GSO 1.25" / T2 eyepiece projection adapter (M42 × 0.75; SKU: CA001) (GSO Taiwan, SKU: CA001). The GSO CA001 connects an interchangeable-lens camera to a telescope with a 1.25" focuser. It supports eyepiece projection with an eyepiece inside the body, or prime-focus photography using the short adapter without an eyepiece. Connecting the camera requires a separate T2 ring matched to its lens mount.
• two-piece construction that unscrews: removing the projection body leaves a short 1.25" / T2 nosepiece
• eyepiece projection with a 1.25" barrel eyepiece whose body has an outside diameter of up to 38 mm
• option of photography without an eyepiece using the short nosepiece
• filter thread in the 1.25" standard
• support for T2 rings for different camera mounts, including Nikon F, Nikon 1, Canon EOS, Canon RF, Sony A, Sony E, Pentax K and Olympus E; the ring must match the camera
• eyepieces tested by the shop: GSO SPL 1.25" models with 4 mm, 6 mm, 9 mm, 12 mm, 20 mm and 25 mm focal lengths; remove the detachable eyecup if necessary
• selection of other eyepieces by body dimensions; focal length alone does not determine compatibility
• projection adapter: GSO CA001 with a detachable 1.25" / T2 nosepiece
• telescope-side connection: 1.25" barrel
• camera-ring-side thread: T2, M42 × 0.75
• maximum body diameter of the inserted eyepiece: 38 mm
• filter thread standard: 1.25"
• separately selected items: camera T2 ring and projection eyepiece
• warranty stated by the retailer: 2 years
The adapter combines an eyepiece projection body with a short adapter for prime-focus photography.
Eyepiece projection: the camera is attached behind the telescope eyepiece.
The eyepiece sits inside the projection body, and the adapter nosepiece is inserted into the focuser.
Prime-focus photography: the camera is connected to the telescope without an eyepiece.
The short nosepiece connects to the optical train through a 1.25" socket without using a T2 thread on the focuser.
Example of a prime-focus photography configuration.
See also: T2 rings
Guide: connecting a DSLR camera to a telescope (PDF, Polish)
