Player One Artemis-C Pro Color IMX294 Cooled Astrophotography Camera

Sony IMX294 Sensor: 11.7MP on a 23.2mm Diagonal

The Artemis-C Pro uses Sony's IMX294, a sensor based on Sony STARVIS back-illuminated pixel technology. The 4/3" format has a 19.2mm x 13mm chip and a 23.2mm diagonal; this size is very popular for deep-sky imaging.

The resolution is 11.7 megapixels (4144 x 2824) with 4.63 µm pixels and an RGGB Bayer matrix.

Dynamic Range: 65.8k e- Full Well and 1.2e Read Noise with HCG

At gain 0 the camera has 13 stops of dynamic range, a 65.8k e- full well and 7.8e readout noise.

The Artemis-C Pro features a High Conversion Gain (HCG) mode that automatically engages at a gain of 120. There it has 12.97 stops of dynamic range, a 14.5k e- full well and readout noise of 1.8e. The lowest readout noise in the specification is 1.2e.

14-bit ADC and ≈76% Peak QE for Smooth Gradations

The camera's onboard 14-bit ADC captures 16,384 levels of data, which is a higher sample resolution than 12-bit (4,096 levels).

Combined with a peak Quantum Efficiency (QE) of approximately 76%, about three in four photons at the peak wavelength are recorded.

2-Stage TEC Cooling: A 40°C Delta for Low-Noise Imaging

To combat thermal noise, the Artemis-C Pro incorporates a 2-stage thermoelectric cooling (TEC) system with a standard delta T of 40°C (±2°C) below ambient, measured at 30°C ambient with the fan at 100% and the dew heater at 10%. The recommended settings are 35°C below ambient, fan 70% and dew heater 10%, for a power consumption of 40 to 60%; the fan defaults to 70%. Dark current is 0.0015 e/s/pix at -20°C and 0.0086 e/s/pix at 0°C.

In the ASCOM window you set the target temperature, fan speed and anti-dew power. The adjustable anti-dew heater is integrated at the front of the camera, in front of the D46x2mm AR Plus multi-coated window; dew is the biggest enemy in astro imaging.

512MB DDR3 Cache: 33 FPS Data Transfer over USB 3.0

The 512 MB DDR3 cache stabilizes data transmission, effectively avoids frame dropping and greatly reduces readout noise; with it the camera no longer needs a powerful computer and still performs very well on a USB 2.0 port. Recording speed also depends on your disk, and a good solid state drive is recommended.

Over USB 3.0 the frame rates are, for the 10-bit and 16-bit columns of Player One's table: 4144×2824 at 33 / 16.5 FPS, 3840×2160 at 47 / 23.5, 2560×1440 at 97 / 52.6, 1920×1080 at 160 / 73.5, 1280×720 at 314 / 107, 1024×768 at 340 / 102, 800×600 at 429 / 127 and 640×480 at 525 / 154 FPS. Player One's text gives the 33 FPS figure for RAW8.

Mechanical Design: 4-Point Tilt and 17.5mm/12.5mm Back Focus

The 90 mm body has a rear-adjustment 4-point sensor tilt plate. A tilt plate gives a much smaller field curvature of the telescope when imaging deep-sky objects; with 4 points it is easier to know which corner needs adjusting, and a built-in high-density sponge pad blocks light from the side slits. The front has 6 M2.5 screw holes on R31.

The back focus is 17.5mm, or 12.5mm with the sensor tilt plate removed. Player One's BFL solution drawings show how to reach the usual spacing (some use 56mm to make up for filters), and the box has 17.5mm and 20mm M48 extenders and an M48-M42 adapter.

One-Shot Color Imaging with the Artemis-C Pro

As a one-shot color (OSC) camera, the Artemis-C Pro uses a Bayer matrix (RGGB) over its sensor to capture full-color images in a single exposure. It needs no filter wheel or separate red, green and blue exposures.

A monochrome camera with filters records every pixel through each filter, while the Artemis-C Pro gives a colour image from each exposure with less equipment.

Power and Connectivity: 12V Cooling Power and Type-C Ports

The rear of the camera features two Type-C ports and a 12V DC 5.5x2.1mm input. The main Type-C port handles USB 3.0 data, and with only that port connected the camera works as an uncooled camera. The 2-stage TEC needs a 12V 5A supply (not included); the cooler draws up to 3A. Player One builds in overvoltage and overcurrent protection.

Drivers, ASCOM and Getting Started

Player One provides its drivers, including the ASCOM driver, on its software download page. The manual mentions SharpCap 4, whose Sensor Analysis function lets you test the readout noise yourself.

Connect the main Type-C port and, for cooling, the 12V supply. Exposure and gain are set in the capture program; the ASCOM window holds the target temperature, fan speed and anti-dew power. Two 300s dark frames (gain 120 at -10°C and gain 0 at -20°C) are also available for you to check.