July 2026 - Written by the HeatSight Optics Team
HeatSight TPM C19-640 35mm Review - The C19-640 35mm is the value pick of the 640 lineup: a full 640×512 sensor, a wide 12.5° field of view, and a 580-gram body at $1,199. If you're moving up from a 384 scope - or buying your first thermal and refusing to buy twice - this is where we point most callers.
A compact tube-style thermal at 580 g with a 35 mm manual-focus germanium objective and 2x base magnification, expanding to 2-8x with electronic zoom. Dimensions are 198 × 57.5 × 64.3 mm. It mounts like a day optic and disappears on the rifle compared to the 3-pound LRF flagships from the big brands.
Every C19 shares the same 640×512 VOx core: 12 μm pixel pitch, ≤40 mK NETD, ≤50 Hz refresh, 8-14 μm band, manual focus, and a sharp 1440×1080 OLED display - a meaningful resolution step over the 1024×768 eyepieces common at this tier. Six palettes (White Hot, Black Hot, Fire Hot, Rainbow, Iron Red, Cold Color), picture-in-picture, hotspot tracking, and five menu languages are standard. Recording is onboard: 16 GB storage (13.8 GB usable), JPG/MP4, USB charge and export.
Power is a pair of removable 18350 cells (1,400 mAh each) rated for 5+ hours at ≤1.8 W. 18350s keep the scope compact, but they're less common at the corner store than 18650s - buy two spare pairs with the scope and rotate them. The housing is IP66 and rated to 1000G of recoil, operating -20°C to +60°C.
This is the scope I recommend most and the field time backs it up. The 640 core finds heat a long way beyond where anyone should be shooting at night, and the 35mm view is wide enough to scan while walking without the soda-straw feeling. Hogs read as hogs, coyotes as coyotes, at distances where a 384 shows dots. It zeros easily, holds it, and the battery routine is two cells at dusk and forget about it.
Full 640×512 sensor at this price: Most competitors at this money are selling 384 cores.
1440×1080 OLED display: Sharper eyepiece image than the 1024×768 norm in this class.
Widest field of view in the C19 line: 12.5°×10° makes target acquisition fast on called predators at typical shot distances.
Compact and light: 580 g on the rifle, standard mounting.
For most hunters east of the plains states, the 35mm's field of view and 640 detail hit the sweet spot. Need ranging? The same scope with an LRF is $200 more. Shooting longer country? The 54mm and 75mm trade FOV for reach. 2-Year Limited Warranty, as with every HeatSight scope.
Specifications: 640×512 VOx, 12μm, NETD ≤40mK | 35mm, 12.5° × 10.0° | 2x base, 1-8x e-zoom | OLED 1440×1080, 0.39" | ≤50Hz | 6 palettes, PiP, hot tracking | 16GB, JPG/MP4, USB | 2×18350 1,400mAh, ≥5h | -20°C~+60°C | 1000G | IP66 | 198 × 57.5 × 64.3 mm | 580g
The HeatSight Optics TPM C19-640 35mm is available at heatsightoptics.com for $1,199 (regularly $1,499). It's in stock and ships from our Michigan facility. Questions about which HeatSight scope fits your hunting or property-security setup? Call us at (313) 338-8168 - you'll talk to the people who actually build and flash these units, not a call center.
This review was written by the HeatSight Optics team based on our own design, bench, and field testing of production units. We build these scopes, so consider the source - and consider that we also publish the cons, because we'd rather you buy the right scope than return the wrong one.