Brand: ZWO

ZWO ASI294MM Pro USB3.0 Cooled Monochrome Astronomy Camera (ASI294MM-P)


Brand: ZWO

ZWO ASI294MM Pro USB3.0 Cooled Monochrome Astronomy Camera (ASI294MM-P)


$1,280.00 USD

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$1,280.00 USD

Easy Payment Options with .

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Product Description

Important: For the following imaging camera models, please use a separate 12V power supply rather than the power hub in the ASIAIR Pro as the hub cannot provide enough amperage to power the camera's TEC coolers: ASI6200, ASI2600, ASI2400, ASI533, ASI294, ASI071MC

By popular demand, we now introduce the ASI294MM Pro. This is the monochrome version of the ASI294MC Pro – one of the top selling cameras from ZWO.

Some of the highlights include:

  • Back-illuminated sensor – improving sensitivity and reducing noise
  • 4/3” format with 4.64 um pixel size – ideal for many types of telescopes
  • 14-bit ADC – giving a high dynamic range
  • An impressive 66ke- full well capacity- helping to reduce the issue of for example saturated stars
  • 4144*2822 high resolution – with the Bin1-mode the camera can operate at a resolution of 8288*5644 and pixel size of 2.3 um.

On top of this, not only does it have a very high QE-value with a peak at about 90%, but also feature an ultra-low readout noise of 1.2e. If you are looking for a small-format monochrome camera for astrophotography, you can’t go wrong with the ASI294MM Pro.

14-bit ADC and 13 stops dynamic range

ASI294MM Pro 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 the well-known and celebrated ASI1600MM Pro camera.

Backlit Sensor

Sony’s back-illuminated CMOS image sensor improves the sensitivity and noise reduction – the key factors to enhancing image quality. It does this by radically realigning the fundamental pixel structure from front-illumination to back-illumination, while still retaining 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 the 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. These components have been moved to the back-side 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 Pro is near the top of all ASI DSO cameras. It ensures a very high dynamic range of up to 13 stops that will greatly reduce the issue of overexposed images and also help to collect richer color information.

When the gain value is set to 120, the HCG high gain mode is turned on. We’re not saying it’s magic…but we’d like to think it is pretty close. With the HCG-mode turned on, the readout noise is greatly reduced, and the dynamic range is basically unchanged.

Unlocked Bin1 Mode (also see photo)

Yet another perk of the ASI294MM Pro is that the pixel size is switchable – you can switch between unlocked Bin1 mode and Bin2 mode anytime in your astrophotography software. The unlocked Bin1 mode changes the pixel size into 2.3um and increases resolution to 8288×5644. The ability to unlock bin1-mode was a popular request from our customers. Of course we listened to you and worked quickly to make it possible.

Remember that using Bin1-mode will decrease the full well capacity compared to the standard bin2-mode.


  • Bin1: 12bit ADC, 2.3um pixel size, 47 megapixels, 8288*5644 resolution, 14k full well capacity.
  • Bin2: 14bit ADC, 4.6um pixel size, 11.7 megapixels, 4144*2822 resolution, 66k full well capacity.

If the sampling accuracy you get with the 2.3um pixel size falls within a reasonable range, then the unlocked Bin1 mode will help you get more object details. However, you will lose dynamic range and ADC bit depth. Also the image files you get at Bin1 will probably be around 4 times bigger than Bin2.

So in the end the unlocked Bin1 mode is double-edged, you may choose to use it or not depending on the specific circumstances during your imaging sessions.

Reliable Mechanics

There are four screws on the camera that seal the sensor chamber. This kind of design has been extensively tested and is very stable and secure. Even when used in higher humidity environments, ASI294MM Pro will still work fine without dew problems.

QE Value

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

Two-Stage TEC Cooling: Ultra-Low Dark Current

Thanks to the two stage TEC cooling, ASI294MM Pro can lower the CMOS sensor temperature to more than 35 degrees Celsius below ambient temperature, which can greatly reduce dark current generation and sensor noise even during extended exposure times.

The unique dark current suppression technology can further reduce dark current noise. When it’s cooled to -20℃, the current noise can be as low as 0.0022e/s/pix, which is completely negligible!

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.


Resolution 4144 x 2822 (Bin 2) 8288x5644 (Unlocked Bin 1)
Format 4/3"
Pixel Size 4144 x 2822 (Bin 2) 8288x5644 (Unlocked Bin 1)
Diagonal 23.1 mm
ADC 14 bit
Dynamic Range 13 stops
Full Well 66 ke
QE Peak About 90%
Readout Noise 1.2 - 7.3e
Max fps 16.3
Back Focus Distance 6.5mm/17.5mm

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