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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
ZWO ASI174MM Mini Mono Guide Camera

ZWO ASI174MM Mini Mono Guide Camera

by ZWO
SKU ZWO-ASI174MINI
$399.00 - $399.00
$399.00
$399.00 - $399.00
$399.00
Price Match Policy!
  • Large 1/1.2" Sony CMOS Sensor
  • 2.4 MP Resolution (1936 x 1216)
  • 5.86µm Pixel Size
  • 77% Peak Quantum Efficiency
  • Standard 1.25" Body with ST-4 and USB 2.0 Ports
7 in stock
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • ZWO ASI174MM Mini Monochrome Astronomy Camera

    The ZWO ASI174MM Mini Mono Guide Camera pairs a large 1/1.2" Sony CMOS sensor with sensitive 5.86µm pixels to deliver an exceptionally wide field of view for autoguiding. With a resolution of 1936 x 1216, a peak QE of 77%, and low 3.5e read noise, this camera reliably detects faint guide stars even in sparse star fields. The ASI174MM Mini's 13.4mm sensor diagonal makes it the definitive choice for off-axis guiding with long focal length telescopes.

    A 1/1.2" Sensor for Dependable Off-Axis Guiding

    The primary advantage of the ASI174MM Mini is its expansive 11.34mm x 7.13mm sensor. This provides a significantly larger field of view compared to typical 1/3" guide cameras, dramatically increasing the probability of finding a suitable guide star within the pick-off prism of an Off-Axis Guider (OAG). For imagers using Schmidt-Cassegrains or Ritchey-Chrétiens, this larger sensor area is not a luxury—it is the most critical factor for reliable, frustration-free autoguiding.

    5.86µm Pixels for Stable Tracking in Average Seeing

    While many cameras pursue smaller pixels for high-resolution planetary imaging, the ASI174MM Mini's larger 5.86µm pixels are optimized for guiding stability. Larger pixels are less susceptible to the rapid, small-scale movements caused by atmospheric turbulence ("seeing"), preventing the autoguider from overcorrecting. This results in smoother tracking and rounder stars in your final image, as the camera guides on the star's centroid rather than chasing atmospheric shimmer.

    ASI174MM Mini vs. ASI120MM-S: A Guiding Comparison

    For those deciding on a dedicated guide camera, the choice often comes down to the ASI174MM Mini and the popular ASI120MM-S.

    • ASI120MM-S Advantage: The ASI120MM-S is a proven, highly capable guide camera that is more affordable, making it an excellent starting point for guiding with shorter focal length refractors and guide scopes.
    • ASI174MM Mini Advantage: The ASI174MM Mini's 1/1.2" sensor physically dwarfs the 1/3" sensor in the ASI120MM-S. This translates directly to a wider field and a much higher chance of finding guide stars with an OAG on instruments over 1000mm in focal length. Its larger 5.86µm pixels also provide more stable guiding under typical seeing conditions compared to the 3.75µm pixels of the ASI120MM-S.

    Connectivity and Design: USB 2.0 & ST-4 Port

    The ASI174MM Mini is housed in a compact 36mm x 61mm body that fits any standard 1.25" focuser or OAG. It features a dedicated ST-4 autoguiding port for direct connection to your mount and a USB 2.0 port for data transfer and power. While USB 2.0 offers a lower frame rate of 18.4 FPS at full resolution compared to USB 3.0, this is more than sufficient for the 1-5 second exposures typical in autoguiding, ensuring reliable operation without the need for a more complex interface.

  • Why choose the ASI174MM Mini over a cheaper guide camera?

    The key reason is the large 1/1.2" sensor. If you use an Off-Axis Guider (OAG), especially with a long focal length telescope like an SCT or RC, finding a suitable guide star can be difficult. The ASI174MM Mini's massive field of view makes finding a star significantly easier than with smaller-chip cameras.

    Is the ASI174MM Mini's USB 2.0 interface a disadvantage?

    Not for its primary purpose of autoguiding. Guiding exposures are typically 1-5 seconds long, meaning a high frame rate is unnecessary. The camera can still capture frames at 18.4 FPS at full resolution, which is more than enough for guiding and sufficient for basic planetary imaging. The USB 2.0 interface is reliable and requires less power and bandwidth.

    How does the ASI174MM Mini perform with an OAG on an 8" f/10 SCT?

    This is the exact scenario where the ASI174MM Mini excels. An 8" SCT has a focal length of around 2000mm, resulting in a very narrow field of view at the OAG's pick-off prism. The camera's large 13.4mm diagonal sensor maximizes the available area, giving you the best possible chance to locate a guide star without having to rotate the OAG or change your target framing.

    Can I use the ASI174MM Mini to image Jupiter or Saturn?

    Yes, it can function as a capable planetary camera. Its 5.86µm pixels and high sensitivity are well-suited for capturing details on bright planets. While it doesn't have the high frame rates of a dedicated USB 3.0 planetary camera, it can certainly produce high-quality images of the Moon, Jupiter, and Saturn.

    What does the "Electronic Rolling Shutter" mean for guiding?

    An electronic rolling shutter exposes the sensor line by line, rather than all at once. For short-exposure planetary imaging of rapidly rotating planets, this can sometimes cause subtle artifacts. However, for autoguiding with typical exposure times of 1 second or longer, it has absolutely no negative effect on performance.

    Does the ZWO ASI174MM Mini require a separate power supply?

    No. The camera is powered entirely through the USB 2.0 cable connected to your computer or an ASIAIR unit. The ST-4 port is used for sending guide pulse corrections to the mount and does not provide power.

  • Sensor 1/1.2" Sony CMOS (Monochrome)
    Pixel Array 1936 x 1216 (2.4 MP)
    Pixel Size 5.86 µm
    Sensor Dimensions 11.34 mm x 7.13 mm
    Sensor Diagonal 13.4 mm
    Peak Quantum Efficiency (QE) 77% @ 520 nm
    Readout Noise 3.5e
    Bit Depth 12-bit
    Max Frame Rate 18.4 FPS at 1936 x 1216
    Shutter Type Electronic Rolling Shutter
    Exposure Range 32 µs to 300 s
    Computer Interface USB 2.0
    Guide Port ST-4
    Telescope Connection 1.25" Nosepiece, C-Threads
    Camera Window AR Coated
    On-Camera Storage 192K byte user-accessible space
    Dimensions 36 mm x 61 mm
    Weight 0.3 lb
    Operating Temperature -5°C to 45°C
    Uncooled Yes
    ROI Support Yes

    • ZWO ASI174 Mini CMOS Camera

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    • User Manual

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  • ZWO 2-Year Limited Warranty