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. Just tell us what you want to do with the telescope and we make it according to your needs.
The ONTC Newtonian with 254 mm aperture and 1600 mm focal length:
This Newtonian ist he ULTIMATE telescope for lunar and planetary observation. With a suitable secondary mirror, we can force the obstruction below 20%. Optically, this ONTC Newtonian achieves the power of an 8“ APO refractor for a fraction of the price.
Of course, the Newtonian can be used for photography. Up to APS-C format, not even a corrector is needed.
The advantages of the ONTC telescopes in short:
♦ optimized configuration for astrophotographic or visual use by choosing different focusers, focus positions or secondary mirror
♦ Exchange of the secondary without problems - anytime
♦ Only selcted optics are used. Also the
functionality of the optical and mechanical components are tested before sending out the ONTC.
♦ A complete production log is included.
♦ The edge of the secondary is blackened against reflexes and false 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
♦ phantastic temperature compensating performance - barely any temperature based focus drift
♦ The mirror cellss 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.
Antireflexfarbe für maximalen Kontrast
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.
The image at left shows how dark the paint is. The diagram (image above) shows the direct comparison of
chalkboard coating / Berger anti reflex paint.
We recommend three focus positions above the 2" tube of the focuser:
1. astrophotography with the standard coma correctors - 65mm above the 2" tube (STANDARD Version)
That 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 - Art.Nr. TSV235.
2. astrophotographic use with the ASA 2" Reducer/corrector - 90mm above the 2" tube
That position is ideal for the use of the ASA Reducer/corrector ASA2KORRR. The reducer brings the system up from f/6.4 to f/4.8.
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 - the most popular focus position for this scope
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. The three we mentioned are the most common ones.
Customizable parts of the ONTC Newtonian telescopes:
If you order the instrument via our webshop, you can send us a notice in the textfield below the payment methods. There is a textfield "Informations concerning your order" where you can tell us what you want to have. The alternative is dropping us an email : firstname.lastname@example.org
The focusers are linked in the "recommended" area.
TS ACUN2 focuser - a universal 2" focuser - ideal for visual observation and astrophotography with DSLR cameras or lightweight CCD cameras. The focuser only needs 55 mm backfocus from the telescope tube.
In the price of the ONTC, the motorization of the focuser is included. The motor is already mounted.
Feather Touch FTF 2008 - an extremely low-profile and highly stable 2" focuser from world-famous manufacturer Starlight Instruments (USA).
The focuser has an extremely low profile, with only 45 mm height, important millimeters can be saved and the secondary can be kept small. Even heavy CCD cameras can be used with this focuser.
Moonlite 2,5" crayford focuser with M68 thread for extreme loads.
A nice focuser for bigger corectors like the TS 2.5" WYNNE corrector. We recommend the focuser for heavy CCD cameras with bigger sensors, where a 2" focuser would not be sufficient. The Moonlight only needs 70 mm from tube, saving valuable backfocus.
The big EV-XTn 3" Crayford focuser form Jim´s Mobile - our recommendation for big 3" correctors like the VIP-3010 Paracorr from TeleVue or the ASA 3" Wynne corrector.
The focuser is essential for cameras with large sensors, which are combined with big correctors.
Tube color - Carbon nature or laminated - included in the price:
Instead of a neat carbon gossy 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.
Rings or Rail directly connected to the tube - no change of the price:
he scope of delivery also includes rings with a flat base on both sides. According to your wish, we can also attach a dovetail plate (Losmandy or Vixen style) directly to the tube. If choosing that modification, the tube gets additional flass fibre layers where necessary.