TS 12" f/5 ONTC Carbon Tube Newtonian telescope - fully customizable

ONTC Newtonian Telescopes from Teleskop Service are a unique system on the market
You choose the components and the bias of your telescope and get a Newtonian without compromises for reaching your astronomical goals.

We are happy to help you with the configuration and create a complete concept tailored to measure and according to your wishes.

Please consult our sales department by phone or email
Tel.: 06835 / 923 949 -0 E-Mail: anfrage@apm-telescopes.de

The ONTC Newtonian with 303 mm aperture and 1500 mm focal length

This ONTC is a real big allrounder. The visual and photographical performance on moon and planets is impressive. If you choose a secondary mirror with 74mm diameter (short axis) you will have only 24% obstruction. You will have an image similar to a 9" APO refractor.

Astrophotographers will enjoy the moderate speed of f/5. The exposure time is short and very expensive correctors are not needed. Also the good valued 2-element correctors, like the Baader MPCC will offer good images with pinpoint stars to the edges. With suited correctors, the speed can be increased to f/3.8.

We suggest a bigger mount if you have interest in Astrophotography. The Celestron CGEM-DX, Skywatcher AZ-EQ6 or Losmandy G-11 should be the minimum. A good choose is the EQ8, if you want to mount the newtonian in an observatory.

The advantages

• optimized configuration for astrophotographic or visual use by choosing different focusers, focus positions or secondary mirrors
• Exchange of the secondary without problems - anytime
• Only selcted optics are used. Also the functionality of the optical and mechanical components are tested before shipping the ONTC.
• A complete production log is included.
• The edge of the secondary is blackened against reflexes and stray light.
• The carbon tube is made in Germany. It is manufactured in a carbon/rigid foam sandwich construction for a perfect stability at an unbeatable weight ratio
• Fantastic temperature compensating performance - barely any temperature based focus drift
• The mirror cells are manufactured in Germany, too. The telescope can be collimated completely without tools.
• One telescope, many focal distances - due to different correctors! The correctors need different focus positions above the focuser. The tube offers three positions of the main mirror cell.

Anti reflex paint for maximal contrast

We use Berger Antireflexfarbe (anti reflex paint) for the inner wall of the tubes. It blackens the wall as good as velours, but has less weight and will not attract dust. The optics will stay clean.

Choose a suitable focuser

The free choice of the focuser makes the ONTC Newtonians unique. Thus you can easily adapt your new telescope optimally to your wishes. Please do not forget to select the base for attaching the focuser to the tube. You can choose from our whole range. A few recommendations are given below:

1. TS 2" UNC Newtonian Crayford focuser - short
   Economically priced 2" Crayford focuser for observing and photography with DSLR cameras. The short focuser needs only 75 mm optical path.
2. Starlight Feather Touch 2" focuser - 20 mm draw tube travel
   2" focuser for maximal stability without compromises. In addition, the focuser is very short, together with the base, it is only 50 mm high.
3. MoonLite 2.5" Newtonian focuser with 360° rotation
   The 2.5" Moonlite focuser is especially precise and perfectly suited for heavy cameras. It is ideally suitable for long 2" correctors or for the 2.5" Wynne corrector. The focuser offers, besides 2" receptacle, also a screwed M68x1 connection.
4. Orion ACU-3S 3" Crayford focuser with M82x1 thread
   The massive 3" focuser is our recommendation for astrophotographers who want to work with a 3" Newtonian corrector. These correctors are screwed to the M82 thread of the focuser.
5. Starlight FTF3215B-A TRUE 3" Feather Touch Focuser
   THE high-end focuser for Newtonian telescopes and real 3" correctors from TeleVue, ASA or TS Optics. With very precise 3" compression ring clamping - as good as screwed adaptions.
   

Three possible focus positions above the 2" tube of the focuser

1. Astrophotography with the standard coma correctors - 65 mm above the 2" tube (STANDARD Version)
   This version is optimized for the standard correctors like the TS coma corrector, the Baader MPCC or the ASA Quattro. For visual use, you need to add the 2" extension tube.
2. Astrophotographic use with the ASA 2" Reducer/corrector - 90 mm above the 2" tube
   This position is ideal for the use of the ASA Reducer/corrector ASA2KORRR. The reducer brings the system up from f/5 to f/3.6. This version is also suited for the GPU corrector, which may not put completely into the focuser.
3. Visual use - 35 mm above 2" tube
   We recommend that version for visual use of the telescope. For this telescope line, we recommend the 58 mm secondary mirror. The 2" Paracorr VIP-2010 also works fine with this focus position.

The focus positions are calculated and achieved by changing the primary mirrors position. Of course you can also get other positions if you want, i.e. if you want to use a 3" coma corrector. The three we mentioned are the most common ones.

Further customizable parts

1. Tube color - Carbon nature or laminated
   Instead of a neat carbon glossy film, we can also offer a hard constrast white finish. Other colours are also possible, but bright colours will show more signs of wear if transported frequently.
2. Tube rings or bar directly connected to the tube
   The scope of delivery includes rings with a flat base on both sides. According to your wish, we can also attach a dovetail bar (Losmandy or Vixen style) directly to the tube. If choosing that modification, the tube gets additional fibre layers where necessary.

Delivery contents

• ONTC Newtonian Telescope WITHOUT focuser, WITHOUT base (see options)
• Tube rings or dovetail rail
• Finder base
• Dust caps for front part and focuser
• Collimation manual
• Manual for mounting the primary mirror
• Production log