What is the benefit of the 10:1 dual-speed knobs on the Feather Touch 1.25" Focuser?
The 10:1 reduction ratio means that ten turns of the fine-focus knob equal one turn of the coarse-focus knob. This allows for extremely precise, minute adjustments, which are critical for achieving sharp focus at high magnifications, especially when imaging planets or observing fine lunar detail.
Can I use the Starlight Instruments 1.25" Feather Touch Focuser for astrophotography?
Absolutely. The focuser is designed with astrophotography in mind. The drawtube is equipped with T-threads, providing a secure, threaded connection for cameras and accessories. This, combined with the zero-image-shift Crayford mechanism and an integrated brake for heavy loads, makes it a robust imaging platform.
How does the Crayford design of the Feather Touch focuser prevent image shift?
A Crayford focuser uses a round steel shaft (roller) to press against a flat surface on the drawtube, moving it with friction. Unlike traditional rack-and-pinion focusers which have gear teeth that can introduce play or "slop," the Crayford design provides smooth, linear motion with virtually no backlash or lateral movement, keeping your target perfectly centered as you adjust focus.
Which Feather Touch travel option, 0.75" or 1.5", is right for my telescope?
The choice depends on your telescope and typical accessories. A shorter 0.75" travel is often sufficient for systems where focus is achieved close to the tube, like many Newtonians. The longer 1.5" travel provides more flexibility for refractors or telescopes that use a variety of accessories like diagonals, Barlows, or reducers, which can require more "in" or "out" focus travel.
Will the Feather Touch 1.25" focuser hold a heavy camera and filter wheel without slipping?
Yes. While the Crayford design relies on friction, the Feather Touch includes an integrated brake. This allows you to increase the tension on the drawtube or lock it in place completely, providing the necessary support to prevent slipping even with a heavy imaging train pointed near the zenith.
How will the Feather Touch 1.25" focuser improve views of Jupiter in my Dobsonian?
When observing Jupiter at high power (200x or more), standard single-speed focusers often cause the image to jump past the point of critical focus. The Feather Touch's 10:1 fine-focus knob allows you to slowly and precisely dial in the focus, letting you resolve fine details like the Cassini Division in Saturn's rings or subtle cloud bands and festoons on Jupiter that would otherwise be missed.
