting the BTC35 V3 to your riflescope requires an adapter that is not included with the thermal unit. Called the Smartclip, it comes at a fairly steep $228 MSRP. The unit is made of aluminum and uses a cam lever to secure the adapter to the riflescope’s objective bell. Several models of the Smartclip are available for objective bells with outside diameters ranging from 30mm to 63.5mm.

Burris BTC35 V3 Clip-On

Installation of the Smartclip is simple. The front end screws onto the BTC35 V3’s eyepiece. The eyepiece locking ring is used as a sort of jam nut to secure the two components into the desired position.

Burris BTC35 V3 Clip-On

From here, the BTC35 V3 and adapter combination installs over the riflescope’s objective bell. Align the thermal unit level with the scope and secure with the cam lever. You will need to experiment with the Smartclip’s cam lever adjustment in order to get the optimal clamping force.

Burris BTC35 V3 Clip-On

The BTC35 V3 represents a significant design departure from the original BTC35. The unit is shorter yet wider and presents more flowing contours than its squarish predecessor.

Burris BTC35 V3 Clip-On

Part of the unconventional profile is credited to the somewhat “outboard” battery compartments located on either side of the back of the housing. Burris made these independent to allow for “hot-swapping.”

Two battery icons appear on the BTC35 V3’s display screen so you can monitor the charge levels of each battery. Should one battery need changed before the other, the depleted battery can be swapped for a fresh one without eliminating power going to the imager. Should both battery compartment doors be opened simultaneously, though, power will shut down across the unit.

The battery compartment doors open by depressing the integrated latches. This is one design change to the BTC35 series that hasn’t totally won me over. Yes, the latch system makes it fast and easy to change out batteries. At the same time, I feel that, lacking a locking mechanism, the latches could be easily bumped in the field, allowing the door to pop open and the battery to fall out of the housing. I didn’t experience this during testing, but then I was aware of this potential issue and was diligent in mitigating the possibility.

Burris BTC35 V3 Clip-On

The power source for the BTC35 V3 is two 3.7v ICR16340 rechargeable batteries or two CR123A batteries. Burris warns that the ICR16340 batteries are the best option for maximum performance.

Interestingly, these batteries are directly chargeable via the included USB-A to micro-USB cord.

Burris BTC35 V3 Clip-On

The BTC35 V3 also comes with a USB-C to USB-A/RCA cable. This configuration allows you to charge the batteries while in the unit (with the power off) and permits the unit’s display to be viewed on a larger external screen or sent to a DVR device.

Burris BTC35 V3 Clip-On

A big change for the new-generation BTC35 is the super-simplified controls. The four-button interface has been slashed to two. There is the expected power button that turns the unit on/off and activates/de-activates the standby mode.

The BTC35 V3’s extensive menu is accessed via the pushbutton/rotary dial knob located just behind the power button. This replaces the up/down/menu buttons of the first-generation Burris clip-ons, and I really, really like it. Pressing the button opens the main menu on the display screen and gives access to the following settings:

  • color palette
  • thermal settings
  • general settings
  • Wi-Fi settings
  • power settings
  • restore factory settings
  • screen position
  • screen adjustment
  • exit main menu

Rotating the dial moves between the primary settings when you’re in the main menu, then pressing the button accesses the sub-menu settings for each category.

This setup is much easier to change settings than scrolling through the menu with up/down buttons. No fumbling in the dark to hit the right button and no accidental setting changes because you hit the wrong button. Clean, simple, and efficient.

Another plus is that the rotary knob, when the menu is not displayed, lets you choose between 1x, 2x, and 4x digital magnification. With my gen 1 BTC, I often hit the menu button instead of the magnification button, and that throws me off when trying to quickly zero in on a moving critter.

Burris BTC35 V3 Clip-On

While the BTC35 V3 is fully self-contained in terms of operation, like all of Burris’ electronic technology-driven products, the BTC35 V3 can also tie into the Burris Connect app installed on your mobile device. The app gives you access not only to several of the thermal unit’s settings, but it is the means by which you can capture still images and record video through the unit and store them on your mobile device.

Burris BTC35 V3 Clip-On

Imaging and video recording become available when you select the streaming option. This live-streams the image direct to your mobile device, where you can adjust viewing settings and capture stills and video.

First Test: Burris Btc V3 Clip On Thermal

The night I got the BTC35 V3, I selected a reticle (you can choose between 10 different reticle styles) and activated the picture-in-picture mode (this can be placed left, right, or center) and headed out to see what I could see. First up was a coyote or a fox cruising the field edge. He wasn’t letting any moss grow under his paws, so panning the unit as the critter trotted along the field gave me a chance to test the 50 Hz frame rate (equal to 50 frames/second). The BTC35 V3 tracked true with no disconcerting lag or blurriness.

Burris BTC35 V3 Clip-On

Next, the big buck I was chasing all last fall (obviously without success) showed up, much to my delight. This shot was taken at 4x magnification. As you can see, the BTC35 V3’s 400×300 detector resolution and 12 μm pixel pitch combined with the 1024×768 OLED display delivers a functional image you can work with in the pursuit of varmints after dark.

Burris BTC35 V3 Clip-On

Zeroing the BTC35 V3 presented no challenges for me, and it won’t for you if you follow the manual’s screen alignment and zeroing instructions. Burris incorporated a new RapidZero program that makes the process a bit easier than my experience with the original clip-on.

Since the clip-on type allows you to easily swap the unit between rifles — say, your .223 for coyote hunting and your .350 Legend for hogs — the BTC35 V3 lets you store multiple reticle/zeroing profiles. Assuming your scopes have the same objective bell size, or you fork over the dough for individual adapters, you can set up the BTC35 V3 for up to six different profiles.

Burris BTC35 V3 Clip-On

As mentioned earlier, the BTC35 V3 clip-on is a diverse thermal unit that works as a hunting as well as an observation tool. Beneath the housing is a 1/4-20 threaded bushing to accept tripod heads. I’ve been using my Outdoorsmans standard tripod and pan head to support the BTC35 V3 as I watch my buck’s antlers get bigger and bigger this summer.

First Test: Burris Btc V3 Clip On Thermal

When it’s time to hit the coyote fields, the BTC35 V3 is ready to transition from big buck dreaming to varmint busting in no time flat.

With an MSRP of $3,000, the BTC35 V3 is an investment. But if you are looking for a thermal unit that provides 24/7, 365 functionality — whether for hunting, observation, or keeping an eye on things around the homestead — it is an investment that will quickly pay for itself.


Shoot On Editor-in-Chief Rob Reaser is a lifelong outdoorsman, former magazine editor, columnist, and contributing editor to numerous national publications in the automotive and outdoor segments. He has also authored and co-authored several DIY gun building books. His shooting and hunting passions cover everything from traditional archery and big-game bowhunting to the latest in handguns, rifles, and reloading. Rob has a troublesome habit of pulling guns and things apart to see how they work; occasionally, he manages to get them back together...

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