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High Precision double helical focuser for guider scope / finder scope Interface. The solution for telescopes or telephoto lenses with sluggish focusing. The Focuser has a fixed orientation - so there is no rotation of mounted cameras or eyepieces - or also the field of view with your guide star - when focusing.
Upgrade your R&P focuser by adding it to the end of the R&P focuser by using "Astromania M42X0.75 Female to M42X0.75 Female Thread Telescope Adapter - 9mm". Note: please make sure that there is M42X0.75 male thread on your R&P focuser.
Item was made by Full metal, durable. The one side of double helical focuser is M31X0.5 male thread (including a M31X0.5 female thread to M42*0.75 male thread Adapter which you can get M31X0.5 male thread or M42X0.75 male thread on this side), there are 1.25" accessory collar with male T-thread flange (M42x0.75) and Accesory collar thumbscrews on the other side that you can install StarShoot AutoGuider or 1.25" eyepiece.
Interface: 1.25 inch with M42*0.75 male thread, primary Mirror Interfaces: M31X0.5/M42X0.75
Accuracy 0.05mm; Focusing stroke: 10mm; Minimum length: 46mm; Longest length: 56mm.

Product Description

Why Choose Us

Many telescopes have a focuser which does not allow very precise focusing. Especially difficult jobs such as focusing on a planet can be a real challenge. This helical focuser elegantly overcomes the problem. You need to do nothing more than to connect it to your existing focuser.

Primary mirror interfaces: M31X0.5/M42X0.75

The one side of double helical focuser is M31X0.5 male thread, including a M31X0.5 female thread to M42*0.75 male thread Adapter which you can get M31X0.5 male thread or M42X0.75 male thread on this side.

Main Feature:

Accuracy 0.05mm
Interface: 1.25" with M42*0.75 male thread
Primary mirror interfaces: M31X0.5/M42X0.75
Focusing stroke: 10mm
Minimum length: 46mm
Longest length: 56mm
Color: black
Be made by full metal

Help To precisely Focus

The Focuser has A Fixed Orientation

A further advantage is that the accessories, like a camera, do not rotate with the focuser. Therefore the orientation of the image remains unchanged. Via the optional adapter T2i-T2i ( Asin:B01NCS8RW6 ), the focuser can be easily attached to any male T2-thread, so the connection to your telescope becomes child's play.

Setting scale - for finding the optimal focus position again

A graduated scale always shows you the focus position you have just set. Once you've found the perfect point of focus, then you just need to remember this setting on the scale - you will then always be able to find it in future. The scale itself is similar to the millimetre markings on a ruler, but each marking here moves the focuser by only around 0.05 mm.

Sharper focused Planets Via The Helical Mechanism

Once the helical focuser is attached, simply turn the focusing knob with Anti-slip texture - which you can control easily even with gloves on in winter. The rotating mechanism allows very smooth and continuous focusing, and without any play.

Adjustment Accuracy: 0.05mm

The accuracy can reach 0.05mm, 10mm focusing stroke, and more precise focusing. Will meet your need for precise focusing during photography or, lightweight and portable, it's more convenient to carry and use.

Brass Ring Design

1.25" accessory collar with brass compression insh to prevent the marring of your telescope accessories, will not scratches your expensive eyepiece or zenith mirror, safer and easier to use.

Thread For Eliminating Light

Effectively reduce stray light interference, not only improve the brightness of the image, but also effectively reduce the dark edges formed, the edge details of the image are clearer.