Product Overview The ZWO D60 AR Protective Window is a 60 mm replacement window for ZWO's large-format cooled cameras. It is 2 mm thick, figured to 1/4 λ flatness, and carries an anti-reflective coating. It mounts directly in front of the sensor and seals the cooled sensor chamber against dust and humidity. An AR window is optically clear — it reduces surface reflections but does not block ultraviolet or infrared. That is deliberate on these bodies, and the reason is worth understanding before you order. Who It's For This is a good match if you own an ASI6200MM Pro, ASI2600MM Pro/Duo, or ASI071MC Pro and need to replace a window that is scratched, fogged, or contaminated beyond cleaning. If you run a monochrome camera behind a filter wheel, this is the window you want and the one ZWO fits: your filters already control the passband, and an IR-cut coating at the sensor would only get in the way of narrowband and infrared work. Key Features & Design 60 mm diameter, 2 mm thick: the D60 form factor, sized for ZWO's APS-C and full-frame cooled bodies Anti-reflective coating: reduces reflection losses and internal glare at the window surfaces — worth having on a large sensor where bright-star halos are most visible Optically clear: passes UV and IR straight through, leaving all wavelength control to your filter wheel 1/4 λ flatness across 60 mm: holding that figure over this aperture is why the substrate is 2 mm rather than 1.1 mm Sensor-chamber seal: on a TEC-cooled camera this window is the barrier keeping humidity away from a sensor held well below ambient Recommended Uses Replacing a scratched or contaminated window on an ASI6200MM Pro, ASI2600MM Pro/Duo, or ASI071MC Pro LRGB and narrowband monochrome imaging, where the filter wheel does the filtering and the window should stay neutral Photometry and scientific imaging, where you want no unnecessary coating shaping the passband Infrared imaging, which an IR-cut window would defeat outright Restoring the sensor-chamber seal on a cooled camera showing condensation or frosting Compatibility and Accessory Notes Cameras shipped with this window: ASI6200MM Pro, ASI2600MM Pro/Duo, and ASI071MC Pro Mono bodies take AR, colour bodies take IR-cut — with one exception. The ASI071MC Pro is a one-shot-colour camera that ZWO nonetheless fits with the AR window, so do not infer your window type from mono-versus-colour alone. Check the list Want IR-cut instead? Fit the D60 UV IR-Cut window — same diameter and thickness, different coating. That is the factory part on the ASI6200MC Pro, ASI2400MC Pro, and ASI2600MC Pro/Duo Diameter is not interchangeable: D60 fits 60 mm bodies only. ASI1600 / ASI294 / ASI183 / ASI533 take the D32; smaller planetary bodies take the D21 or D25 No installation direction: ZWO confirms the window has no preferred orientation, so the coating works either way round Replacement procedure: see ZWO's official guide, How to Replace the Camera Protective Window Mechanical part only — no electronic function, no camera communication Important Limitations This window does not cut UV or IR. ZWO states that plainly. On the ASI071MC Pro — a colour camera — that means you need a UV/IR-cut filter in your imaging train, or infrared will focus at a different point than visible light and bloat your stars This is the highest-risk window in the range to replace yourself. These are cooled, desiccated cameras — opening the sensor chamber exposes a large sensor to dust and room humidity, and any moisture sealed inside will condense the moment the TEC runs. Check your desiccant before reassembling Not a threaded filter. It is a bare optical window that only works installed inside the camera body Fits 60 mm bodies only. Check your camera against the list above before ordering Sold as a single window. No tools, gaskets, desiccant, or retaining ring included Frequently Asked Questions Which cameras use the D60 AR window? The ASI6200MM Pro, ASI2600MM Pro/Duo, and ASI071MC Pro. Why does a monochrome camera use an AR window instead of IR-cut? Because a mono camera filters in the filter wheel. An IR-cut coating at the sensor would be redundant for LRGB work and would block narrowband and infrared imaging outright. Leaving the window neutral keeps every option open. My ASI071MC Pro is a colour camera — why does it have the AR window? It is the exception in the D60 range. ZWO fits it with the AR window, so if you image with it and want IR-cut behaviour, carry a UV/IR-cut filter in your train. What is the difference between the AR window and the UV IR-cut window? The AR window is anti-reflective coated but optically clear and passes UV and IR. The UV IR-cut window blocks both. ZWO confirms the AR window does not cut UV. Does the window have to face a particular direction? No. ZWO confirms there is no specific installation direction. Why is this window 2 mm thick when the D21 and D25 are 1.1 mm? Holding 1/4 λ flatness across a 60 mm aperture takes a thicker substrate than across 21 mm. Thin glass at this diameter would not stay flat. My cooled camera is frosting up. Is the window the cause? It can be, if the seal is compromised — but exhausted desiccant is the more common culprit. Check and bake or replace the desiccant before opening the sensor chamber. Is this good for beginners? No. Replacing a window on a large cooled camera is the least forgiving job in this range. If you are not equipped to work clean and manage desiccant, have it done. Bottom Line In short: a 60 mm × 2 mm anti-reflective window at 1/4 λ flatness — the factory part for the ASI6200MM Pro, ASI2600MM Pro/Duo, and ASI071MC Pro. It stays optically neutral so your filter wheel does the filtering. It does not cut UV or IR, which matters if you run the colour ASI071MC Pro.
