ZWO ASI678MM

Product Overview

The ZWO ASI678MM is a monochrome planetary camera based on Sony’s IMX678 back-illuminated CMOS sensor. It uses a 1/1.8-inch sensor with 3840 × 2160 resolution, 2 µm pixels, 12-bit ADC, USB 3.0 transfer, and a built-in 256 MB DDR3 cache.

This camera is aimed at high-resolution solar system imaging, especially when maximum sensitivity, filter-based capture, and near-infrared performance matter. Compared with the older ASI178 series, the ASI678 family improves read noise, near-infrared response, and amp-glow control while keeping a compact planetary-camera format.

Who It’s For

This is a good match if you want a monochrome camera for planetary, lunar, solar, and near-infrared imaging with filters. It is better suited than the colour ASI678MC when you want higher sensitivity, IR-pass imaging, methane-band work, or mono capture through dedicated filter sets.

Key Features & Design

• Sony IMX678 monochrome sensor: 1/1.8-inch STARVIS 2 CMOS sensor with 3840 × 2160 resolution.
• 2 µm pixels: Small pixels support fine sampling for high-resolution solar system imaging.
• Monochrome sensitivity: A strong option for filter-based planetary, lunar, solar, and near-infrared work.
• High near-infrared response: Useful with IR-pass and methane filters where longer wavelengths can improve results.
• No amp glow: Cleaner frames and easier calibration compared with glow-prone cameras.
• 256 MB DDR3 cache: Helps stabilize USB 3.0 capture and reduce frame-dropping risk.

Optical / Mechanical Design

The ASI678MM uses the IMX678 back-illuminated sensor with a 1/1.8-inch format and 8.86 mm diagonal. Its monochrome sensor avoids the Bayer matrix used in colour cameras, which makes it a better fit for filter-based imaging and applications where sensitivity is more important than one-shot-colour simplicity.

Mechanically, the camera uses ZWO’s compact planetary-camera body with USB 3.0 and ST4 connections. It has a 12.5 mm back-focus distance and supports the standard 1.25-inch/T-mount connection path shown by ZWO.

Recommended Uses

• Monochrome planetary imaging: Capture planets with luminance, RGB, IR-pass, methane, or other specialist filters.
• Lunar imaging: High-resolution monochrome Moon imaging with strong fine-detail capture.
• Solar imaging: Solar imaging when used with a safe dedicated solar setup or proper filtration.
• Near-infrared capture: IR-pass and methane-band imaging where the ASI678 family’s NIR response is useful.
• Filter-based workflows: A better fit than the MC version if you plan to use a filter wheel or manual filter changes.

Compatibility and Accessory Notes

The ASI678MM connects by USB 3.0 and includes an ST4 guide-port connection. ZWO’s connection diagram shows the camera used with a 1.25-inch T-mount connection and an optional 1.25-inch filter in the optical path.

Important Limitations

• Uncooled camera: This is not a cooled long-exposure deep-sky camera.
• Small sensor format: The 1/1.8-inch format is best for solar system and compact targets, not wide-field imaging.
• Monochrome workflow: Colour imaging requires filters and additional capture/processing steps.
• Solar safety: Never image the Sun without a proper safe solar filter or dedicated solar telescope system.

Frequently Asked Questions

Is the ASI678MM a monochrome camera?

Yes. The ASI678MM is the monochrome version of the ASI678 family.

Is this better than the ASI678MC?

It depends on the workflow. The ASI678MM is better for sensitivity and filter-based imaging. The ASI678MC is simpler for one-shot-colour capture.

Is this good for planetary imaging?

Yes. The small 2 µm pixels, USB 3.0 interface, low read-noise behaviour, no amp glow, and monochrome sensitivity make it well suited to planetary imaging.

Can it be used for deep-sky imaging?

It can be used for compact bright targets and EAA-style work, but it is mainly an uncooled solar system camera.

When should this product not be recommended?

Do not choose this camera if you want the simplest colour workflow. In that case, the ASI678MC is the better match.

Bottom Line

In short: the ASI678MM is a compact monochrome IMX678 camera for high-resolution planetary, lunar, solar, and near-infrared imaging, with small 2 µm pixels, USB 3.0 transfer, no amp glow, and stronger flexibility for filter-based capture.

Optical Diagram Reports

ZWO publishes the ASI678MC/MM quantum-efficiency response, including the colour ASI678MC curve and the monochrome ASI678MM relative response.