ToupTek ATR294C Colour Cooled Camera

The ToupTek ATR294C is a cooled colour astronomy camera with Sony’s IMX294, a 4/3″ sensor of 11.7 megapixels with large 4.63 µm pixels and a 14-bit output.

Large pixels gather light quickly, which suits short and medium focal lengths: at 500 mm it samples at about 1.9″ per pixel, at 300 mm about 3.2″. The 23 mm diagonal needs a corrected field of that size, and 2″ or 36 mm filters. The IMX294 shows some amp glow, which dark frames remove, so take a dark library at your usual gain and temperature.

Choose the window when you order. The IR-cut version is for normal colour imaging. Clear AR-coated glass lets infrared through, for use with your own filters in front of the camera, such as a dual-band or UV/IR-cut filter.

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.