Burris BTS35 v3 640
640×480 · 12 µm · 35 mm · 6 h · MSRP $4,200
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Coyote at 100 yd
18 px tall at the shoulder
Coyote at 200 yd
9 px tall at the shoulder
Coyote at 300 yd
6 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.
~150 yd
The same as 75 of the 207 other current thermal scopes we track; 76 reach farther.
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.
66 ft
Wider than 73% of the 208 current thermal scopes we track (tied for #26).
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. | 640 × 480 |
| 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. | 12 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. | <30 mK |
| 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/1.0 |
| 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. | 2× |
| 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. | 16× |
| 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. | 12.5° × 9.4°Field of view 12.5° x 9.4° from the spec table and the manual (the product page's feature list repeats the 400 model's 7.8° x 5.9°, a copy error). Base magnification 2.0x is the manual's optical zoom (the page's '14x' is the eyepiece magnification); the 16x top end is calculated as 2.0x times the published 1x-8x digital zoom. NETD published as ≤30 mK. Detection is Burris's deer figure (1,000 m / 1,100 yd), the same as the 400 model. |
| 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. | 1,094 yd |
| 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 | 18650 (1 internal + 1 removable), 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. | 6 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. | Yes |
| 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. | 800 G / 1 ms |
| 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. | QD M1913 Picatinny mount (American Defense Mfg) with adjustable cantilever, included |
| 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. | 27.2 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. | -4°F to 122°F |
| 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 |
| 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. | Not found |
| 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. | $4,200MSRP on the Burris BTS35 v3 640 product page, October 11, 2026 |
Source: Burris BTS35 v3 640 product page (spec table), Burris BTS v3 user manual (PDF, technical specifications for BTS35v3-400 and -640), Burris warranty page (thermal warranty).
Added October 11, 2026 · Specs last checked October 11, 2026
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400×300 · ID ~150 yd · 41 ft wide at 100 yd · discontinued
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