ZWO ASI120 Color Astronomy Camera User Guide
- June 5, 2024
- ZWO
Table of Contents
- ZWO ASI120 Color Astronomy Camera
- Instruction
- Camera Models and Sensor Type
- What’s in the box?
- Camera technical specifications
- QE Graph & Read Noise
- Getting to know your camera
- How to use your camera
- Clean the camera and redry desiccant
- Mechanical drawing
- Warranty
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
ZWO ASI120 Color Astronomy Camera
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 submit it on
the ZWO support site: https://support.astronomy-imaging-camera.com/
ASI120 camera is an excellent choice for those who have just started to make
astronomy photography at an affordable price. 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 ASI120 models:
| Models | Mono or Color | Interface | Sensor |
|---|
ASI120MM
(Discontinued)
| Mono| USB2.0| AR0130CS
ASI120MC
(Discontinued)
| Color| USB2.0| AR0130CS
ASI120MM-S| Mono| USB3.0| AR0130CS
ASI120MC-S| Color| USB3.0| AR0130CS
Why do I choose ASI120?
- It is mostly used for planetary imaging. It can also be used for deep sky imaging up to a certain level. This new version comes with an ST4 Auto guider Port, so you may now use it both for imaging and guiding.
- Monochrome camera sensors are capable of higher details and sensitivity than color sensors, but you need additional accessories such as filters. The post-processing is more complicated too. So the color camera is often recommended for a beginner of astrophotographers.
ZWO ASI120-S CMOS Camera follows ASI120. ASI120-S has a 3.0 USB port instead of a 2.0 port, with a faster speed! 3
What’s in the box?
ASI120MM-S and ASI120MC-S
Camera technical specifications
| Sensor | 1/3″ CMOS AR0130CS |
|---|---|
| Resolution | 1.2Mega Pixels 1280×960 |
| Pixel Size | 3.75μm |
| Max FPS at full resolution | ASI120MM-S/MC-S 60FPS(12bitADC) |
| Shutter | Rolling shutter |
| Exposure Range | 64μs-2000s |
| Read Noise | 4.0e~6.6e |
| QE peak | Almost 80% |
| ADC | 12 bit |
| Interface | USB3.0(ASI120MM-S/MC-S) |
| Adapters | 2″ / 1.25″ / M42X0.75 |
| Back focus distance | 12.5mm |
| Dimensions | 62mm |
| Weight | 100g |
| Supported OS | Windows, Linux & Mac OSX |
| Power consumption | 150ma@5V (ASI120MM-S/MC-S) |
| Working Temperature | -5°C ~45°C |
| Storage Temperature | -20°C ~60° |
| Working Relative Humidity | 20%~80% |
| Storage Relative Humidity | 20%~95% |
Notes
Our USB2.0 camera is not compatible very well with OSX & Linux. USB3.0 cameras are recommended for Mac & Linux users and are fully compatible with the USB2.0 host, for more info, please refer to “Support-manual and software” on our official website. https://astronomy-imaging-camera.com/
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. ASI120 is a very fast and sensitive USB2.0 camera. Up to 3 5 FPS under
1280 x 960 full resolution! With a peak almost 80 %%, beyo nd ICX618 and with
no FPN (Fixed pattern Noise)! Long time exposure supported up to
2000s
Mono 120 sensor
Color 120 sensor
Read noise includes pixel diode noise, circuit noise, and ADC quantization
error noise, and the lower the better. 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
External View
Protect Window
There is a D21 IR-CUT protect window in the ZWO ASI120MC-S camera to prevent the sensor from humidity and dust. The diameter is 21mm and 1.1mm thick.
Transmission chart of the UV IR-CUT filter:
ASI120MM-S comes with the D21 AR protect the window. Transmission chart of the
AR filter: 
Analog to Digital Converter (ADC)
- The ASI20 camera records in 12bit ADC. This camera also supports ROI (region of interest) shooting, and this smaller ROI has faster fps.
- Here is the maximum speed of ASI120MM-S/120MC-S running at 12bit ADC .
Resolution| 120MM-S/120MC-S (12bit)
---|---
1280X960| 60FPS
1280X720| 98FPS
1280X600| 116FPS
1280X400| 168FPS
960X960| 74FPS
1024X768| 90FPS
1024X400| 160FPS
800X800| 85FPS
800X640| 106FPS
800X48| 141FPS
640X480| 133FPS
512X440| 145FPS
512X400| 158FPS
480X320| 196FPS
320X240| 254FPS
Binning
The ASI120 camera supports software bin2 mode.
How to use your camera
You can refer to the connecting drawing blow
Color camera connecting drawing:
- 1.25” T-Mount
- 1.25”filter(optional)
Mono camera connecting drawing:
- 1.25” T-Mount
- 1.25” filter(optional)
- M42-1.25” adapter
- M42-M42（Male screw thread）
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 these dust clear.
Then attach the camera and adjust the exposure to make sure, not overexposed.
You can see an image 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 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_desi ccant.pdf
Mechanical drawing
ASI120MM-S/ASI120MC-S
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 by emailing info@zwoptical.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 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.