ToupTek ATR294M Mono Cooled Camera

The ToupTek ATR294M is a cooled mono astronomy camera with a 4/3″ sensor of 11.9 megapixels with large 4.63 µm pixels and a 14-bit output. It’s the mono partner to the ATR294C.

Large pixels gather light quickly, which suits narrowband imaging at short and medium focal lengths: at 500 mm it samples at about 1.9″ per pixel. The 23 mm diagonal needs a corrected field of that size, and 36 mm or 2″ filters.

The sensor is sold under different names: ToupTek lists it as the IMX494, and other makers’ 294 mono cameras use the IMX492 run in its binned mode. Either way the result is the same 4.63 µm pixel.

Cooling, dew and power

Two-stage cooling takes the sensor up to 42 °C below the air temperature. It holds the set point to within 0.1 °C, so dark frames can be reused from night to night. A heater on the front window has four power settings and can be switched off in software. Cooling needs 12 V; the 12 V 3 A power supply is in the box.

Back focus and connections

Back focus is 17.5 mm from the M42 thread. Adapter rings and extension tubes are included to build out to the spacing your flattener or reducer needs, usually 55 mm. A 512 MB buffer holds each frame while it transfers, so a slow USB link doesn’t drop frames.