Focuser extension tube M117x1 25mm for Richey Crétien Telescope
Place the 25mm RC focuser extension ring between focuser and telescope rear mounting plate to increase the distance of your focuser from the optical tube rear plate.
This forms a very rigid connection and allows you to rack your focuser inwards as much as possible, reducing flex and strain on the focuser, and improving imaging performance.
Fits 10" or larger Richey Crétien Telescopes
Extension rings can be stacked on top of each other to get different extension distances, for example:
2x 25mm rings = 50mm total
1x 25mm ring and 1x 50mm ring = 75mm total
Generally speaking, 2x 25mm and 1x 50mm rings are used to get focus with a CCD camera and filter wheel for a total of 75mm extension. With an OAG, DSLR and filter wheel, sometimes only 50mm total extension is required.
- Harrison Telescopes
- Telescope House
- Tring Astronomy Centre
- Rother Valley Optics
- F1 Telescopes
- Io Astronomy Please note: IO Astronomy voluntarily ceased trading with large unpaid debts affecting the entire UK astronomy industry. You may contact us for problems / issues with Altair or iOptron products ONLY - or try Darkframe Optics / Dave Woods. Unfortunately, we will not be able to support undeclared products bought from the ex-directors after the company ceased trading.
- Astro AS Denmark, Europe
- Robtics Netherlands
- Pierro Astro France
- SkyVision France
- Teleskop Service Ransburg Germany
North America & Canada orders:
- Land Sea & Sky (Takahashi America) USA
- Cloudbreak Optics USA
- Ontario Telescopes Canada/North America
Products can be ordered online from Altair with tracked insured shipping to anywhere in the world. For large items shipping price may need to be re-quoted.
Russia orders: Please contact.