In every telescope, the focuser is attached close to the focal point of the light-gathering optic. Eyepieces can be connected to the focuser. For astrophotography, a camera is attached to the focuser, and the focuser serves to focus the camera.
ZWO
Electronic Automatic Focuser EAF N
$ 276.00
ZWO
Electronic Automatic Focuser EAF Pro
$ 449.00
Omegon
Pro Focus Motor Estia
$ 269.00
ZWO
Hand Controller for EAF Motor Focus
$ 80.00
Celestron
Focus Motor for SC- and EdgeHD-Telescopes
$ 345.00
PrimaLuceLab
SESTO SENSO 3 focusing motor
$ 322.00
PegasusAstro
FocusCube v3 Universal focusing motor
$ 333.00
iOptron
Electronic Automatic Focuser iEAF
$ 299.00
PrimaLuceLab
SESTO SENSO 3 SC focusing motor
$ 345.00
Baader
SteelDrive II focusing motor with Controller<p>
$ 770.00
Skywatcher
Auto-Focus System for telescopes
$ 103.00
Baader
Metal magnetic ring for Homing Sensor Steeldrive II
$ 85.00
PegasusAstro
Motor Focus Kit v2 (Universal)
$ 150.00
PegasusAstro
Dual Motor Focus Controller DMFC
$ 241.00
JMI
Focus motor for Explore Scientific Configuration 1 focuser
$ 437.00
PegasusAstro
Hand Controller for FocusCube
$ 80.00
PegasusAstro
Focusing Motor FocusCube v2 for SC Telescopes (C6, C8, C9.25)
$ 214.00
PegasusAstro
Motor Focus Kit v2 Celestron SCT (C11)
$ 287.00
PegasusAstro
Motor Focus Kit v2 Celestron SCT (C14)
$ 287.00
PegasusAstro
Focusing Motor FocusCube v2 for SC Telescopes (C11)
$ 214.00
PegasusAstro
Focusing Motor FocusCube v2 for SC Telescopes (C14)
$ 214.00
TeleVue
<p>Focusing motor for NP127is<p>
RRP:
$ 379.00
Our price:
$ 328.00
Rigel Systems
InFocus motor focuser for GSO OAZ Crayford focuser
RRP:
$ 345.00
Our price:
$ 276.00
PegasusAstro
Motor Focus Kit v2 Celestron SCT (C6, C8, C9.25)
$ 241.00
Rigel Systems
USBnFocus USB adapter for motor focuser
$ 138.00
PrimaLuceLab
Focusing motor SESTO SENSO 3 LS
$ 402.00
PegasusAstro
eXternal Motor Controller
$ 218.00
Lunatico
Seletek TARSIER controller
$ 230.00
Lunatico
Seletek Limpet controller with motor kit
$ 344.00
Lunatico
Seletek Limpet controller with motor kit
$ 344.00
Lunatico
Seletek Limpet controller with motor kit
$ 344.00
Lunatico
Seletek Limpet controller with motor kit
$ 344.00
Lunatico
Seletek Limpet controller with motor kit
$ 344.00
PegasusAstro
Pulley & Belt Kit
$ 34.90
Lacerta
stand-alone motorised focuser
$ 610.00
TS Optics
Focusing motor with control for Crayford focuser
$ 277.00
Skywatcher Crayford focuser on a Newtonian telescopeEyepieces and cameras are usually equipped with connector sockets. Two diameters have been established for the connector socket, which are specified in inches: 1.25" = 31.8mm and 2" = 50.8mm.
The focuser consists of two interlocking and sliding tubes, so that the eyepiece can be moved into focus using a small wheel. Not only eyepieces can be attached to focusers, but cameras as well.
Precise focusing is especially important for astrophotography. Therefore, high-quality focusers with reduction adjustment should be used for this application. For astrophotography, many focusers also have a connector thread, so that the camera is screwed into place instead of being be plugged in.
Simple focusers are adjusted using a rack and pinion mechanism. In the higher quality versions, this rack and pinion is angled and made of brass. Instead of a rack and pinion, the adjustment can also be made by exerting pressure on a special surface. Such focusers are usually referred to as Crayford focusers.
Helical focusers work in a completely different way. Here, the adjustment is made by rotating the inner barrel using a longitudinal screw (helix). One advantage is that a rotary knob is not necessary, which can get in the way, for example, of a guidescope.
As a rule, focusers can also be motorised. This improves focusing accuracy and also allows the remote operation of the telescope.