What is the primary use for the ZWO T2-T2-11 11mm extender?
The ZWO T2-T2-11 is used to add a precise 11mm of spacing in an M42x0.75 threaded imaging train. It's most commonly used to help achieve the standard 55mm back focus required by many field flatteners and coma correctors, especially with ZWO cameras like the ASI1600 series.
Is this the same 11mm spacer that comes with the ZWO ASI1600MM Pro?
Yes, this is the identical 11mm female-to-female T2 spacer that is included as a stock component with all cameras in the ASI1600 series. It is the official replacement part from ZWO.
How do I use the ZWO 11mm extender to reach 55mm of back focus with an ASI1600 and a 20mm filter wheel?
The standard configuration to achieve 55mm of back focus with an ASI1600 camera and a 20mm thick ZWO filter wheel often uses this extender. The optical path is calculated as follows:
- ASI1600 Camera Sensor to Flange: 6.5mm
- ZWO EFW (Electronic Filter Wheel): 20mm
- This T2-T2 Extender: 11mm
- ZWO 16.5mm T2 Extender: 16.5mm
This combination totals 54mm, which is typically within the tolerance for most correctors. A 1mm fine-tuning spacer can be added if needed.
Are the threads on this ZWO adapter male or female?
The ZWO T2-T2-11 extender has female M42x0.75 T-threads on both sides. This allows it to connect two accessories that both have male T-threads.
Will this ZWO 11mm adapter cause vignetting?
The adapter has a clear aperture consistent with the M42 (T2) standard. It is designed to work without vignetting on sensors up to the Four Thirds format, such as the one used in the ASI1600 camera series. It may cause vignetting on full-frame (36mm x 24mm) sensors, which typically require wider M48 or M54 threads.
What material is the ZWO T2-T2-11 adapter made of?
This extender is machined from lightweight, durable aluminum and has a black anodized finish to minimize weight and prevent unwanted reflections within your optical train.