ASI174 Manual
Revision 1.4
Aug 2021
All materials related to this publication are 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 read it thoroughly. If you have any other questions, please feel free to contact us. [email protected]
ASI174 Cameras are designed for astronomical photography.
Its excellent performance and multifunctional usage will impress you a lot!
For software installation instructions and other technical information please refer to “Support” on our official website.
https://astronomy-imaging-camera.com/
Camera Models and Sensor Type
There are 4 types of ASI174 models:
| Models | Mono or Color | Interface | Sensor |
| ASI174MM | Mono | USB2.0 | IMX174LLJ |
| ASI174MC | Color | USB2.0 | IMX174LQJ |
| ASI174MM-C | Mono | USB3.0 | IMX174LLJ |
| ASI174MC-C | Color | USB3.0 | IMX174LQJ |
Why do I choose ASI174?
Our ASI174 comes with a large sensor, large pixel size, high frame rate, and comparatively high resolution. Most importantly, with the SONY IMX174 CMOS sensor, this image sensor makes SONY Pregius Global Shutter CMOS technology available for amateurs who want to focus on high-quality Lunar, Solar, and deep-sky imaging.
Monochrome VS Color
Monochrome camera sensors are capable of higher details and sensitivity than color sensors, but you need additional accessories such as a filter wheel and filters. The post-processing is more complicated too. So the color camera is often recommended for beginners of astrophotographers.
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. However, cooling is recommended for DSO imaging when long exposures are required.
What’s in the box?
Camera technical specifications
| Sensor | IMX174LLJ / IMX174LQJ |
| Resolution | 2.3Mega Pixels 1936×1216 |
| Pixel Size | 5.86pm |
| Max FPS at full resolution | 164FPS(10bitADC) |
| Shutter | Global shutter |
| Exposure Range | 32ps-1000s |
| Read Noise | 3.5e @ 30db gain |
| QE peak | 78% |
| ADC | 12 bit/10 bit |
| Interface | USB3.0 |
| Adapters | 2″ / 1.25″ / M42X0.75 |
| Back focus distance | Uncooled 6.5mm/Cooled 6.5mm |
| Dimensions | Uncooled 62mm/Cooled 78mm |
| Weight | Uncooled 140g/Cooled 410g |
| Cooling (cooled cameras) | Regulated Two-Stage TEC |
| Delta T | 35°C-40°C below ambient |
| Cooling Power consumption | 12V at 2A Max |
| Supported OS | Windows, Linux & Mac OSX |
| Working Temperature | -5°C—45°C |
| Storage Temperature | -20°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.
Relative QE: the peak value of QE is around 78%
Read Noise includes pixel diode noise, circuit noise, and ADC quantization error noise, and the lower the better.
The Read Noise of the ASI174 cameras is extremely lower when compared with traditional CCD cameras. It is even lower when the camera is set at a higher gain.
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). 
Getting to know your camera
6.1 External View
6.2 Power consumption:
ASI174 cameras are designed to have very low power consumption which is around 300ma@5V.
You only need the USB cable to power up the camera.
6.3 Protect Window
There is an AR protect window in the ZWO ASI174MM. The diameter is 25mm, thickness is 1.1mm. 
6.4 Analog to Digital Converter (ADC)
The ASI174 camera records in 12bit ADC and 10bit ADC. You can image at a faster fps rate if you choose to use 10bit ADC (high-speed mode). This camera also supports ROI (region of interest) shooting and this smaller ROI has faster fps.
| Resolution | 12bit ADC | 10bit ADC |
| 1936×1216 | 128fps | 164fps |
| 640×480 | 309fps | 397fps |
| 320×240 | 577fps | 740fps |
6.5 Binning
The ASI174 camera supports software bin2 mode. You should use 10bit ADC. We recommend customers use software binning if they don’t care about speed.
How to use your camera
There are many adapters available for this camera for connecting to your scope or lens. Some are included with the camera and others you can order from our site:
Clean the camera and redry desiccant
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. A Barlow is required to see this dust clear. Then attach the camera and adjust the exposure to make sure not over exposed. 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 protected 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 them is to 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/How_to_clean_ASI_camera_and_redry_the_desiccant.pdf
Mechanical drawing
Servicing
For software upgrades please refer to “Support-manual and software” on our official website. https://astronomy-imaging-camera.com/
For repairs and consultation: https://support.astronomy-imaging-camera.com/
For customers who bought the camera from your local dealer, the dealer is responsible for the customer service.
Warranty
We provide a 2-year warranty for our products, we will offer repair service for free or replace for free if the camera doesn’t work within the warranty period.
After the warranty period, we will 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.
