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.
Omegon
Focuser Newton Hybrid Crayford Dual Speed 2"
$ 329.00
ZWO
Electronic Automatic Focuser EAF N
$ 290.00
ZWO
Rotator CAA
$ 530.00
Omegon
2'' Newtonian Crayford focuser, dual speed 1:10
$ 169.00
Omegon
2'' SC Hybrid Crayford focuser, dual speed
$ 469.00
ZWO
Electronic Automatic Focuser EAF Pro
$ 453.00
Omegon
2'' Crayford focuser for Newtonian telescopes
$ 69.00
Omegon
2'' helical focuser
$ 89.00
Omegon
Pro 2'' Newtonian Crayford focuser, dual speed
$ 199.00
Omegon
Pro Focus Motor Estia
$ 269.00
Omegon
Alpha Crayford focuser 2" for Newtonian telescopes
$ 79.00
ZWO
Hand Controller for EAF Motor Focus
$ 81.00
PegasusAstro
FocusCube v3 Universal focusing motor
$ 337.00
PrimaLuceLab
SESTO SENSO 2 robotic focusing motor
$ 314.00
Sale price:
$ 278.20
ZWO
Helical Focuser 1.25"
$ 116.00
Celestron
Focus Motor for SC- and EdgeHD-Telescopes
$ 372.00
Omegon
Focuser Feathertouch FTF33235B-A BigRC
$ 999.00
Sale price:
$ 655.00
TS Optics
short T2 Helical Focuser & Adapter
RRP:
$ 116.00
Our price:
$ 81.00
Omegon
adapter for attaching a 2'' Crayford focuser to a Skywatcher OTA
$ 79.00
Skywatcher
2" Crayford Focuser for Explorer Newtonian Reflectors
$ 227.00
ASToptics
1.25" helical focuser (M42/T2)
$ 116.00
PegasusAstro
Rotator Falcon V2
$ 850.00
ZWO
CAA-M42 Adapter
$ 59.00
TS Optics
Focuser UNC Gen 2 Newton 2"
$ 302.00
TS Optics
Focuser R&P RC 2"
$ 302.00
Baader
Focuser Diamond Steeltrack BDS-RT 2"
$ 418.00
Baader
Focuser Diamond Steeltrack BDS-NT 2"
$ 402.00
Lacerta
Micro reduction ratio focuser retrofit
$ 117.00
Skywatcher
Rotator EvoStar 72 ED
$ 37.90
TS Optics
Focuser Monorail R86 2"
$ 291.00
Artesky
Rotator M48
$ 92.00
TS Optics
Focuser R&P 2"
$ 302.00
TS Optics
Focuser R&P 2.5"
$ 364.00
TS Optics
Focuser Monorail Newton 2"
$ 279.00
Skywatcher
Auto-Focus System for telescopes
$ 104.00
TS Optics
Focuser Deluxe 3.7"
$ 740.00
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.