Starizona Apex ED S 0.65x Reducer / Flattener - LONG Version
Starizona Apex ED L 0.65x Reducer / Flattener - LONG VERSION
This product listing is the "L" (long) version that has been designed for (mainly) apo refractor telescopes with focal lengths over 500mm.
With the Apex ED reducer, an f/5.5 apo refractor becomes an incredibly fast f/3.6 astrograph. A slower f/9 telescope like an RC becomes a speedy f/5.9 system. The reduction factor provides a 1.5x wider field of view and shortens exposure times by a factor of 2.4x!
The Apex ED reducer features extra-low disperion glass to eliminate chromatic aberration and to provide sharp star images over a 30mm image circle, capable of working with most popular CCD, CMOS and DSLR cameras up to APS-C format.
The Apex ED reducer fits into a standard 2" focuser. It has M42 T-threads on the camera side, and it can accept a standard 2" (M48) filter on the telescope side for easy use of light-pollution or other filters. On Meade ACF telescopes, the Apex can be attached using a 2" visual back.
For select refractors, we make optional threaded adapters to allow direct threaded attachment of the Apex reducer, eliminating the possibility of tilt introduced by the standard focuser clamp ring.
(These above mentioned adapters are only available on backorder from 365Astronomy...Please ask.)
"L" and "S" Versions
To optimize the Apex ED for the best possible performance, there are two versions of the lens. The "L" version is designed for telescopes with focal lengths 500mm and longer. This includes most larger (100mm+) refractors and all RC and ACF telescopes. The "S" version is for telescopes with focal lengths from 300-500mm, including most 60-80mm apo refractors.
We at 365Astronomy also asked the manufacturer what would be the effect on achromatic refractors and were told that the Apex will work with an achromat in the sense that it will indeed flatten the field and reduce the focal ratio, but there will be the chromatic aberration still there from the native objective, and that would be the limiting factor. If someone wanted to eliminate the color issue (say by only shooting H-alpha) the Apex would probably work reasonably well. But definitely intended for apo refractors (both doublets and triplets) and also RCs.
The nominal backfocus distance from the Apex ED reducer's T-threads to the image sensor depends slightly on the focal length of the telescope. It is at least 55mm in all configurations. The table below shows the optimum backfocus for various focal lengths. Please contact us for help in choosing the right adapters or spacers necessary for your setup.
- Reduction Factor: 0.65x
- Image Circle: 30mm
- Backfocus: 55-62mm (depending on telescope focal length)
- Optical Design: 5 elements with ED glass, fully multi-coated
- Barrel Diameter: 2"
- Camera Thread: M42 (T-thread)
- Filter Thread: M48 (2" filter)
- Overall Length (Apex ED L): 2.97"
- Weight (Apex ED L): 0.7 lbs
- Overall Length (Apex ED S): 3.26";
- Weight (Apex ED S): 0.72 lbs
Images are for demonstration only.
|Weight in Kg||0.1|