Thermal scopes / BurrisDiscontinued
Burris BTS 35
400×300 · 17 µm · 35 mm · 3 h · MSRP $3,899
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Coyote at 100 yd
13 px tall at the shoulder
Coyote at 200 yd
6 px tall at the shoulder
Coyote at 300 yd
4 px tall at the shoulder
Identify a coyote out to
Identification distance
Our estimate of how far away you can tell a coyote from a fox or a dog. It is calculated from the lens and sensor, assuming good conditions.
~105 yd
Farther than 8% of the 208 current thermal scopes we track (tied for #154).
Ground across the screen at 100 yd
Field width
How many feet of ground fill the screen at 100 yards. Wider makes scanning faster; narrower usually means more detail on the animal.
58 ft
Wider than 66% of the 208 current thermal scopes we track (tied for #69).
Specs
| Sensor | |
|---|---|
| Resolution Sensor resolution How many heat-reading pixels the sensor has, such as 384 × 288 or 640 × 512. More pixels show more detail, but the lens matters just as much. | 400 × 300 |
| Pixel pitch Pixel pitch The size of each sensor pixel, in microns. Smaller pixels mean more magnification from the same lens. Most current thermals use 12 microns. | 17 µm |
| NETD (maker’s claim) NETD (thermal sensitivity) How small a temperature difference the sensor can show. Lower is better, but brands measure it differently, so numbers from two makers are not a fair comparison. | — |
| Refresh rate Refresh rate How many times per second the picture updates. 50 or 60 times a second looks smooth; lower rates stutter when you pan or a coyote runs. | 50 Hz |
| Optics | |
| Lens Focal length The lens number in millimeters, like 35 mm or 50 mm. A longer lens puts more pixels on a distant animal but shows a narrower slice of ground. | 35 mm f/1.2 |
| Base magnification Base magnification How much bigger things look before any digital zoom, like 2× or 4×. Higher is not automatically better: it narrows your view. | 1.7× |
| Max digital zoom Digital zoom Electronic enlarging of the picture. It makes the animal look bigger but adds no detail; past about 2× to 4× the image gets blocky. | 6.8× |
| Field of view Field of view How wide a view you get, in degrees. A wide view makes scanning for animals faster; a narrow one usually means more magnification. | 10.7° × 8°Magnification conflict: the BTS user guide gives 1.7-6.8x for the 35 mm model; the BTS50 product page gives 2.3-9.2x, the same figures Burris publishes for the 35 mm Thermal Handheld. The scope's own manual is used. Digital zoom is published as 2x, 4x. |
| Detection range (maker’s claim) Detection range The maker's figure for how far away a warm object shows up as a dot or two. It is far longer than the distance you can tell what the animal is. | — |
| Display | |
| Display Display resolution How many pixels the small screen inside the eyepiece has. A sharp screen looks cleaner but cannot add detail the sensor did not capture. | OLED 1024 × 768 |
| Power | |
| Battery | 1 x 18650, removable |
| Runtime Battery life (runtime) How many hours the device runs on a charge, by the maker's test. Real runtime is shorter in the cold and with Wi-Fi, recording or the rangefinder on. | 3 h |
| Features | |
| Rangefinder Laser rangefinder A built-in laser that measures how far away the animal is. The rated range is for big, reflective targets; expect much less on a coyote. | No |
| Storage Onboard recording (storage) Built-in memory that records photos and video of what you see. Useful for reviewing shots and sharing hunts; listed in gigabytes. | — |
| Wi-Fi / app Wi-Fi and app A wireless link to a phone app for live viewing, downloading videos, changing settings and updating the device's software. | — |
| Riflescope | |
| Eye relief Eye relief How far your eye sits behind the eyepiece and still sees the full picture. On a rifle scope, more distance keeps the scope off your face under recoil. | 48 mm |
| Recoil rating Recoil rating How much rifle recoil the maker says the scope can take and still work and hold zero. Makers state it in different units, so compare carefully. | — |
| Mount Mount How the scope attaches to the rifle: standard rings or a rail clamp, fixed or quick-detach. A good mount does more to hold zero than anything else. | Picatinny rail |
| Ballistic calculator Ballistic calculator Software in the scope that moves the aiming point for distance, using your bullet's data and the range to the animal. | — |
| Zero profiles Zero profiles Saved sight settings for different rifles or loads. Switch profiles instead of re-zeroing when you move the scope or change ammunition. | 6 |
| Build | |
| Weight Weight How heavy the device is. Check whether the maker weighed it with or without the battery, because brands do it differently. | 23.2 oz |
| Water rating IP rating (water rating) A two-part code for how well the device keeps out dust and water. IP67 means dust-tight and survives a short dunk; an X means not tested. | IP67 |
| Operating temp Operating temperature The temperature range the maker says the device will work in. Batteries lose much of their runtime well before the low end of that range. | Not published |
| Buying | |
| Warranty Warranty How long the maker promises to repair or replace a faulty unit. Check whether it needs registration and whether it passes to a second owner. | 3 years (current Burris US thermal warranty) |
| US price US price The price we found for the unit in the US, with where it came from and when. Prices change often, so treat it as a snapshot. | Discontinued |
| MSRP MSRP The maker's suggested retail price in the US: the list price, before any sale. Useful for seeing how good a deal really is. | $3,899MSRP on the Burris BTS50 product page (shared by the BTS 35 and BTS 50), marked discontinued, October 11, 2026 |
Source: Burris BTS50 product page (BTS 35 and BTS 50 spec table), Burris Thermal Riflescope user guide (PDF, technical specifications), Burris warranty page (thermal warranty).
Added October 11, 2026 · Specs last checked October 11, 2026
Current models to compare
In production now, near the BTS 35's last price.
- Athlon Cronus ATS 50-400$3,625
400×300 · ID ~210 yd · 29 ft wide at 100 yd
Compare with the BTS 35 → 384×288 · ID ~150 yd · 39 ft wide at 100 yd · rangefinder
Compare with the BTS 35 →384×288 · ID ~105 yd · 55 ft wide at 100 yd
Compare with the BTS 35 →400×300 · ID ~150 yd · 41 ft wide at 100 yd · rangefinder
Compare with the BTS 35 →
Other Burris BTS (Thermal Riflescope) models
Other sizes and versions in the same line.
- Burris BTS35 v2MSRP $3,000
400×300 · ID ~150 yd · 41 ft wide at 100 yd
Compare with the BTS 35 → - Burris BTS35 v3MSRP $3,000
400×300 · ID ~150 yd · 41 ft wide at 100 yd
Compare with the BTS 35 → - Burris BTS 50MSRP $4,199
400×300 · ID ~150 yd · 41 ft wide at 100 yd · discontinued
Compare with the BTS 35 → - Burris BTS35 v3 640MSRP $4,200
640×480 · ID ~150 yd · 66 ft wide at 100 yd
Compare with the BTS 35 →