ZWO's Widest Guide Camera with USB 3.0 Functionality

The ZWO ASI174MM Monochrome Astronomy Camera is designed for high-performance planetary, solar, and lunar imaging. Featuring the Sony IMX174 global shutter CMOS sensor, this camera combines a large sensor size, high quantum efficiency, and excellent speed, making it one of the most versatile monochrome cameras available in ZWO’s lineup. Whether you’re capturing full-disk solar images or guiding at long focal lengths, the ASI174MM delivers precision and clarity.

With a resolution of 1936 x 1216 and a 5.86 μm pixel size, the ASI174MM provides detailed images with excellent light sensitivity. Its large 1/1.2" sensor and 13.4mm diagonal make it easy to capture the full disk of the Sun or Moon with many common solar telescopes — eliminating the need for image mosaicking. Capable of up to 164 FPS, the ASI174MM is ideal for freezing moments of steady seeing during high-speed planetary or solar imaging.

 

Sony IMX174 Sensor – big benefits

At the core of the ASI174MM is the Sony Pregius IMX174 sensor. With a peak quantum efficiency of approximately 78%, low read noise (~3.5e), and a global shutter, it delivers sharp, high-contrast images free from motion distortion and fixed pattern noise. This makes the ASI174MM especially effective for fast-moving targets and high-magnification imaging.

Thanks to its large sensor and high sensitivity, the ASI174MM is also a strong performer as a guide camera — especially in off-axis guiding setups with long focal length telescopes. The global shutter helps ensure clean, undistorted star tracking even at high frame rates, while the wide field of view makes it easy to locate guide stars in sparsely populated fields.

 

Camera Performance

With a high frame rate, large sensor, global shutter, and strong low-light performance, the ASI174MM is ideal for a wide range of imaging applications. It provides a balanced combination of speed, sensitivity, and resolution that is especially valuable for capturing fine detail in solar, lunar, and planetary targets, while also doubling as a reliable and accurate guide camera.

The performance graph for the ZWO ASI174MM shows that at gain 0, the camera delivers its maximum full well capacity of approximately 32,000e⁻ and a dynamic range of around 12 stops, making it ideal for deep-sky imaging where preserving both highlights and faint detail is important. As gain increases, read noise decreases significantly—dropping from about 5.5e⁻ at gain 0 to 3.5e⁻ at gain 30, and reaching approximately 2e⁻ by gain 100. However, this comes at the cost of full well capacity, which declines sharply, resulting in a reduced dynamic range of about 7 to 8 stops at higher gain levels. For planetary imaging, where short exposures and high frame rates are used, higher gain settings help reduce noise and improve detail. In contrast, deep-sky imaging benefits from lower gain to maximise dynamic range. For guiding, moderate gain settings (around gain 30–50) provide a good balance between sensitivity and dynamic range, enabling reliable star detection and accurate corrections.

The camera achieves a peak QE of approximately 78% around the 500–550 nm range, corresponding to the green portion of the visible spectrum. This high QE ensures that a significant portion of incoming photons is converted into electronic signals, enhancing the camera's ability to detect faint celestial objects and utilise dimmer guide stars for more accurate tracking during long exposure sessions. 

 

Full Specifications

Type	Monochrome
Sensor Type	IMX174
Sensor Size	11.3 mm × 7.1 mm (1/1.2")
Pixel Size	5.86 μm
Read Noise	~3.5e
Resolution	2.3 MP (1936x1216)
Max Framerate	164 FPS
Zero Amp Glow?	Yes
Delta T	N/A
Memory Buffer	256GB DDR3
Shutter	Global Shutter
QE Peak	~78%
Full Well	32,000e⁻
Back Focus	6.5mm / 17.5mm
ADC	12-bit
Exposure Range	32 μs – 1000 s
USB	3.0
Adapter	M42 X 0.75
Weight	126 g

 

Mechanical Drawing

 

Recommended Accessories

	ZWO 850 IR 1.25-inch Filter Add a IR-Pass filter to enhances contrast in planetary imaging (great for Mars, Jupiter, Moon).
	ZWO ASIAIR Plus - 256GB Model Control your new astronomy camera with the ZWO ASIAIR Plus. This device enables you to control, guide, filter control and power your camera without using a computer. Perfect for streamlining and cord management!
	ZWO ADC Atmospheric Dispersion Corrector Add an ADC which helps correct colour fringing caused by atmospheric dispersion (especially for low-altitude planets).
	ZWO 7 Position 2-inch Electronic Filter Wheel Add 7 of your favourite filters into an electronic filter wheel to swap between them automatically. Suitable for 2" threaded filters.

	ZWO 850 IR 1.25-inch Filter Add a IR-Pass filter to enhances contrast in planetary imaging (great for Mars, Jupiter, Moon).
	ZWO ASIAIR Plus - 256GB Model Control your new astronomy camera with the ZWO ASIAIR Plus. This device enables you to control, guide, filter control and power your camera without using a computer. Perfect for streamlining and cord management!
	ZWO ADC Atmospheric Dispersion Corrector Add an ADC which helps correct colour fringing caused by atmospheric dispersion (especially for low-altitude planets).
	ZWO 7 Position 2-inch Electronic Filter Wheel Add 7 of your favourite filters into an electronic filter wheel to swap between them automatically. Suitable for 2" threaded filters.

 

Connection Method

 

 

About ZWO Optical

Astrophotography has never been easier.

Established in 2011, ZWO Optical is a fast-growing global astroimaging camera powerhouse based in Suzhou China. They focus on building and innovating ground-breaking CMOS cameras such as the iconic ZWO ASI120MM Monochrome CMOS camera (the first-ever planetary CMOS camera to beat a CCD in the early 2010s). ZWO continues to pioneer new astrophotography technology with revolutionary features to capture exceptional quality of images of space that will last you a lifetime. Today, ZWO cameras are recognised by every passionate astrophotographer and are available in over 25 countries internationally.

Product Code: ZWO-ASI174MM