ASI120MM (mono)


ASI120 is a very fast and sensitive USB2.0 camera. Up to 30FPS under 1280X960 full resolution! With a peak QE of 75%, beyond ICX618 and with no FPN(Fixed pattern Noise)! Long time exposure supported up to 1000s.

Free World Wide Shipping for cameras and accessories orders above 300 $.
SKU: ASI120MM Categories: ,

Product Description

Astrophotography Performance

ASI120 is a very fast and sensitive USB2.0 camera. Up to 30FPS under 1280X960 full resolution! With a peak QE of 75%, beyond ICX618 and with no FPN(Fixed pattern Noise)! Long time exposure supported up to 1000s.

120 Gain RN DR FW vs gain

Absolute QE Curve:


What’s in the box?

–ZWO ASI120MC Color 1.2 Mega Pixel Astronomy Camera
–150° Lens Adapter for use as an all-sky camera
–M42-1.25″ nose-piece
–2 m long USB cable
–2 m long ST4 guider cable
–Quick guide


  • The lens can be screwed in too far, result in a scratch on the protect window! Please adjust it very slowly! Don’t turn it beyond the focus at infinity!
  • Full resolution function of the ASI120 requires full 480mbs USB communication!
  • Mac OSX may not compatible well. Neither Windows though virtual machine. Windows though Bootcamp is recommended. Or use our ASI120S USB3.0 Cameras which runs well under Mac OSX.


ASI120 cameras have several reviews at world mos popular astronomy magazines. You can read them in PDF documents:


Camera technical details

Sensor: 1/3″ CMOS AR0130CS(Color) / MT9M034(mono)
Resolution: 1.2Mega Pixels 1280×960
Pixel Size: 3.75µm
Exposure Range: 64µs-1000s
ROI: Supported
Interface: USB2.0
Bit rate: 12bit output(12bit ADC)
Adaptor: 2″ / 1.25″ / M42X0.75
Dimension: φ62mm X 28mm
Weight: 100g
Working Temperature: -5°C—45°C
Storage Temperature: -20°C—60°C
Working Relative Humidity: 20%—80%
Storage Relative Humidity: 20%—95%

Supported resolution

Binning 1×1:


Binning 2×2:

Before first usage of this product read manuals and install correct drivers and software.


  • Fast Shipping(amount ≧ 299USD) for free
  • Fast Shipping(amount < 299USD) : $20.00
  • Free Shipping(amount < 299USD) (Air Mail, 3-4 weeks) (Free)


  1. Fast Shipping: we will choose DHL, UPS, TNT, EMS etc to deliver it. Usually you will get your package in one week. We provide free fast shipping for order ≧ $299 or charge extra $20 for order < $299.
  2. Free Shipping: we will ship via DGM or China Post Registered Air Mail. It usually costs 2-3 weeks to reach US or Europe and costs 3-4 weeks to reach far places.
  3. Customers from Brazil and Chile should leave a message to provide your CPF or CNPJ as your custom needs it.
  4. Customers from Russia need to provide the name of your company.

Tracking site:


China air mail:


  • The price list on our website is USD without tax.
  • Please note that buyers areliable to pay tax involved, such as Import tax, VAT , customs handling fee, etc. The additional fees may be collected at time of delivery by courier.
  • For best local service we advise customers buy our cameras form local dealers.

Warranty and Return Policy

  • We provide 2-year warranty for our products, we will offer the repair service for free or replace for free if the camera doesn’t work within 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.
  • Customer must pay for shipping when shipping the camera back for repair or replacement
  • If you get a faulty camera, please contact us as soon as possible though email: Please describe the problem in detail and we will do our best to help you solve the problem. Most instances perceived problems are simply bad driver install or software configuration.
  • For customers who bought the camera from our dealer, dealer is responsible for the customer service for you.

Do you have uestion, answer or comment? Post here!

  1. :

    I want to know if the ASI120MM USB 2.0 is now supplied with the glass window to prevent dust to settle on the CMOS sensor. In the photo is not showed this glass window

    • Sam Wen


      yes, ASI120MM come with a AR coated window

  2. :

    I could read that the read noise of the ASI 120MM using the low speed mode is about 6e-.

    I would like to know which is the read noise of this camera using the high speed mode.

    Thanks in advance.

  3. :

    Hi Sam,
    I read on the forum you work on the cooling mod for ASI120MM.
    I’ve got one and I’m interesting about that…
    Some news ?

    • Sam Wen


      there is addtional cooler, but it may cause dew problem, so we need more time to consider release it or not

  4. :

    i’d like to know, how many dead pixels to consider the camera defective ? My ASI120MM has one from the first day…

    • Sam Wen


      sensor factory usually guarantee there are less than 3

  5. :

    I use the Innovation Foresight ONAG which utilizes IR >750 mm for guiding. Are these wavelengths blocked by the glass window? Can it be removed?

    • Sam Wen


      no, the protect window is AR coated instead of IR-CUT

  6. :

    As I’ve just ordered an ASI1600MM-Cool I have updated the drivers ( on my imaging laptop (Win 10). However this has stopped my ASI120MM (USB2) guide camera from working with the native support in PHD2. About half the time I cannot connect to the camera and the other half PHD will connect to the camera but complains that it cannot get an image in 30sec. Before the driver update I had no problems.

    The camera is showing in device manager and PHD2 can connect and get images from the camera using the latest ASCOM driver (

    Any ideas why the native support no longer works or how I can fix it?

  7. :

    Hi Sam.

    I read that ASI120MM has compatibility issues with Mac. Could you please specify what type of issues are they?.


    • Sam Wen


      such like no images or broken frames
      USB3.0 cameras are recommended

  8. :

    Hi Sam.
    I have problems in order to connect my USB2 ASI120MM camera to an USB3 port. When I connect an USB 2 Mouse to an USB 3 port the mouse funcions perfectly but it seems the camera driver does not allow the ASI120MM if connected via an USB2 cable to an USB3 port.
    This happens on my laptop as my desktop PC and the capture or guiding SW do not see it. Is it possible to redesign the driver to restore the USB compatibility?
    Thanks in avance. M.

    • Sean Wang


      we try ASI120 using USB2 cable plugin USB3 port, and works well. I think maybe you should try another cable.

  9. :

    Can the ASI120MM be used with an active USB extension cable of 16 to 32 feet long? If so, which brand/model extension cable is best?
    Thank you.

    • Sean Wang


      Yes, It can works in that length. I don’t know but you can asking the seller which one is best.

  10. :

    “we try ASI120 using USB2 cable plugin USB3 port, and works well. I think maybe you should try another cable.”

    And I did it even before your advice but nothing changed.
    But since last week everything seems to be ok, using both USB2 cables to USB3 port on both pc’s … so, what the heck did happen ????

    • Sean Wang


      I don’t know, computer always have some strange issue with no reason…

  11. :

    2 people have asked if the window is IR cut or AR coated and they were told AR coated. The product description says IR cut, which is correct?

    “What’s in the box?
    –ZWO ASI120MM Monochrome 1.2 Mega Pixel Astronomy Camera
    –150° Lens Adapter for use as an all-sky camera
    –M42-1.25″ nosepiece
    –1.25″ IR-cut window
    –2 m long USB cable
    –2 m long ST4 guider cable
    –Driver & Extra Software CD”

    • Sam Wen


      sorry, this should be one mistake
      we will correct it soon

  12. :

    Hi, I lost my nosepiece for the ZWO ASI120MM camera! Can you provide a replacement? Thanks!

  13. :

    Hi, How much mA of current asi120mm Would need?

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