TS-Optics 102 mm f/11 SD – FPL53 APO Apochromat with 2.5″ RAP focuser


The TS 102 mm f11 SDP Apo offers excellent chromatic aberration correction by pairing FPL53 with additional special glass

♦ Very good correction of chromatic aberrations by a 2-element APO lens with FPL53 from Ohara and an additional special glass

♦ Very good correction also in the violet color range, where faster SD-Apos give in a bit

♦ Even at 250-300x sharpness is maintained

♦ Adjustable lens mount

♦ Improved 2.5″ rack and pinion RAP focuser with photo thread, 2″ and 1.25″ adaption

♦ Retractable dew shield for better transport and optimal protection against stray light

♦ Deluxe finder holder for adapting finder telescopes

♦ Binoviewers can be used without path compensation

♦ CNC tube rings and EQ5 style dovetail bar included

♦ With only 4.6 kg the ED is well supported by mounts like the Skywatcher EQ5

♦ Each TS Apo is individually tested before shipping (optics, mechanics, cosmetics), a checklist is attached.

Only 1 left in stock (can be backordered)


TS-Optics 102 mm f/11 SDP APO Refractor

A refractor with a 2-element objective and a correction like a triplet apochromat, this is realized by the TS 102 mm f/11 SDP Apo. The objective consists of two special glasses, including FPL53 from Ohara (Japan). The apochromat not only holds good chromatic correction in the spectral range of 480-656 nm, but due to the relaxed focal ratio of f/11 and the additional special glass, the correction is still very good even in the violet and short wavelength blue light. This makes the apo a fine telescope for observation and photography, if you want to get the optimal performance out of 102 mm aperture.

Binocular observation: If you remove the rear tube end piece, the working distance increases from 150 mm to 270 mm, with the draw tube retracted. This also allows you to combine binoviewers and a 2″ star diagonal and observe without path compensation.

The advantage of a 102 mm f/11 ED refractor:
In direct comparison to an achromatic refractor of similar size, the TS 102ED offers better color fidelity with excellent contrast. 102 mm aperture collect 63% more light than a telescope with 80 mm aperture. This makes the 102ED also an exciting telescope for deep sky observation. The relaxed focal ratio of f/11 and the high-quality 2.5″ RAP focuser allow very accurate focusing. The maximum magnification range of approx. 250x can already be achieved with good inexpensive eyepieces. The 102 mm ED is an exciting alternative for all amateur astronomers who are looking for a flexible and portable telescope for all observation areas of amateur astronomy.


Aperture: 102 mm
Focal length: 1122 mm
Focal ratio: f/11
Objective: Dublet ED objective (FPL51 with additional special glass) in adjustable cell
Resolving power: 1.15″
Limiting magnitude visually: 11m8
Dew shield diameter: 121 mm outside, 110 mm inside
Tube length with retracted dew shield: 1000 mm
Tube diameter: 105 mm
Tube extension: 120 mm long, M85x1 thread
Tube weight: 4.6 kg


Use the TS Optics 102 with your choice of MountFor visual, we recommend a Saxon EQ3 w/Steel Tripod and pier extension (adequate), a Kson EQ4 with a pier extension (very good), or  HEQ5 or EQ6 Pro with relevant Pier if your looking at automating. 

What’s this about being especially suitable for binoviewers?

Binoviewers are remarkable devices that look like a binocular, but attach into your telescope, allowing you to use both eyes (stereo) for viewing.  The TS Optics 102 was designed from the ground up to be highly compatible with binoviewers.  This means that usually, you will NOT need to use an optical corrector, or barlow to make use of them, allowing improved viewing quality, a greater range of compatible eyepieces, and a wider view that would be otherwise possible.  They provide a stunning experience with this particular telescope.

Customer Reviews

***** (5) – Many thanks to Marcel at AstroDog for the extremely prompt service and for making this telescope available. At F11, this was purchased for visual observation of planets, moon and brighter deep space objects, and has proven to be a very well made and a very capable performer. A great instrument that does indeed keep things sharp and clean at high magnification. A joy to use!  – Geoffrey

We recommend the Celestron #93691 Stereo Binocular Viewer, coupled with some lightweight eyepieces to get started with binoviewing.

Questions?  Call us on 1300 ASTRODOG or just use the form!

e.g. "Peter"

Additional information

Weight 7 kg
Dimensions 130 × 40 × 40 cm