ASI294 Manual
All material in this publication is subject to change without notice and its copyright totally belongs to Suzhou ZWO CO., LTD.
Instruction
Congratulations and thank you for buying one of our ASI Cameras! This manual will give you a brief introduction to your ASI camera. Please take the time to read it thoroughly and if you have any other questions, please feel free to contact us at [email protected].
Welcome to join ZWO FB and User Forum below!
Facebook: https://www.facebook.com/ZwoDesignAstronomyCameras
User Forum: https://bbs.astronomy-imaging-camera.com/
ASI294 Camera is specifically designed for astronomical photography. It is not only suitable for DSO imaging but also for Planetary imaging. You will be impressed by its superior performance and wide use!
| Models | Mono or Color | Regulated TEC Cooling | Sensor |
| ASI294MC | Color | No | SONY IMX294 CMOS |
| ASI294MM | Mono | No | SONY IMX294 CMOS |
| ASI294MC Pro | Color | Yes | SONY IMX294 CMOS |
| ASI294MM Pro | Mono | Yes | SONY IMX492 CMOS |
Which camera to choose?
Normally, mono camera sensors are with higher sensitivity, better at high-demand shooting tasks.
But extra accessories will be needed, such as filter wheel and filters, etc. Post-processing of images is also complicated, thus we recommend the color cameras to fresh users.
TEC cooling will help to reduce dark current noise for long exposures. For short exposures, such as under one second, the dark current noise is very low. So cameras without TEC cooling are normally recommended for planetary imaging. For DSO imaging, we recommend you use a cooled camera since long exposures are required.
For software installation instructions and other technical information, please refer to our official website https://astronomy-imaging-camera.com/
What’s in the box?


Camera technical specifications
| Sensor | SONY 1MX294 CMOS SONY IMX492 CMOS (AS1294MM Pro) |
| Diagonal | 23.2mm |
| Resolution | 11.7 Mega Pixels 4144’2822 |
| Pixel Size | 4.63pm |
| Image area | 19.2mm*I3mm |
| Max FPS at full resolution | I9FPS |
| Shutter | Rolling shutter |
| Exposure Range | 32ps-2000s |
| Read Noise | 1.2-7.3e (OSC) I.2-8e (mono) |
| QE p eak | About 75% (OSC) About 90% (mono) |
| Full well | 63.7k e (color) 66.4k e (mono) |
| ADC | 14 bit |
| DDR3 buffer | 256MB |
| Interface | USB3.0/USB2.0 |
| Adapters | M42*0.75 |
| Protect window | AR window |
| Dimensions | 62mm Diameter (uncooled) 78mm Diameter (cooled) |
| Weight | 140g (uncooked) 410g (cooled) |
| Back Focus Distance | 6.5mm |
| Cooling: | Regulated Two-Stage TEC |
| Delta T | 35°C -40°C below ambient |
| Cooling Power consumption | 12V at 3A Max |
| Supported OS | Windows, Linux & Mac OSX |
| Working Temperature | -5°C-45°C |
| Storage Temperature | -10°C-60°C |
| Working Relative Humidity | 20%-80% |
| Storage Relative Humidity | 20%-95% |
QE Graph & Read Noise
QE and Read noise are the most important parts to measure the performance of a camera.
Higher QE and Lower read noise are needed to improve the SNR of an image.


Read noise includes pixel diode noise, circuit noise, and ADC quantization error noise, and the lower the better.
As you can see, the Readout Noise of the ASI294 camera is extremely low when compared with traditional CCD cameras. In addition, it is with Built-in HCG mode, which can effectively reduce read noise at high gain and keep the same wide dynamic range for this camera as at low gain. When the gain is 120, the HCG mode will be automatically turned on. Additionally, the read noise is as low as 1.2e while the dynamic range can still be close to 14bit.
Depending on your target, you can set the gain lower for a higher dynamic range (longer exposure) or set the gain higher for lower noise (such as short exposure or lucky imaging).
ASI294MC 
ASI294MM
ASI294MM Pro – Unlocked Bin1 Mode

Getting to know your camera
External View
Left: ASI294MM/MC
Right: ASI294MM/MC Pro

You can order the holder ring from us or our dealer to mount the cooled camera to the tripod.
There is a 1/4″ screw under the holder

Power consumption
ASI294 camera is with low power consumption, max at 1.85W (power supplied by USB).
Recommended power supply for cooling: 12V@5A DC adapter (5.5×2.1mm, center pole positive).
Also suitable: lithium battery with 11-15V.
Here is the ASI294 cooling efficiency graph.

DDR Buffer
ASI294 Pro camera includes a 256MB(2Gb) DDR3 memory buffer to help improve data transfer reliability. Additionally, the use of a memory buffer minimizes amp-glow, which is caused by the slow transfer speeds when the camera is used with a USB 2.0 port.
Cooling system
The ASI294 Pro camera has a robust, regulated cooling system, which means that the camera sensor can be kept at the desired temperature throughout your imaging session. The super-low readout noise, combined with efficient cooling and adjustable gain setting, allows you to do short or lucky DSO imaging, unlike the traditional CCD cameras which need very long exposures for each frame. However, keep in mind that cooling won’t help with very short exposures such as less than 100ms. The lowest temperature that can be set is -35℃~-40℃ below ambient. Here is a dark current test result of the ASI294 Pro sensor at various temperatures.

Back focus distance
When an 11mm T2 Extender is removed from the camera, the back focus length is reduced to 6.5mm.
Protect Window
There is a protective window in front of the ASI294 camera sensor, with 32mm diameter and 2mm thickness.
ASI294 uses the AR coated filter.

Analog to Digital Converter (ADC)
The ASI294 camera can record in 14bit ADC and 12bit ADC. You can image at a faster fps rate if you choose to use 12bit ADC (high-speed mode). This camera also supports ROI (region of interest) shooting, and a smaller ROI range supports faster fps.
Here is the maximum speed of ASI294 running at 12bit ADC or 14bit ADC.
Bin 2 Mode
| USB3.0 | ||
| Resolution | 12Bit ADC | 14Bit ADC |
| 4144*2822 | 19fps | 16.3fps |
| 4096*2160 | 24.7fps | 21.1fps |
| 3840*2160 | 24.7fps | 21.1fps |
| 1920*1080 | 47.9fps | 41fps |
| 1280*720 | 69.8fps | 59.7fps |
| 640*480 | 100.5fps | 86fps |
| 320*240 | 179.3fps | 153.4fps |
Unlocked Bin 1 Mode
| USB3.0 | ||
| Resolution | 12Bit ADC | 14Bit ADC |
| 8288*5644 | 4.6fps | 5.7fps |
| 7680*4800 | 5.3fps | 6.7fps |
| 6400*4096 | 6.2fps | 7.8fps |
| 4096*2160 | 11.4fps | 14.3fps |
| 3840*2160 | 11.4fps | 14.3fps |
| 1920*1080 | 21.2fps | 26.6fps |
| 1280*720 | 29.8fps | 37.4fps |
| 640*480 | 40.8fps | 51.1fps |
| 320*240 | 64.6fps | 80.9fps |
Binning
The ASI294 camera supports software bin2, bin3, and bin4 modes.
How to use your camera
There are many adapters available for this camera for connecting to your scope, DSLR lens, and other astronomical equipment. Some are included with the camera and others you can order from our site: https://astronomy-imaging-camera.com/product-category/accessories
Uncooled camera connecting drawing:
- 1.25” T-Mount
- 1.25”filter(optional)
Cooled color camera connecting drawing:
- M43-T2 adapter
- EOS-T2 adapter
- 2” Filter (optional)
- 1.25” T-Mount
- 1.25” Filter (optional)
- M42-1.25” Filter (optional)
- T2 extender 11mm

Cooled Mono camera connecting drawing:

| 1. M43-T2 adapter 2. EOS-T2 adapter 3. 2” Filter (optional) 4. 1.25” T-Mount 5. 1.25” Filter (optional) 6. M42-1.25” Filter (optional) | 7. T2 extender 11mm 8. M42-M48 extender 16.5mm 9. T2-T2 adapter 10. EFW mini 11. EOS adapter for EFW |
For the detailed connecting drawing of cooled cameras, please read this tutorial:
https://astronomy-imaging-camera.com/tutorials/best-back-focus-length-solutions-55mm.html
Cleaning
The camera comes with an AR protect window, which can protect the sensor from dust and humidity. Should you need to clean the sensor, it’s better to do so during the daytime. To see the dust, you just need to set up your telescope and point it to a bright place. One Barlow lens is required to see this dust clear. Then attach the camera and adjust the exposure to make sure, not overexposed. You can see an image like below if it’s dirty.
The big dim spot on the image (at right) are the shadows of dust on the protective window.
The very small but very dark spot in the image (at left) are the shadows of the dust on the sensor.
The suggested way to clean dust on the protective windows is try to blow them away with a manual air pump. To clean the dust on the sensor you will need to open the camera chamber.
We have very detailed instructions on our website: https://astronomy-imaging-camera.com/manuals/

Mechanical drawing
ASI294MM/MC
ASI294MM/MC Pro
Servicing
For software upgrades please refer to “Support-manual and software” on our official website.
https://astronomy-imaging-camera.com/
Repairs and servicing are available at the support page of the ZWO site: https://support.astronomy-imaging-camera.com/
For customers who bought the camera from your local dealer, a dealer is responsible for the customer service.
Warranty
We provide a 2-year warranty for our products. We offer repair service or replacement for free if the camera doesn’t work within the warranty period.
After the warranty period, we continue to provide repair support and service on a charged basis. This warranty does not apply to damage that occurred as a result of abuse or misuse or caused by a fall or any other transportation failures after purchase.
The customer must pay for shipping when shipping the camera back for repair or replacement.


















