Askar 135 mm f/4.5 APO Telephoto Lens - Mini Guidescope and Travel Spotting Scope

Askar FMA135 Astrograph and Triplet Apo with Flattener

The motto of Askar´s compact FMA135 is "small but mighty"! It is of course an ultra-sharp telephoto lens with fast f/4.5. Unlike the simple camera lenses on the market, the lens is also suitable for the modern, high-resolution astro cameras. The 3-element f/4.5 corrector makes the ASKAR FMA135 a professional telephoto lens for both landscape and astrophotography. The internal blackening and the elaborate multi-coating ensure high-contrast and brilliant images without reflections even under difficult lighting conditions. The use of 1.25" nebula filters is also possible, thanks to the filter thread in front of the lens.

Astrophotographic results obtained with this telescope on Astrobin:
Here you can find some astrophotographs made with this telescope model: Link to Astrobin

The FMA 135 f/4.5 as astrograph for astrophotography:
Astrophotographers will be delighted with this compact telephoto lens. Stars right up to the edge are reproduced crispy sharp when using cameras up to APS-C format. Star imaging is better than with many expensive camera lenses. With 55 mm working distance (T2 mount), you can connect all common cameras. The multi-function mount allows easy adaptation to the finder shoe of your telescope or to a piggyback camera mount via the 1/4" female thread.

The FMA 135 mm f/4.5 as a telephoto lens:
The manual APO telephoto lens is corrected up to APS-C format. From the T2 thread you have 55 mm working distance. Ideal for mirrorless system cameras, DSLR and, of course, astro cameras. The telephoto lens is so compact that it can be used hands-free. The high speed of f/4.5 allows short exposure times even under difficult lighting conditions.

The FMA 135 as compact APO refractor and mini guide scope:
The objective provides sufficient working distance for a 1.25" star diagonal and standard 1.25" eyepieces. You can make wonderful wide-field observations or simply connect an autoguider and track your telescope cleanly.

The FMA 135 as a spotting scope:
The high-contrast optics allows for exciting wildlife and landscape observations. In just a few simple steps, you can transform the telephoto lens into a compact and crisp spotting scope. You can use all standard photo tripods, the adapter is already included.

Practical tip from Teleskop-Service - how to achieve good focusing for astrophotography:
The FMA135 is equipped with a helical focuser. Although this works, it is relatively coarse. Especially with very high-resolution astro cameras, very good focusing on the star soon becomes a game of patience. The TeleFokus75 solves the problem. It offers a very precise and, above all, reproducible fine adjustment (see preview photos). When mounting the TeleFokus, we recommend wrapping the front part of the lens with some transparent, pressure-sensitive adhesive tape ("Tesa") to increase the diameter by a few millimeters. This gives the ring a better grip.

Astrophotographic results obtained with this telescope on Astrobin

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

Question:
Filter change possible for cameras with 17.5 mm flange focal distance (ToupTek, ZWO)?

Answer from Teleskop-Service:
It is possible to change the filter between the camera and lens.

Working distance of the FMA135 = 55 mm from the T2 thread

TSFSLT2 filter drawer goes directly on the camera

TST2V20 extension is placed between the drawer and the telephoto lens

Flange focal distance is now 55.5 mm - the 0.5 mm compensate for the glass path of the filter.