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
RRP:
$ 294.00
Our price:
$ 282.00
ZWO
Electronic Automatic Focuser EAF Pro
$ 459.00
Omegon
Pro Focus Motor Estia
$ 269.00
Celestron
Focus Motor for SC- and EdgeHD-Telescopes
$ 377.00
PrimaLuceLab
SESTO SENSO 3 focusing motor
$ 329.00
ZWO
Hand Controller for EAF Motor Focus
$ 82.00
PegasusAstro
FocusCube v3 Universal focusing motor
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PrimaLuceLab
SESTO SENSO 3 SC focusing motor
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Skywatcher
Auto-Focus System for telescopes
$ 105.00
PrimaLuceLab
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$ 1,040.00
PegasusAstro
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$ 247.00
iOptron
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PegasusAstro
Motor Focus Kit v2 (Universal)
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PrimaLuceLab
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$ 1,650.00
PegasusAstro
Focusing Motor FocusCube v2 for SC Telescopes (C6, C8, C9.25)
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JMI
Focus motor for Explore Scientific Configuration 1 focuser
$ 435.00
PegasusAstro
Hand Controller for FocusCube
$ 82.00
PrimaLuceLab
ESATTO 2" focuser with ARCO 2" rotator
RRP:
$ 1,970.00
Our price:
$ 1,910.00
PegasusAstro
Pulley & Belt Kit
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Meade
Zero Image Shift microfocuser
$ 494.00
Baader
SteelDrive II focusing motor with Controller<p>
$ 790.00
PegasusAstro
Motor Focus Kit v2 Celestron SCT (C11)
$ 294.00
PegasusAstro
Motor Focus Kit v2 Celestron SCT (C14)
$ 294.00
TS Optics
Focusing motor USB_Focus v3
$ 270.00
PegasusAstro
Focusing Motor FocusCube v2 for SC Telescopes (C14)
$ 435.00
PegasusAstro
Focusing Motor FocusCube v2 for SC Telescopes (C11)
$ 435.00
TeleVue
<p>Focusing motor for NP127is<p>
RRP:
$ 388.00
Our price:
$ 328.00
Rigel Systems
InFocus motor focuser for GSO OAZ Crayford focuser
RRP:
$ 353.00
Our price:
$ 282.00
PegasusAstro
Motor Focus Kit v2 Celestron SCT (C6, C8, C9.25)
$ 247.00
Rigel Systems
USBnFocus USB adapter for motor focuser
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PegasusAstro
eXternal Motor Controller
$ 223.00
Lunatico
Seletek TARSIER controller
$ 235.00
Lunatico
Seletek Limpet controller with motor kit
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Lunatico
Seletek Limpet controller with motor kit
$ 352.00
Lunatico
Seletek Limpet controller with motor kit
$ 352.00
Lunatico
Seletek Limpet controller with motor kit
$ 352.00
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.