TPO 2" Crayford Focuser for Schmidt-Cassegrain Telescopes
This Third Planet Optics Dual-Speed Linear Focuser for Schmidt-Cassegrain telescopes features the most recent innovation in focuser design to hit the astronomy market in recent years. Designed specifically to meet the heavier equipment and stability requirements of astrophotography and heavy eyepieces, the linear stability and repeatable quality of focus reached with this focuser will keep you coming back for more spectacular views of and sharper images of the night sky!
By using this 2" Crayford SCT focuser in lieu of the telescope's primary mirror, image shifting is completely eliminated. This can be a mere nuisance for casual observers, but is a serious problem for imagers.
Built with an innovative stainless steel rail system that provides extended, consistent, and linear contact with the focusing mechanism and the inside of the focuser body, even when the focuser is fully extended. This constant contact prevents slop from building up in the focuser drawtube. The result is zero flexure throughout the focus travel range, even in the worst case scenario when the focuser is parallel to the ground and carrying a heavy load such as a large CCD camera. This new linear bearing rail system also allows for the use of heavier loads up to 9 lbs.
A 10:1 fine adjustment knob gives the user superior fine-tuning ability with remarkable stability for an extended period of time. The focuser position can be locked in place with the large thumbscrew on top of the focuser for critical imaging applications. The underside of the focuser features another screw to control the focusing tension. A laser-etched measurement scale in the drawtube helps with consistently rapid focusing. This focuser also has 360º rotation ability so that it can be turned in any direction for better observing.
Attaches to the rear thread of Schmidt-Cassegrain telescopes. Custom CNC machined from aluminum and black anodized for superior aesthetics in a dependable and durable unit.
TPO 2" Crayford Focuser for Schmidt-Cassegrain Telescopes Specifications...
- Minimum focuser height without 1.25" adapter: 4.65" or 118mm.
- Maximum focuser height without 1.25" adapter: 6.65" or 169mm.
- 1.25" adapter height: 0.39"
- Tube travel length: 2"
- Focuser weight with 1.25" adapter: 25.6 oz.
- Outside diameter of drawtube: 2.32"
- Diameter of focus knob: 1.57"
- Diameter of microfocus knob: 1.06"
- Flange thread: Standard SCT female thread (2", 24 TPI)
- Measurement scale on focuser drawtube: Yes
- Rotatable: Yes
- Dust plug: 1.25" dust plug included
TPO Product Number: CF-LST
- Additional Information
SKU OS-CF-LST Manufacturer TPO Focuser Design Crayford Focuser or Mask Size 2" Drawtube Focus Control Manual Warranty 2 Year Warranty
- Included Items
- TPO 2" Crayford Focuser for Schmidt-Cassegrain Telescopes
- 1.25" Adapter
- Questions & Answers
Product QuestionsQuestion by: richard fenton on Aug 30, 2015 7:00:00 AMThis focuser can technically fit, but the original focuser will obstruct the crayford focuser knobs in some orientations and the scope will not balance on the SE mount without additional weight at the front of the scope. The focuser will also prevent the telescope from pointing near the zenith with a diagonal in place as it will hit the base of the mount. Generally a microfocuser like Starlight Xpress sells or a focus motor like JMI sells are better options on smaller SCT's on Alt-AZ mounts.Answer by: Chris Hendren on Sep 1, 2015 12:44:00 PMQuestion by: B Rose on Aug 7, 2016 3:41:00 PMWill this work on a C8 w/6.3 focal reducer for imaging with a small sensor CCD like the Atik 414?Question by: Tim Farr on Dec 25, 2016 4:26:00 PMYes, this combination will work within limits (Scope->Reducer->focuser->small/shallow back-focus CCD camera), but it will work best if the sensor of the camera is 105mm from the rear surface of the focal reducer. If you use a ruler, take 105mm (4.15"), add the depth of the male threads on the f/6.3 reducer (usually round 10-12mm), and subtract the roughly 15mm (0.6") backfocus of the Atik 414 (13mm) plus the shoulder of the nosepiece (2-3mm), you can determine the best length of the focuser and adjust the main mirror focus to put your camera in the sweet spot.Answer by: Chris Hendren (Admin) on Dec 27, 2016 2:58:00 PMwill this fit on an older 8" Celestron Ultima 2000 sct?
It has an equatorial wedge mount.
W. RipkaQuestion by: william ripka on Feb 11, 2016 9:03:00 PMIt will definitely mount to the rear-cell thread, but how well it will fit is highly dependent upon the other accessories you will be using. For reference, the focuser, at minimum extension, is 4-inches long. Take a look at how much clearance you have between your diagonal and fork, with the telescope pointed at polar-north. If you have more than 5-inches of clearance, you can easily fit this focuser. Keep in mind that any "visual-back" adaptation you are currently using will not be needed for diagonals with 1.25" or 2" nose-pieces.Answer by: Eric Blackhurst (Admin) on Feb 12, 2016 5:44:00 PM
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