ZWO ASI294MM Mono

ASI294MM is a back-illuminated, 4/3” format,14-bit ADC camera with 4.63um pixels. It is the mono version of ASI294MC, one of the top selling cameras from ZWO. It has an impressive 66ke- full well capacity and 4144*2822 big resolution.

Not only does it have a very high QE value with a peak at about 90%, but feature an ultra-low readout noise of 1.2e. If you are seeking for a small-format mono camera for astrophotography, then ASI294MM Pro gonna be your ideal choice.

14-bit ADC and 13stops dynamic range

ASI294MM has very similar parameters as its color version. Both have the 14bit ADC and a high dynamic range of 13 stops, which is even higher than that of ASI1600MM camera.

Backlit Sensor

The back-illuminated CMOS sensor improves sensitivity and noise reduction – the key factors to enhancing image quality, while radically realigning their fundamental pixel structure from front-illumination to back-illumination. It has retained the advantages of CMOS image sensors such as low power consumption and high-speed operation.

With a conventional front-illumination structure, the metal wiring and transistors on the surface of the silicon substrate that form the sensor’s light-sensitive area (photo-diode) impede photon gathering carried out by the on-chip lens. A back-illuminated structure minimizes the degradation of sensitivity to optical angle response, while also increasing the amount of light that enters each pixel due to the lack of obstacles such as metal wiring and transistors that have been moved to the reverse of the silicon substrate.

Camera Performance

Large well depth capacity, low read-out noise and high dynamic range.

The full well capacity of 66387e of ASI294MM is near the top of all ASI DSO cameras. It ensures a very high dynamic range up to 13stops that will greatly reduce overexposure probability and help gain richer color gradation.

When the gain value is 120, the magical HCG high gain mode is turned on, the readout noise will be largely decreased (as low as 1.2e), and the dynamic range is basically unchanged.

QE Value

As ZWO’s latest BSI (backside illuminated type) mono camera, ASI294MM has very high QE performance, not only higher than its color version, but even ASI1600MM. It is estimated that the QE peak value is about 90%.

ASI294MM Pro vs ASI1600MM Pro

USB3.0 & 256M DDR3 Memory

The ASI294MM Pro is equipped with a USB 3.0 transmission interface and a built-in 256MB(2Gb) DDR3 cache to ensure stable and secure data transmission. Under long exposure, it effectively avoids frame dropping and greatly reduces the glow effect caused by slow reading speed.

Notice: For the possible amp glow that shows on your images, please refer to this tutorial: “What is Amp-glow and how do I manage it? “