ZWO ASI678MM Mono Planetary Camera

A mono 4K planetary camera that shines in the near-infrared

The ZWO ASI678MM is a monochrome planetary camera built on Sony's 8.3-megapixel IMX678 STARVIS 2 sensor. It's the camera to choose for detailed lunar work, hydrogen-alpha solar imaging, and infrared or filtered images of the planets, where a mono sensor gives sharper detail than a color one. It replaces the ASI178MM with smaller pixels, more resolution, lower read noise and no amp glow. It slides into any 1.25-inch focuser with the included nosepiece, threads onto M42 adapters and filter wheels, runs from one USB cable and weighs 126g (4.4oz).

Key specs: Sony IMX678 STARVIS 2 mono sensor, 1/1.8" (7.7 × 4.3mm) · 8.3MP (3840 × 2160) · 2µm pixels · read noise 0.6e⁻ at high gain · 11.27ke⁻ full well · 83% peak QE · 47.5 fps at full resolution · zero amp glow · USB 3.0 with 256MB buffer · 126g

What you can capture

• Jupiter and Saturn in infrared: with an 850nm IR-pass filter the image steadies in turbulent air, and an 889nm methane-band filter shows high clouds and the Great Red Spot in a different light.
• Color planets: red, green and blue videos through a filter wheel, combined for the sharpest color results.
• The Moon: high-resolution crater and rille detail. On a 400mm refractor the field is about 1.1° × 0.62°, enough for the whole Moon; on an 8-inch SCT (2032mm) it's about 13′ × 7.3′ at 0.2 arc-seconds per pixel.
• The Sun in hydrogen-alpha: prominences, filaments and surface texture through an H-alpha solar telescope, where mono sensors record every pixel of the deep-red light.
• Bright deep-sky objects: live-stacked views of bright nebulae and clusters.

How it works

Plug the camera into a laptop's USB 3.0 port with the included 2m cable, put it in your focuser with the 1.25" nosepiece, and record short video clips in free software such as FireCapture, SharpCap or ZWO's ASIStudio. AutoStakkert! keeps the sharpest frames and stacks them. No separate power supply is needed.

With 2µm pixels, aim for about f/8 to f/10 in visible light. In the infrared you can work a little lower, because longer wavelengths spread the image more. High Conversion Gain (HCG) mode switches on automatically at gain 182 and keeps read noise low at high gain. The sensor sits 12.5mm behind the front of the camera, and the ST4 port lets it double as a guide camera.

Using it in Colorado

Steady air is often what limits planetary detail along the Front Range, especially when the jet stream is overhead. Infrared light is less disturbed by turbulence, so an IR-pass filter on the ASI678MM can rescue nights when color images look soft.

What to add for the best results

• ZWO 5-position filter wheel (1.25"): holds LRGB and IR filters so you can switch without touching focus.
• ZWO LRGB filters (1.25"): for color planets and the Moon.
• An IR-pass or methane-band filter: 850nm IR-pass for steadier planets, 889nm methane for Jupiter and Saturn. Ask us about current options.
• A Barlow for shorter telescopes: the Celestron 2x X-Cel LX Barlow takes an f/5 Newtonian or refractor to about f/10.
• A solar filter (required for the Sun): a full-aperture white-light filter such as the EclipSmart filter for 8" SCTs, or a dedicated H-alpha solar telescope.

ASI678MM vs. ASI678MC vs. ASI585MC

See all ZWO planetary and all-sky cameras.

What's in the box

• ASI678MM camera
• Front cover
• Small wide-angle lens (threads onto the camera front)
• 1.25" nosepiece
• USB 3.0 cable (2m)
• ST4 guide cable
• Quick guide

Filters, filter wheel, Barlows and the telescope are sold separately.

ZWO ASI678MM FAQ

Is the ASI678MM good for beginners?

It's easy to run, since it's USB-powered and fits a 1.25" focuser. But mono planetary imaging adds a filter wheel and color processing, so most beginners start with the color ASI678MC. The ASI678MM is a great first camera for the Moon and the Sun in H-alpha, where you only need one channel.

ASI678MM or ASI678MC?

Same sensor and pixels. The MC gives color in one video. The MM is sharper per channel, has no Bayer filter in the way of near-infrared light, and is the right choice for IR-pass, methane-band and H-alpha solar work.

Which filters do I need?

For color planets, a set of LRGB filters in a filter wheel. For better results in poor seeing, add an 850nm IR-pass filter. Methane-band filters (889nm) are for advanced Jupiter and Saturn work.

Can I image the Sun with it?

Yes, but only with proper solar filtering on the telescope: a full-aperture white-light filter or a dedicated hydrogen-alpha solar telescope. Never point a telescope at the Sun without one.

Does it work as a guide camera?

Yes. It has an ST4 port and guides over USB with PHD2, though most people use a dedicated guide camera.

Specifications