ZWO ASI2600MM P25 Monochrome Cooled Astronomy Camera – 2025 Edition

The Camera That Defined an Era, Refined for the Next

ZWO’s ASI2600 series changed the way astrophotographers approached the night sky. With its blend of APS-C format, deep cooling, zero amp glow, and whisper-low read noise, the ASI2600 quickly became the “sweet spot” camera for imagers who wanted professional performance in a package they could trust night after night.

Now ZWO has taken that winning design and polished it further with the ASI2600MM P25 (2025 edition). Building on the beloved IMX571 monochrome sensor, the P25 refines the electronics, strengthens the cooling system, doubles the onboard memory buffer, and improves throughput for smoother, faster, more reliable imaging sessions. It is the natural evolution of a modern classic.

The Sony IMX571: Still the Gold Standard

At the heart of the ASI2600MM P25 lies Sony’s IMX571 APS-C format back-illuminated CMOS sensor. This 26.1-megapixel monochrome chip (6248 × 4176 resolution) delivers 3.76-micron pixels across a generous 23.5 × 15.7 mm active area, a size that works beautifully with refractors in the 400–1000 mm range as well as many reflectors and compound telescopes.

With a quantum efficiency peaking around 91%, the IMX571 captures more photons per second than older CCDs ever could, making faint details in nebulae and galaxies accessible even from suburban skies. Pair it with narrowband filters and the camera becomes a tool for science-grade deep-sky imaging in the hands of an amateur astronomer.

Monochrome Imaging: Maximum Flexibility

A monochrome sensor doesn’t lock you into a factory color filter array. Instead, it puts you in control. With the ASI2600MM P25, you choose what the camera sees. Run a luminance filter under dark skies for sharp structural detail. Rotate through red, green, and blue filters to build natural-color images. Or reach into the invisible with hydrogen-alpha, oxygen-III, and sulfur-II filters to reveal structures that no one’s eyes can see.

This flexibility is why serious imagers overwhelmingly choose monochrome cameras: they give you the sharpest data, the cleanest colors, and the freedom to adapt to any target.

Cooling and Thermal Stability

Deep-sky astrophotography is a game of long exposures. Heat is the enemy. The ASI2600MM P25 tackles that problem with a two-stage thermoelectric cooler capable of driving the sensor 30–35 °C below ambient temperature. Even on warm summer nights, this keeps dark current negligible and allows for exposures measured in minutes instead of seconds.

ZWO has also reworked the internal heat sink design for the P25, creating more even temperature distribution across long imaging runs. Calibration frames (bias, darks, flats) line up consistently, giving you a stable, repeatable imaging workflow.

And because dew is the quiet saboteur of many imaging sessions, the ASI2600MM P25 integrates a low-power polyimide window heater that prevents condensation from forming on the protective optical window. Together, these features ensure your camera is ready for marathon sessions under the stars.

Zero Amp Glow, Low Noise, and True 16-Bit Depth

The ASI2600MM series earned its reputation in part because of what you don’t see in the data. Thanks to ZWO’s design, the P25 is completely free of amp glow, an artifact that plagued earlier CMOS cameras. Its read noise drops as low as 1.0e at high gain, and even at lower gain settings remains impressively quiet.

The sensor also runs a true 16-bit ADC, which means your images capture subtle tonal gradations from the darkest shadows to the brightest star cores. Star colors look natural, nebula transitions are smooth, and faint details hold their structure during processing.

Smarter, Faster Electronics

The big internal change with the P25 upgrade lies in its redesigned electronics. ZWO has doubled the onboard memory buffer to 512 MB DDR3, which helps smooth out data transfer during large full-frame downloads or when running multiple devices through the camera’s hub.

Frame rates see a small but welcome boost, up to 14 fps in ROI modes, making the camera more versatile for those who like to experiment with planetary, lunar, or EAA work in addition to long-exposure astrophotography. These refinements may seem subtle, but they add up to a camera that feels more responsive and dependable in practice.

Designed for Seamless Integration

Despite its professional performance, the ASI2600MM P25 remains refreshingly simple to integrate. Power comes through a standard 12V DC 5.5 × 2.1 mm port, and ZWO recommends a supply rated for at least 3 amps to handle cooling, electronics, and the dew heater without strain.

A dedicated USB 3.0 Type-B port carries the heavy load of high-resolution image data, ensuring fast downloads even when working with dozens of full-frame subs. To make life easier in the field, ZWO includes a built-in two-port USB 2.0 hub right on the camera body. Plug in your filter wheel, guide camera, or electronic focuser, and suddenly your cabling is simplified to a single run back to your control computer.

ZWO also includes an assortment of adapters, spacers, and a tilt plate to help you achieve the standard 55 mm optical backfocus required by most flatteners and reducers. In short, the ASI2600MM P25 doesn’t fight your imaging train — it enhances it.

Imaging Tip

If you are upgrading from a one-shot color camera, the jump to the ASI2600MM P25 will feel transformative. The combination of fine monochrome resolution, narrowband flexibility, and deep cooling unlocks the true potential of your optics. Use moonlit nights for RGB color data, and save dark, transparent nights for luminance or narrowband. Over time, you’ll assemble image sets with the kind of depth and subtlety that rival observatory-class results.

For refractors in the 400–800 mm range, this camera frames nebulae beautifully, while still resolving small planetary nebulae and galaxy cores with elegance. On larger reflectors, it becomes a high-resolution tool for galaxies and globular clusters. Few cameras are this adaptable.

Final Thoughts

The ZWO ASI2600MM P25 doesn’t try to be a radical departure from what came before. Instead, it perfects a proven design. By refining the cooling system, doubling the buffer, improving electronics, and maintaining the beloved IMX571 sensor at its core, ZWO has created a camera that feels even more polished, stable, and inspiring to use.

For imagers who demand the cleanest data, the most flexible workflow, and the kind of performance that makes every clear night feel like an opportunity rather than a battle, the ASI2600MM P25 is ready to become the new heart of your astrophotography system.

Please note that the camera needs to be connected to an external 11-15v power supply to implement the cooling function. We recommend you use 12V@3A DC adapter (5.5*2.1mm, center pole positive) or lithium battery with 11-15V to power the camera.

This is the one you will need.