ZWO ASI585MM USB 3.0 Monochrome Astronomy Camera

ZWO ASI585MM USB 3.0 Monochrome Astronomy Camera

Precision, Sensitivity, and Speed for Planetary and Solar Imaging

The ZWO ASI585MM pushes planetary and short-exposure imaging to new levels of clarity. Designed around Sony’s IMX585 STARVIS 2 monochrome CMOS sensor, this camera delivers exceptional sensitivity, ultra-low read noise, and remarkable tonal depth—ideal for capturing fine surface detail on Jupiter, Saturn, and the Moon, or exploring solar features in stunning monochrome contrast.

With its large 1/1.2-inch sensor format, 8.29-megapixel resolution, and 46.9 frames per second readout, the ASI585MM provides a perfect blend of field coverage and imaging precision. Whether used for planetary imaging, lunar mosaics, or Electronically Assisted Astronomy (EAA), it’s a tool that combines speed, sensitivity, and consistency in one compact, beautifully engineered package.

Optical System / Sensor Performance

At the core of the ASI585MM is Sony’s IMX585 STARVIS 2 sensor—an advanced back-illuminated CMOS chip designed for outstanding performance across visible and near-infrared wavelengths. Measuring 11.13 × 6.26 mm with a 12.84 mm diagonal, it delivers 3840 × 2160 resolution (8.29 MP total) through 2.9 µm pixels, balancing fine detail with high photon collection efficiency.

The STARVIS 2 architecture represents a leap forward in sensitivity and dynamic range. It achieves a peak quantum efficiency of 91%, capturing nearly every photon that reaches the sensor. That efficiency, paired with a large 38.7 ke⁻ full-well capacity, gives your images smooth gradients, accurate highlights, and rich shadow detail—even during extended exposures or high-contrast solar imaging.

For planetary and solar observers, this translates to crisp, clean captures with fine structure preserved across bright and dark regions alike—bringing delicate cloud bands, crater rims, and solar granulation into view with extraordinary precision.

Electronic Design & Noise Control

The ASI585MM integrates ZWO’s latest high-speed architecture for stable, low-noise operation under demanding imaging conditions. Its USB 3.0 SuperSpeed interface supports a full 5 Gb/s bandwidth, ensuring smooth frame downloads and reliable live viewing even at the maximum 46.9 FPS full-frame rate.

A 256 MB DDR3 memory buffer manages data flow between the sensor and your computer, preventing dropped frames and maintaining precise exposure timing. Whether capturing short planetary bursts or extended video sequences for lucky imaging, the result is consistent, artifact-free performance.

The camera’s High Conversion Gain (HCG) mode automatically engages at a gain of 200, reducing read noise to as low as 0.7 e⁻ while maintaining 12 stops of dynamic range. Combined with the naturally quiet STARVIS 2 sensor design, this ensures clean, high-contrast data even in low-light environments.

ZWO’s Zero Amp Glow hardware eliminates the bright corner artifacts common to older CMOS sensors, preserving a perfectly uniform background without the need for software correction or dark-frame subtraction.

Mechanical Design & Connectivity

Compact and robust, the ASI585MM features ZWO’s signature anodized aluminum housing and precision-machined body. Its 1/1.2-inch sensor format sits behind an M42 × 0.75 thread and 1.25-inch nosepiece, allowing easy integration with a wide range of telescopes, barlows, and filters.

Connectivity is simple and dependable:

• USB 3.0 port – high-speed data transfer with 5 Gb/s bandwidth

• ST-4 guide port – for direct mount control when used as an autoguider

• Power via USB – no separate external supply required

Backfocus is configurable to 6.5 mm or 17.5 mm using included spacers, ensuring straightforward adaptation to typical planetary and guiding setups.

This versatility makes the ASI585MM equally suited for planetary and lunar work, solar imaging (with a proper solar filter), or as a sensitive monochrome guide camera in deep-sky rigs.

Performance Characteristics

• Sensor: Sony IMX585 STARVIS 2 back-illuminated CMOS (monochrome)

• Sensor Format: 1/1.2" (11.13 × 6.26 mm)

• Resolution: 3840 × 2160 (8.29 MP)

• Pixel Size: 2.9 µm × 2.9 µm

• Full-Well Capacity: 38.7 ke⁻

• Peak QE: 91%

• Dynamic Range: 12 stops (HCG enabled)

• Read Noise: 0.7 e⁻ (HCG mode)

• ADC: 12-bit

• Frame Rate: 46.9 FPS (full resolution)

• Interface: USB 3.0 + ST-4 guide port

• Buffer Memory: 256 MB DDR3

• Amp Glow: None (hardware eliminated)

• Backfocus: 6.5 mm or 17.5 mm (adjustable)

• Weight: 126 g (4.4 oz)

Under the Night Sky

With its ultra-low noise and exceptional responsiveness, the ASI585MM shines under nearly any conditions. At high magnifications, it delivers exquisite planetary detail—revealing the pastel belts of Jupiter, the subtle shading of Saturn’s rings, and the sharp terminator features of the Moon.

In solar applications (with the appropriate H-alpha or white-light filtration), the ASI585MM captures fine-scale photospheric granulation and active region detail with ease. Its extended near-infrared response also makes it an excellent choice for imaging beyond the visible spectrum, providing additional contrast under less-than-perfect seeing.

For deep-sky observers using Electronically Assisted Astronomy (EAA), the high quantum efficiency and rapid readout make short-stacked exposures of galaxies and nebulae surprisingly effective, even from suburban skies.

Final Thoughts

The ZWO ASI585MM Monochrome Astronomy Camera is a compact powerhouse—refined, sensitive, and ready for any imaging task. Its STARVIS 2 sensor brings professional-grade signal response and dynamic range to planetary and short-exposure astrophotography, while its clean hardware implementation ensures dependable results every session.

For those who value precision and flexibility in a lightweight package, the ASI585MM is a superb choice: fast enough for Jupiter, quiet enough for faint nebulae, and engineered to last through years of exploration under the stars.