New T-mount adapter for C1 cameras

Main page▹Product Overview▹Astronomical cameras▹Articles	19.11.2019 \|

Small, uncooled CMOS cameras of the C1 series (as well as G1 series with CCD sensors) are traditionally equipped with CS-mount threaded adapter. This adapter allows usage of wide variety of CCTV lenses with CS-mount (and with the help of simple 5 mm thick ring also with C-mount). CS-to-1.25" barrel adapter, supplied with every camera, enables using of these cameras with virtually any telescope instead of standard 1.25" eyepiece. But 1" diameter of the CS-mount thread is a limiting factor for newly introduced C1-12000 camera with large sensor. So, new adapter, combining both CS-mount and T-mount threads, was introduced for all C1 cameras.

T-mount (also known as T-thread adapter) is defined by thread dimensions M42 × 0.75 as well as 55 mm Back focal Distance. T-thread adapter for C1 cameras does not comply to the second parameter, its BFD is only 18.5 mm. The 55 mm BFD is not required in all applications and keeping such relatively large BFD would make the adapter very long.

C1 camera with T-thread (M42 × 0.75) adapter and with CS-mount adapter (left), camera with 55 mm BFD extension tube with M48 × 0.75 and with M42 × 0.75 (right)

Still, an extension tube with male M42 × 0.75 thread on one side and the same, but female thread on the opposite side is available. This extension tube converts the C1 camera BFD to 55 mm, required by numerous focal-reducers, field-flatteners, coma-correctors and other optical elements.

As the M42 × 0.75 (T-thread) standard is more and more replaced with larger M48 × 0.75 standard, another variant of the extension tube for C1 cameras with male M42 × 0.75 thread on one side and female M48 × 0.75 thread on the opposite side with 55 mm BFD is also introduced.

Hint:

The extension tube outer diameter is exactly 2 inches (50.8 mm), so it can allow using of the C1 camera with any 2" focuser instead of 2" eyepiece.

New M42 adapter for C1 cameras also contains CS-mout compatible thread inside, so it remains compatible with all CCTV lenses and other equipment. The only exception is integrating of C1 camera with OAG. While the short (10 mm) CS-to-1.25" barrel adapter can be threaded into internal CS-mount thread, the large-diameter M42 adapter interferes with screws fixing the camera in the OAG guider port. This is why C1 variants with CS-only adapter are still supplied.

C1 camera with T-thread (M42 × 0.75) adapter is still compatible with CS-mount CCTV lenses

Warning:

The new T-mount/CS-mount adapter and classic CS-mount adapters are not user replaceable. It is necessary to specify the adapter upon order. So, if you plan to use C1 on OAG, order camera with CS-mount only.

If the adapter has to be changed later, it is necessary to send the camera to manufacturer.