In October 2021, Swarovski Optic announced the tM 35, its first and long-awaited foray into the fast-growing thermal imaging market. After an eight-month wait, shipments have now arrived in the UK. The new tM 35 functions as an observation monocular and a clip-on device to add thermal functionality to the Company's renowned optical rifle scopes.
Upon opening the box, what immediately strikes you is the compact design of the tM 35. The unit is 170mm in length, 54mm in width and 80mm in height, including the battery housing. It weighs in at 495g. The tM35 is supplied with a quality field bag, wrist and neck straps, a compact charge unit, battery, a winged eye cap, lens caps and cables.
The rechargeable Li-lon 3000 mAh Battery is inserted into the top of the unit and provides seven hours of operation. There is a button on the left-hand side to switch on the device. During the two sec start-up time, a splash screen of the Swarovski logo is displayed, the ambient light conditions are analysed, and the intelligent control automatically adjusts the screen of the tM 35 to one of 32 brightness levels. The unit is dimmed at night to avoid dazzling when viewing in dark light conditions.
Two key components of thermal imagers are the thermal sensor and the screen display. When the tM35 was launched, some observed that the Uncooled VOx microbolometer with 320x256 sensor resolution and 12(µm) pixel size was less than some other high-end products. However, the AMOLED display screen with 2560x2048 pixel resolution is market leading. When the thermal unit is attached to the scope, and the optical zoom on the scope is used rather than a standard digital zoom, the image quality is excellent. The scope is optically zooming in on the high-resolution screen. When using an optical zoom in front of a lower resolution display screen, the image quality is compromised regardless of the thermal sensor's resolution. Swarovski engineers have managed to get the sensor to screen display equilibrium just right.
For those who have used other thermal devices, the pure simplicity of the tM 35 is apparent. There are no complex menus. There is a simple menu bar which appears for 5 sec when any button is pressed. One of the three buttons on the top of the tM 35 changes the mode from Black Hot to White Hot. The other two buttons manually adjust brightness levels if a user wishes to fine-tune the intelligent control setting. The tM 35 also has a memory function in the day, twilight, and night range. If your selected brightness level in one of the three ranges differs from the default setting, the tM 35 will save this custom brightness setting and apply it when the device is next activated or switched on.
The tMA thermal monocular adapter (purchased separately) easily converts the handheld device to a clip-on scope device. The tm 35 attaches to the adaptor with a screw thread. The thermal unit and adaptor attach to the scope by placing the conical-shaped sleeve over the front of the scope and securing it with a tensioning lever. The process takes a few seconds and can be undertaken in darkness. The adaptor sleeve includes protection to prevent scratching the scope casing.
As a thermal monocular, the tM 35 fits nicely in the hand and is small enough to fit into a jacket pocket. In observation mode, the unit operates in 4x digital multiplication. The image quality is satisfactory but not the best in class. The tM 35 comes into its own on the front of a scope. In tests, the thermal provided excellent target resolution at up to 10x optical zoom on a Swarovski Z8i 2.3-18x56 scope complemented by an illuminated 4A-300i reticle.
Attaching a device to an optical hunting scope can affect the point of impact. Would attaching the tm35 to a quality scope affect the point of impact? A trip to the range was the only way to settle Swarovski's claim of a 100% reliable point of impact.
The first test at the range was to check zero at 100m with the Z8i scope on a 6.5 Creedmoor rifle. A 3 shot group produced a sub-0.5 inch group. The tM35 was attached to the scope and a 3 shot group fired at the same target with an added heat source. Despite a more challenging target, the results were highly impressive. The three-shot group produced a 0.6-inch group. The tM 35 did not affect the original point of impact. It is worth noting some manufacturers' units require elevation and windage adjustments to realign zero.
The tM35 utilises SWAROLIGHT technology which automatically switches on/off the device when in a "non-shooting" position, therefore saving battery life. Once in the shooting position, the unit is reactivated in 2 secs.
Swarovski has developed a product delivering a well-engineered, no-nonsense solution for those who seek a thermal solution for daylight, low-light or night shooting. There are no video recording features, live streaming, Wi-Fi, range finding, or ballistic calculators, all beguiling features contributing to the continuing thermal arms race. The designers have consciously created a practical solution that is easy to deploy and works right out of the box. Attaching the device to your scopes without concerns regarding the point of impact will be a significant selling point for the tM 35.
As you would expect from an Austrian manufactured product, the build quality is excellent. The tM 35 is compatible with SWAROVSKI OPTIK rifle scopes from the Z8i, Z6i, Z5(i), and Z3 series.
The recommended retail price of the tM 35 is £3,980.
The tMA adaptors to attach the tM 35 to a range of scopes are available in the following objective lens diameters: 24, 36, 42, 44, 50, 52, 56. They retail for £182 each.
Specification
10.9x8.7 m/100m Field of view
100 % Field of view with eyeglasses (%)
21 mm Exit pupil distance (4x magnification)
1 x Optical magnification
4 x Digital magnification
35 mm/f1.1 Objective lens
SIZE & WEIGHT
170mm Length
54mm Width
80mm Height
495g Weight
M44 x 0.75Connection thread
ENVIRONMENT & CONDITIONS -15 to +50 °C Functional temperature
-30 to +70 °C Storage temperature
IP68IP protection class
DIGITAL 60Hz Refresh rate (Hz)
AMOLED Screen type
2560 x 2048 Screen resolution (pixels)
Uncooled VOx microbolometer Sensor type
320 x 256 Sensor resolution (pixels)
12 Pixel size (µm)
2 sec Start-up time
BATTERY Li-lon 3000 mAh Battery
7 hours Battery operating time during normal/maximum operation
