ZWO ASI432MM Mono Solar & Lunar Camera with T2 Tilter

A global-shutter mono camera built for the Sun, with a T2 tilter included

The ZWO ASI432MM is a monochrome solar and lunar camera built on Sony's IMX432 global-shutter sensor, sold here with ZWO's T2 tilter. ZWO describes it as the upgrade of the ASI174MM, long a favorite with solar imagers: the 432 has larger 9µm pixels, a larger 1.1-inch sensor, about three times the full well and lower dark current. It records up to 120 frames per second at full resolution over USB 3.0, needs no separate power supply, and weighs 126g (4.4oz).

Key specs: Sony IMX432 global-shutter mono sensor, 1.1" (14.5 × 9.9mm) · 1.77MP (1608 × 1104) · 9µm pixels · 79% peak QE · read noise 2.9e⁻ · 97ke⁻ full well · 120 fps at full resolution (12-bit) · USB 3.0 with 256MB buffer · ST4 port · 126g

What you can capture

• The Sun in hydrogen-alpha: prominences, filaments, plage and flares through a dedicated hydrogen-alpha solar telescope or filter system.
• The Sun in white light: sunspots and granulation through a full-aperture white-light solar filter.
• Full-disk images: on a 500mm solar telescope the field is about 1.66° × 1.14°, so the whole 0.53° Sun fits with room to spare. The full disk fits on the short side of the sensor up to about 1,000mm of focal length.
• The Moon: the whole Moon in one frame on short telescopes, or quick high-resolution mosaics on longer ones.
• Transits and fast movers: the global shutter and short exposures freeze the ISS crossing the Sun or Moon without distortion.

How it works

Plug the camera into a laptop's USB 3.0 port, put it in your focuser with the included 1.25" nosepiece or thread it onto M42 adapters, and record short video clips with free software such as FireCapture or SharpCap (or ZWO's ASIStudio). Stacking software like AutoStakkert! keeps the sharpest frames and combines them. No separate power supply is needed.

The camera has a built-in high-conversion-gain mode that switches on at gain 140, which keeps about 12 stops of dynamic range while cutting read noise. That lets you use shorter exposures to freeze the seeing and still hold detail in both bright surface features and faint prominences. The sensor sits 6.5mm behind the M42 front thread (17.5mm with the 11mm T2 ring in place). The T2 tilter mounts between the camera and the telescope; its six adjustment screws set the tilt angle. A 1/4"-20 thread on the back lets you mount the camera on a photo tripod, and the ST4 port means it can also work as a guide camera.

Using it in Colorado

• Morning seeing: solar seeing is usually steadiest in the morning, before the ground heats up. The high frame rate catches the brief steady moments that turn into sharp stacks.
• Clear-sky days: Colorado's many sunny days make solar imaging an easy hobby to fit in, but never point a telescope at the Sun without proper solar filtering on the front.

What to add for the best results

• A solar filter or solar telescope (required for the Sun): for white light, a full-aperture filter such as an EclipSmart filter for 8" SCTs. For hydrogen-alpha, a dedicated solar telescope.
• A Barlow or Powermate: the Tele Vue 2.5x or 5x Powermate to reach the long focal ratios that suit the 9µm pixels for close-ups. In hydrogen-alpha, around f/25 to f/30 matches these pixels well.
• A tracking mount: a ZWO AM5N or any mount that tracks the Sun keeps the disk centered while you record.
• A laptop with USB 3.0: needed to record at full speed.

ASI432MM vs. ASI585MM vs. ASI585MC

See all ZWO planetary and all-sky cameras.

What's in the box

• ASI432MM camera
• T2 tilter (ZWO packs it in its own separate box)
• 1.25" nosepiece
• 1.25" and 2" dust covers
• USB 3.0 cable (2m)
• ST4 guide cable
• Quick guide

Solar filters, solar telescopes, Barlows and the mount are sold separately.

ZWO ASI432MM FAQ

Is the ASI432MM good for beginners?

For someone starting in solar imaging, yes. It's powered by USB, fits any 1.25" focuser, and the large pixels and full well are forgiving of exposure. You'll need proper solar filtering or a solar telescope before you start.

What is the T2 tilter for?

In hydrogen-alpha solar imaging, reflections between the sensor window and the sensor can create Newton rings, a pattern of light and dark bands. Tilting the camera very slightly with the tilter removes them. The tilter can also correct a sensor that isn't quite square to the telescope.

ASI432MM or ASI174MM?

ZWO describes the ASI432MM as the 174's successor: a 1.1" sensor with about twice the area, 9µm pixels instead of 5.86µm, a 97ke⁻ full well instead of 32ke⁻, and lower dark current. Both have a global shutter.

ASI432MM or ASI585MM for the Sun?

The ASI432MM's global shutter, larger sensor and big pixels make it the better match for hydrogen-alpha telescopes running at slow focal ratios. The ASI585MM has far more resolution and smaller pixels, so it's the better choice if you'll also image planets and lunar detail.

Can I image planets with it?

It isn't ideal. Its 9µm pixels need focal ratios of f/40 or slower for planets, which few setups reach. A small-pixel planetary camera like the ASI585MM does much better.

Can I image the Sun with it?

Yes, that's what it's built for, 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.

Specifications