TS Universal Large 2.5-Inch Field Flattener for Refractors from f/5 to f/9
TS Optics Field Flattener and Corrector for f/5 - f/9 Refractors - 61.5mm free aperture
Exceptional field correction for all refractors combined with large camera sensorsAdvantages of the TS 2.5" flattener
Many refractor correction lenses are not able to illuminate even medium-sized sensors without vignetting or other aberrations. For this reason, Teleskop-Service has designed a 2" corrector with very good characteristics and which has proven high-level results with many systems, however the bigger 2.5" flattener by TS offers the same characteristics but is able to deal with even bigger sensors. Compared with 2" (or smaller T2 systems), this flattener can illuminate full-format (24x36mm) sensors even at fast refractors without vignetting.
The corrector is suitable for the following refractors (and possibly many others):
All systems with a focuser bigger than 2". For all relevant makes, we offer adaptions: Starlight Instruments Feather Touch, Astro Physics, William Optics, Astro Professional and TS Apos. The photographic speed may be between f/5 and f/9.
The 2.5" flattener offers generous back focus:
Like the smaller 2" version, we have designed this flattener with a long back focus distance. So it is not a problem to add Off-Axis-Guiders, filter wheels etc. The recommended distance between the flattener's M69 thread and the focal plane is 91.5 mm for lenses with f/7 and slower.
For f/6, we recommend a distance of 106 mm.
For f/5.5, we recommend a distance of 111 mm.
The TS field flattener has deliberately been designed without focal reduction:
By concentrating on pure removal of field curvature, an exceptional result has been achieved without secondary aberrations like coma or astigmatism. Additionally, the flattener is not limited to certain telescopes or focal lengths. It is universally usable for nearly any refractors from f/5 to f/9.
-- Field flattener for f/5 - f/9 refractors without influencing the focal length
-- Free aperture: 61.5mm
-- Thread on camera side: M69 female
-- Threads on telescope side: M68 male and M63 female
-- Recommended distance between camera side thread and focal plane: 91.5mm
Scope of delivery:
-- Field flattener in robust carton box
Please contact us for availability information of the following accessories.
On the flatterner's left side, find the adapters to the focusers:
|M74-Flat25||100/600mm ED by TS Optics|
|OAZ3-Flat25||All Astro Professional Apos with 3" focuser (from 115mm aperture)|
TS Individual APO with 127mm aperture
TS Individual Achromat with 152mm aperture
William 3" focusers
|M63a-Flat25||2,5" Feather Touch focusers|
|FT3-Flat25||3" Feather Touch focusers|
|AP27-Flat25||Astro Physics 2,7" focusers|
On the flattener's right side, find adaptions to different cameras:
These adaptions allow versatile connections to nearly all common systems. In order to calculate the right distances, we noted the remaining distance to the focal plane. So you can determine the necessary extension tube for the correct distance.
A particularly recommended combination - the 2.5" Flattener and the 2-5" Off-Axis-Guider:
Depicted with flattener - ready for DSLR imaging
The off-axis-guider works perfectly with the flattener and can be screwed directly to it allowing the use of its full aperture. The adapter concept is designed for enough back focus even for (D)SLR cameras.
The connection scheme:
Via our short adaptions, you can attach a (D)SLR camera directly. We have ready systems for Canon EOS, Nikon and 4/3 (Olympus four thirds).
Alternatively, you can also adapt directly to T2 (Adapter 2-T2s) with 45mm of back focus that is enough for all existing Astro-CCD cameras.