TS-Optics RFT 6" f/5.9 Rich-field Refractor with 2.5" R&P Focuser

The TS RFT-152 mm f/5.9 Rich Field Refractor

This refractor is a great alternative to normal achromats. The refractor offers features that are normally not found in this class.

One of the best objectives with better chromatic correction than a comparable achromat. In Japan, this refractor is even sold as a semi-apo under the name Nerius. The glasses of the 2-element objective are K9 and F4.

A 2.5" rack-and-pinion focuser with many auxiliary threads that even allows connection of the TS full-frame correctors.

The refractor is still transportable. Due to the retractable dew shield, the telescope has a transport length of only 800 mm and thus space on every back seat.

The application areas of the TS 152 mm refractor:

- Moon and planets: The image on the left was taken by Stefan Schimpf through the TS 152 mm refractor. Click on the image for maximum resolution. With suitable filters you can increase contrast and sharpness even more.

- Observation of nebulae, star clusters and galaxies: The great strength of the refractor is wide field observation. Contrast and sharpness are comparable to those of an apo in this field of application.

- Deep sky astrophotography: You can also do that with this refractor. We offer suitable field correctors. But we recommend filters that reduce chromatic aberrations, like narrowband filters or H-alpha filters.

- Nature observations: Using a 45° Amici prism will give you a correctly oriented image with comfortable viewing when looking through the eyepiece. Suitable filters are also helpful here.



The 152 mm f/5.9 objective of the TS refractor

Many amateur astronomers are surprised when they observe through this refractor for the first time. The chromatic aberration, which appears as a blue fringe around bright stars or lunar craters, is hardly visible.

The glass materials used are K9 and F4. The objective is very precisely manufactured, so that even at high magnifications the image hardly shows chromatic aberrations.

Of course, both lenses have a broadband multi-coating on the surfaces. The objective is mounted in an adjustable and temperature compensated aluminum cell.

The lens is designed as a visual lens, so it shows the best correction in the green area of the visible spectrum, where the human eye is most sensitive. Therefore, the color correction and the spherical correction will be very good for an achromatic lens.

The 2.5" focuser

A fast refractor makes no sense without a reasonably sized focuser. A 2" focuser would necessarily cause vignetting, since the relatively narrow drawtube shades the optical path.

The TS 6" refractor´s focuser has a large free internal passage with an adjustment range of 100 mm. A 1:11 dual-speed gear is available for sensitive focusing.

Via the M68 female thread you can also attach screw adaptors for astrophotography. You will find suitable adapters in the accessories section. 2" accessories are perfectly clamped on the optical axis by an effective ring clamping "almost like screwed".

Technical Information:

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

Deep Sky Photography with the TS 152mm f5.9 Refractor:

Picture at left: CED 214 von Matteo Morino (Italy)

The TS 152mm f/5.9 refractor is good for deep-sky photography, if you use filters against the chromatic aberation, like H-Alpha, R-G-B or narrow band nebula filters like O-III, S-II.

The big 3" Crayford focuser holds also heavy cameras and allows the connection of the big TS Photoline 3" field corrector TSFLAT3. So you can use CCD cameras with big sensors up to full size without vignetting in the edges.

Image information:

Telescope: TS Refractor 152 mm f/5.9
Field corrector: TS Photoline Flattener
Guiding Control: TS Off Axis Guider
Filter: Baader Swanband Nebular Filters (O-III, S-II and H-Alpha)

Solar photography with the TS 152 mm f/5.9 Refractor:

Image at left: Sun by Stéphane Langlois (France)

Image information:

Telescope: TS Refractor 152 mm f/5.9
Solar filter: Herschel wedge
Additional filter: Baader Solar Continuum
Camera: ZWO ASI1600MM


Image at left: Sun in Calcium by Stéphane Langlois (France)

Image information:

Telescope: TS Refractor 152 mm f/5.9
Solar filter: Herschel wedge
Line filter: Calcium K line filter
Camera: ZWO ASI1600MM

Three more solar photographs with the TS 152 mm f/5.9 Refractor, also by Stéphane Langlois (France):

Object: Sunspot

Imaging data:

Photographer: Stéphane Langlois (France)
Telescope: TS refractor 152 mm f/5.9
Solar filter: Baader Herschel wedge
Additional filter: Baader Solar Continuum Filter
Barlow lens: TeleVue 2x Powermate
Camera: ZWO ASI174MM


Object: Group of sunspots

Imaging data:

Photographer: Stéphane Langlois (France)
Telescope: TS refractor 152 mm f/5.9
Solar filter: Baader Herschel wedge
Additional filter: Baader Solar Continuum Filter
Barlow lens: TeleVue 2x Powermate
Camera: ZWO ASI174MM


Object: several groups of sunspots

Imaging data:

Photographer: Stéphane Langlois (France)
Telescope: TS refractor 152 mm f/5.9
Solar filter: Baader Herschel wedge
Additional filter: Baader Solar Continuum Filter
Barlow lens: TeleVue 2x Powermate
Camera: ZWO ASI174MM

Two lunar photographs with the TS 152 mm f/5.9 refractor:

Object: Moon (mosaic)

Imaging data:

Photographer: Stéphane Langlois (France)
Telescope: TS refractor 152 mm f/5.9
Filter: Baader CCD RGB-G
Barlow lens: TeleVue 2x Powermate
Camera: ZWO ASI174MM


Object: Lunar crater Copernicus

Imaging data:

Photographer: Stéphane Langlois (France)
Telescope: TS refractor 152 mm f/5.9
Filter: Baader CCD RGB-G
Barlow lens: TeleVue 2x Powermate
Camera: ZWO ASI174MM

Feedback from a customer

Our customer Darren Hennig from Canada uses this telescope for solar observation and has written a few experiences and some recommendations:

"Your item number IN152OTA is an AMAZING scope!

I say this as I got mine originally from APM (a TS152RFT last year). It is a sleeper scope for the following applications:

Solar - not only white light/continuum with Baader SA (semi-APO) with use including a Solar wedge, but also since this optical system is optimized for the Helium d-line, it is a superb SODIUM-I D scope.

Further analysis has suggested that this scope also may be optimized for the scotopic regime, near O-II/SWAN, and if so, as such could be a very versatile Magnesium-I b-line scope as well for solar!

I have bee using this unit for solar service all summer, and it is superb. I recommend the following "solar package" be offered to those with or looking at this telescope:

1) TS152RFT,
2) Herschel Solar Wedge - APM 2" or similar (Baader also fine).
3) Baader SA filter for general white light and Baader 540nm Continuum filter (optional)
4) Even better than the 540nm, a Baader SWAN band filter for Mg-I service.

This would extend the utility of this superb optical system. While unorthodox, it has countless superb applications in solar service as well!"

Thank you for sharing your experiences!

Safety informations: PDF Download