The ASI294MC Pro is the first camera in the world equipped with the latest Sony sensor IMX294CJK. This is one of the top-selling cameras from ZWO. Looking at the specifications and comparing it to the relatively low price, it is easy to see why. Some of the highlights include:

• back-illuminated sensor – improving sensitivity and reducing noise
• 4/3” format with 4.63 um pixel size – ideal for many types of telescopes
• 14-bit ADC– giving high dynamic range of 13 stops
• An impressive 7ke- full well capacity- helping to reduce the issue of, for example, saturated stars.

On top of this, it also has a very high QE-value with a peak of over 75%. If you are looking for a small-format OSC camera for astrophotography, you can’t go wrong with the ASI294MC Pro.

IMX294CJK

Sony 10.71M-Effective Pixel Color CMOS Image Sensor (official description from Sony site), with a diagonal of 21.63mm (4/3 format). ZWO has refined the sensor and remolded it to increase the diagonal to 23.2mm with approximately 11.71M-Effective pixels (4/3 format).

High-Sensitivity Type 4/3 CMOS Image Sensor that Supports 4K for Astronomic Cameras and Industrial Applications

The IMX294CJK sensor is the first in-house image sensor for astronomic cameras to adopt the 4/3 format and provides the necessary number of pixels for true 4k output at 120 frames per second (w/ ADC 10-bit output mode, the ASI294MC can run up to 25fps at 4k format when used with USB 3.0). In addition, the use of larger-sized pixels achieves SNR1s of 0.14 lx* which is very close to the value of the ASI224 (0.13 lx*).

Exceptional low-illumination performance

Exceptional low-illumination performance of SNR1s :0.14lx is realized by use of a large-size optical system and by expanding the area per pixel to 4.63µm. This makes the IMX294CJK ideal for astronomic camera market applications that require low-illumination performance.

14-bit ADC and 13stops dynamic range

ASI294 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.

The ASI294MC Pro has a 14bit ADC unit, allowing it to achieve 13 stops of dynamic range. This is an excellent characteristic for deep sky imaging, which inherently needs high dynamic range. At 13 stops, the ASI294MC has even more dynamic range than the ASI1600.

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.

The ASI294MC provides a great full well capacity of 63700e-, which is 3 times higher than the capacity of the highly regarded ASI1600. Even bright stars won’t saturate under long exposures. This also means that this camera can achieve higher SNR (signal to noise ratio) with just one single exposure.

HCG Mode

HCG (high conversion gain) mode, which reduces read noise to even lower levels at higher gain without loss to dynamic range, is automatically enabled when the gain setting is 120 or higher. Read noise will drop under 2e-, while dynamic range will remain at 13 stops.

Unlocked Bin1 Mode

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.

Unlocked Bin1: 12bit ADC,2.3um pixel size,47megapixels,8288*5644 resolution, 14k full well capacity.

Bin2: 14bit ADC,4.6um pixel size,11.7megapixels,4144*2822 resolution, 66k full well capacity.

You can learn more differences between unlocked Bin1 and Bin2 modes by comparing the performance charts.

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.

ASI294MC Pro has the same mechanics as ASI1600 Pro. There are four screws that seal the sensor chamber. Our camera design has been extensively tested and is very stable. Even when used in higher humidity environments, ASI294MC Pro will still work well 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%.

The IMX294 sensor is a BSI (backside illuminated type) sensor, which has very high QE (quantum efficiency, which we estimate is over 75% peak).

ASI294MM Pro vs ASI1600MM Pro

Dark Current

The dark current of the ASI294 is a bit lower than the ASI1600 at same temperature, based on our test results. Dark frame sample @ Highest dynamic range settings, 300s, -10°C, bin1. Please check the dark frame to make sure you fully know the performance. ASI294MC Pro Dark Frame

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 Delta T 35? is tested at 30? ambient temperature. It might get down when the cooling system is working for a long time. Also, as the ambient temperature falls, the Delta T would also decrease. 

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!

Please notice that the camera needs to be connected to an external 11-15v power supply to implement the cooling function. We recommend you use 12V@3A DC adapter (5.5*2.1mm, center pole positive) or lithium battery with 11-15V to power the camera. If you don’t have one, please click this link to buy a 12V power adapter. There are 4 different standards for different countries, please make sure you selected the correct adapter when placing the order.