What is the purpose of the Starlight Instruments 2.5" M68x1 End Cap?
This end cap is designed to replace the standard compression ring on a 2.5" Feather Touch focuser. It provides a direct, secure M68x1 female threaded connection, which is essential for creating a rigid, non-flexing imaging train for astrophotography.
How does this M68x1 End Cap improve my astrophotography with a 2.5" Feather Touch focuser?
By creating a threaded connection instead of relying on a compression ring with thumbscrews, this end cap eliminates a primary source of tilt and flexure in the imaging train. This results in sharper stars across the field, especially with heavy cameras or filter wheels attached.
Is this end cap compatible with accessories other than the Teleskop Service flattener?
Yes. While it is commonly used with Teleskop Service flatteners, this end cap will work with any accessory, such as a field flattener, reducer, or off-axis guider, that features a male M68x1 thread for connection.
Why should I use a threaded end cap like the M68x1 instead of the standard 2" compression ring?
A standard compression ring holds accessories with friction and can allow for slight sagging or tilt, which degrades image quality. A threaded connection is mechanically superior, ensuring perfect alignment and rigidity that cannot be achieved with a slip-fit, compression-style adapter.
I'm trying to connect a camera with an M68 thread to my 2.5" Feather Touch focuser, is this the right part?
Yes, this is the correct adapter. If your camera, filter wheel, or other accessory has a male M68x1 thread, this end cap will allow you to attach it securely and directly to your Starlight Instruments 2.5" focuser.
Will installing the M68x1 End Cap affect my back focus when imaging with my refractor and a Teleskop Service flattener?
Yes, you must account for the physical length (thickness) of the end cap in your back focus calculations. Always measure from the shoulder of the flattener's lens element to the camera sensor, including the thickness of this adapter and any other spacers in the imaging train.
