Field leveller Skywatcher

Field flattener Skywatcher for all Refractor and Ritchey-Chrétien telescopes with a minimum 2" focuser and a focal ratio between f/5 and f/9.

This revolutionary new field flattener system is the first to offer a number of advantages not offered by conventional flattener systems:

-- Maximum possible illuminated field of at least 40mm vs. the 37mm aperture typical of traditional flattener systems.

-- Excellent performance over a wide focal range for a very diverse assortment of refractors with focal ratios between f/5 and f/9.

-- Offers a large BackFocus distance from 108 to 128mm. This allows you to adapt a wide assortment of additional accessories between the flattener and the camera, such as off-axis radial guides, quick filter changers, etc.

-- It can be used in multiple adaptations. The flattener uses the typical 2" (M48) filter thread.

Technical Specifications:

-- Field flattener with blackened lens edges. Multi-Treatment.
-- No focal reduction!!! Only corrects the field.
-- 40mm diaphanous aperture.

-- 2" to T2 adapter.

-- 15mm extender ring

Recommended distances between the M48 thread of the flattener and the camera sensor position:

For most Refractors the optimum BackFocus distance is between 108 and 128mm from the M48 thread to the camera CCD sensor position. Practical experience has shown that the flattener has a high tolerance to deviations from the ideal distance. For example, a deviation of 5% does not cause any deterioration of image quality on an APS-C type sensor typical of DSLR cameras. For smaller sensors (typical of astronomical CCDs) even larger deviations are acceptable. In any case, one must keep in mind that the higher resolution of many CCD cameras forces to pay the utmost attention to be able to respect the distance accurately as much as possible. Most of the tests have been performed using a DSLR camera with a 15.1x22.7mm sensor.

Suggested distances from the M48 thread of the flattener to the camera sensor would be as follows, depending on the focal length of the telescope:

-- Focal length -- Focal length 450-490mm: 123mm
-- Focal length 500-550mm: 118mm
-- Focal length 560-590mm: 116mm
-- Focal length 600-690mm: 113mm
-- Focal length 700-800mm: 111mm
-- Focal length from 800mm: 108mm

To achieve these particular distances it is a matter of playing with different combinations of 2" extension arms, T-thread extension arms, etc... All available at Telescopiomania!!!!

Field flattener Skywatcher for all Refractor and Ritchey-Chrétien telescopes with a minimum 2" focuser and a focal ratio between f/5 and f/9.