iOptron iAFS3 — 3-inch inline automatic focuser with iLock The iOptron iAFS3 (FA30) is the larger, 3-inch version of iOptron's inline motorised focuser. Its 68 mm clear aperture and 6 kg payload suit large-format cameras and bigger telescopes. It comes with a 2-inch visual back fitted; the focuser body itself is 3-inch.
Manufacturer model: iOptron iAFS3 (FA30) · Specifications checked against manufacturer data on 2026-11-03
iOptron iAFS3 — 3-inch inline automatic focuser with iLock
The iOptron iAFS3 (FA30) is the larger, 3-inch version of iOptron's inline motorised focuser. Its 68 mm clear aperture and 6 kg payload suit large-format cameras and bigger telescopes. It comes with a 2-inch visual back fitted; the focuser body itself is 3-inch.
iLock drive
A patented lead-worm drive passively locks the drawtube when it stops, holding focus even as the telescope's angle changes. You can focus by computer (ASCOM or INDI), with the on-board buttons, or by hand with the manual override wheel. The focuser remembers its position when powered off.
Built for imaging
A built-in temperature sensor, a built-in camera angle adjuster and two USB-C ports are included. The focuser is powered from USB 2.0. Telescope adapters are sold separately, for example M117 × 1 for GSO RC10–16, GSO 3-inch Newtonian focusers and M106 × 1 for Askar 103/120 APO. An M68 × 1 camera adapter is also available.
Specifications
Manufacturer part number
FA30
Focuser size
3-inch (2-inch visual back included)
Clear aperture
68 mm
Maximum payload
6 kg
Drawtube travel
30 mm
Focusing resolution
0.4 µm per the iAFS3 spec table (iAFS manual lists 0.6 µm for the series)
Drive
Stepper motor, lead-worm with iLock; zero backlash
iOptron iAFS3 — 3-inch inline automatic focuser with iLock The iOptron iAFS3 (FA30) is the larger, 3-inch version of iOptron's inline motorised focuser. Its 68 mm clear aperture and 6 kg payload suit large-format cameras and bigger telescopes. It comes with a 2-inch visual back fitted; the focuser body itself is 3-inch.
Manufacturer model: iOptron iAFS3 (FA30) · Specifications checked against manufacturer data on 2026-11-03
