ASI120 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.
ASI120 Manual
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ASI120 Manual ............................................................................................................................... 1
1. Instruction ................................................................................................................................. 3
2. Camera Models and Sensor Type ............................................................................................. 4
3. What's in the box? ..................................................................................................................... 5
4. Camera technical specifications ................................................................................................ 6
5. QE Graph & Read Noise ........................................................................................................... 7
6. Getting to know your camera .................................................................................................... 9
6.1 External View ...................................................................................................................... 9
6.2 Protect Window ................................................................................................................. 11
6.3 Analog to Digital Converter (ADC) .................................................................................. 12
6.4 Binning .............................................................................................................................. 12
7. How to use your camera.......................................................................................................... 13
8. Clean the camera and redry desiccant ..................................................................................... 14
9. Mechanical drawing ................................................................................................................ 15
10. Servicing ......................................................................................................................... 16
11. Warranty ......................................................................................................................... 16
ASI120 Manual
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1. 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 has just started to make astronomy
photographing with 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/
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2. 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
color camera is often recommended for beginner of astrophotographer.
ZWO ASI120-S CMOS Camera follows ASI120. ASI120-S has 3.0 USB port instead of 2.0 port,
with faster speed!
ASI120 Manual
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3. What's in the box?
ASI120MM-S and ASI120MC-S
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4. 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 fully compatible with USB2.0 host, for more info,
please refer to “Support-manual and software” on our official website.
https://astronomy-imaging-camera.com/
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5. 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 35FPS under 1280x960 full resolution!
With a peak almost 80%, beyond ICX618 and with no FPN (Fixed pattern Noise)! Long time
exposure supported up to 2000s.
Mono 120 sensor
Color 120 sensor
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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 higher dynamic range ( longer exposure )
or set the gain higher for lower noise ( such as short exposure or lucky imaging).
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6. Getting to know your camera
6.1 External View
Mono camera
Protect and sealed window
AR coated D21*1.1mm
Color camera
Protect and sealed window
IR-CUT coated D21*1.1mm
1/4” screw
You can mount to tripod
USB2.0 IN
ST4 Guide Port
USB3.0 UBS2.0 IN
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ASI120MM-S:
AR protective window,
D21*1.1mm
ASI120MC-S:
IR-CUT protective
window, D21*.1.1mm
USB2.0
& USB3.0 IN
ST4 guide port
1/4” screw
You can mount to tripod
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6.2 Protect Window
There is a D21 IR-CUT protect window in the ZWO ASI120MC-S camera to prevent the sensor
from humidity and dust. Diameter is 21mm and 1.1mm thick.
Transmission chart of the UV IR-CUT filter:
ASI120MM-S come with the D21 AR protect window.
Transmission chart of the AR filter:
ASI120 Manual
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6.3 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
6.4 Binning
The ASI120 camera supports software bin2 mode.
ASI120 Manual
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7. How to use your camera
You can refer to the connecting drawing blow:
Color camera connecting drawing:
1. 1.25” T-Mount
2. 1.25”filter(optional)
Mono camera connecting drawing:
1. 1.25” T-Mount
2. 1.25” filter(optional)
3. M42-1.25” adapter
4. M42-M42（Male screw thread）
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8. 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 setup your telescope and point it to a bright place. A Barlow is required to
see these dusts 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 protect window.
The very small but very dark spot in the image (at left) are the shadows of the dusts 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 a very detailed instruction on our website:
https://astronomy-imaging-camera.com/manuals/How_to_clean_ASI_camera_and_redry_the_desi
ccant.pdf
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9. Mechanical drawing
ASI120MM-S/ASI120MC-S
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10. 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, dealer is responsible for the
customer service.
11. Warranty
We provide 2-year warranty for our products. We offer repair service or replacement for free if the
camera doesn’t work within 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.
Customer must pay for shipping when shipping the camera back for repair or replacement.
