ZWO ASI585MM Pro Cooled Mono Astronomy Camera

An affordable cooled mono camera for galaxies, nebulae and narrowband

The ZWO ASI585MM Pro is a cooled monochrome deep-sky camera built on Sony's 8.3MP IMX585 STARVIS 2 sensor. ZWO describes it as an entry-level deep-sky camera: it's for imagers who want to try LRGB and narrowband imaging on galaxies and smaller nebulae without the cost of a large sensor, and its high frame rate means it can also shoot the Moon, Sun and planets. The body is 78mm across and 73.5mm long.

Key specs: Sony IMX585 STARVIS 2 mono sensor, 1/1.2" (11.2 × 6.3mm) · 8.3MP (3840 × 2160) · 2.9µm pixels · 91% peak QE · read noise 0.7e⁻ · 38.7ke⁻ full well · two-stage cooling to 35°C below ambient · zero amp glow · 512MB DDR3 buffer · USB 3.0 plus 2-port USB 2.0 hub

What you can image

• Galaxies in LRGB: the Whirlpool, Sunflower and Black Eye Galaxies, M81 and M82, the Leo Triplet and NGC 891. On the 490mm ZWO FF70 the field is about 1.3° × 0.73° at 1.2″ per pixel; on the 612mm FF90 it's about 1.0° × 0.6° at 1.0″ per pixel.
• Narrowband nebulae: the Pacman, Bubble, Crescent and Eagle Nebulae, Thor's Helmet and the Horsehead in hydrogen-alpha, OIII and SII, even from a city backyard.
• Planetary nebulae: the Ring, Dumbbell, Owl and Cat's Eye Nebulae suit the small sensor and fine pixels.
• Wider targets: on a 250mm RedCat 51 the field grows to about 2.6° × 1.4°, enough for the Rosette, the Orion Nebula or the core of the Heart Nebula.
• The Moon, Sun and planets: 47 fps at full resolution (10-bit high-speed mode) makes it a capable lunar and planetary camera too.

How it works

A mono camera records every pixel at full sensitivity and leaves color to filters. A filter wheel in front of the camera switches between filters during the night, and software combines each filter's frames into a color image: luminance plus red, green and blue for natural color, or hydrogen-alpha, OIII and SII for narrowband. The camera connects to a computer or an ASIAIR Plus over USB 3.0 and runs its cooler from 12V (ZWO recommends 12V at 3–5A, 5.5 × 2.1mm plug, center positive, or an 11–14V lithium battery). Two USB 2.0 ports on the back power and control the filter wheel, focuser and guide camera right at the scope.

The sensor sits 17.5mm behind the camera face, including an 11mm T2 ring. Without a filter wheel, the included 21mm and 16.5mm extenders and M42-M48 adapter bring the total to the standard 55mm used by most flatteners and reducers. With a ZWO filter wheel, you remove the 11mm ring, mount the wheel directly to the camera and move the ring and extender to the telescope side, as shown in ZWO's diagram below.

Using it in Colorado

• Front Range skies: narrowband filters cut through city light, so you can shoot nebulae from Denver on any clear night, and save LRGB galaxies for darker sites like Jackson Lake State Park or the Westcliffe area.
• Moonlit nights: hydrogen-alpha is barely affected by the Moon, which turns nights most color imagers lose into productive ones.
• Big temperature swings: the cooler holds a set temperature as the night cools off, so your darks stay matched.

What to add for the best results

• A filter wheel (required for color): the ZWO EFW 5x1.25" (2025) holds LRGB plus one narrowband filter, and the EFW 8x1.25" (2025) holds a full LRGB and SHO set with a spare slot. Both plug into the camera's USB hub.
• Filters (required for color): the ZWO 7nm SHO narrowband set and the ZWO LRGB set in 1.25", or the Optolong LRGB + SHO 7nm 7-piece set. The 12.8mm sensor diagonal is easily covered by 1.25-inch filters in a wheel next to the camera.
• 12V power (required for cooling): the ZWO 12V 5A adapter at home, or a PowerTank Lithium Pro in the field.
• ASIAIR Plus: runs the camera, filter wheel, mount, guiding and focuser from your phone, including multi-filter sequences.
• ASI220MM Mini: a sensitive guide camera for a guide scope or the ZWO OAG.
• ZWO EAFN electronic focuser: refocuses automatically after filter changes and as the temperature drops.
• A telescope and mount: the ZWO FF70 + AM3N bundle is a well-matched, portable setup for this camera.

ASI585MM Pro vs. ASI585MC Pro vs. ASI533MM Pro

Want it all in one box? The ASI585MM Air pairs the same mono sensor with a built-in ASIAIR and guide sensor. See all ZWO cooled deep-sky cameras.

What's in the box

• ASI585MM Pro camera and camera bag
• 1.25" nosepiece and M42-1.25" adapter
• USB 3.0 cable (2m) and two USB 2.0 cables (0.5m)
• M42-M48 extender (16.5mm), M42 extender (21mm) and M42-M48 adapter
• Four spacers and a cover
• Quick guide

The 12V power supply, filter wheel, filters and guide camera are sold separately.

ZWO ASI585MM Pro FAQ

Is the ASI585MM Pro good for beginners?

It's one of the least expensive ways into cooled mono imaging. Mono adds a filter wheel, filters and more processing, so if this is your very first dedicated astro camera, the color ASI585MC Pro is simpler.

Mono (MM) or color (MC)?

The MC gives color images in one shot. The MM needs a filter wheel and filters but collects more signal per pixel, gives sharper detail and is the better choice for narrowband imaging from light-polluted skies.

ASI585MM Pro or ASI533MM Pro?

Both work with 1.25-inch filters. The ASI533MM Pro has a square sensor with almost twice the area, larger 3.76µm pixels, a 14-bit ADC and deeper wells, so it's better for larger nebulae. The ASI585MM Pro costs less, has finer pixels for small targets and is fast enough for planets.

Which filters and filter wheel do I need?

1.25-inch mounted filters in a 1.25-inch wheel. A common set is luminance, red, green and blue plus hydrogen-alpha, OIII and SII, which fits the 8-position EFW with a slot to spare. Many owners start with a hydrogen-alpha filter alone.

Can I image planets with it?

Yes. It runs at 47 fps at full resolution in high-speed mode, so it works for the Moon, Sun and planets. If planets are your main interest, the uncooled ASI585MM uses the same sensor at a lower price.

Does it need a computer?

It needs something to control it: a laptop with ASIStudio, SharpCap or N.I.N.A., or an ASIAIR Plus run from your phone.

Specifications