TS-Optics 70 mm f/6.78 ED 4-Element Flatfield Refractor Telescope

TS-Optics 70 mm f/6.78 SD travel refractor for observation and astrophotography

The SD apo is an ideal travel telescope for all photographers. The telescope is very well corrected by the built-in corrector on the axis and in the field. In addition, the SD apo also offers a decent visual performance. Magnifications of up to approx. 150x are well handled by the lens, the chromatic error is significantly reduced. We recommend the telescope for all photographers who are looking for a portable, inexpensive and yet well corrected refractor for photography and observation. Since the corrector is built into the tube, the costly adapter battle is no longer necessary. Simply focus and you are automatically at the optimal distance.

The connection of accessories:

The TSED70Q has a very comfortable working distance of 135 mm from the 2" receptacle, so you can use 2" star diagonal mirrors and eyepieces and you can focus with ease.

To connect a camera, we recommend the adapter TSFA240, this adapter has 40 mm length and a T2 thread on the camera side. With this adapter you can connect all common DSLR, mirrorless system or astro cameras. In addition, the focuser has an M54x0.75 female thread for screwed adapters.

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin

Technical Information

Teleskop-Service has collected a lot of helpful information about refractors and provided it in English as a PDF file: refractors.pdf

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin



Test report of the TSED70Q

We have tested the TSED70Q extensively and are very satisfied with the optical performance.

The telescope is also convincing on the outside: The apo is an absolute lightweight with 2.8 kg, but at the same time makes a very solid impression.
The focuser is decisive for every clean shot. The TSED70Q is equipped with a 2.5" rack and pinion focuser. Here nothing wobbles. The focus position remained absolutely stable after the obligatory cooling time.

The built-in 2-element corrector sits in the tube. So the often annoying exact achieving of a working distance is no longer necessary. You only have to come into focus. This can be done, for example, using the 21 mm T2, and 16.5 mm T2-M48 adapter included in the scope of delivery of cooled ZWO cameras.

IC2118, the Witch Head Nebula, served as the object. The camera used was a ZWO ASI071 at Gain 90. Due to the short focal length of the TSED70Q and the relatively large sensor of the camera we got a field large enough for this extended object.

Despite the relatively short exposure time of 2.5 h and the weak brightness of this object (Mag 13), we could already resolve many details. Also the color in the structures already shows up well.

Simon Großlercher & Stefan Muckenhuber

Question:
How can I adjust the smoothness and shifting of the focuser?

Answer from Teleskop-Service:
The shifting is determined by the fit of the sliding pieces at the top of the focuser. This cannot be changed. The smoothness can be adjusted as follows:
- Slightly loosen the two chrome-plated Allen screws in the middle.
- Tighten the four countersunk grub screws to the left and right of the Allen screws clockwise as little as possible (perhaps only 1/8 of a turn at first).
- Tighten the chrome-plated screws again.
- You may need to repeat this several times in both directions until you find the optimal point. It is important that all four grub screws are adjusted in the same direction and by the same amount.

Technical Information

Teleskop-Service has collected a lot of helpful information about refractors and provided it in English as a PDF file: refractors.pdf

Safety informations: PDF Download