Vixen Reducer/Flattener HD Kit for FL55SS

Sharp star images throughout a photographic field of full-frame DSLR cameras.

The flattener HD lens improves off-axis image quality greatly with a minimum charge of the focal length. The focal reducer HD5.5 reduces the focal ratio of the FL55SS scope from F5.5 to F4.3 (by 0.79 times) while keeping a 44mm image circle that covers imaging sensors of full-frame DSLR cameras.

A minimum loss of light toward the edge of the photographic field. A 86% of illuminated field of view is sufficient for the full-size imaging sensors.

Generally, astrophotographers are annoyed with the drop-off of light toward the edge of the illuminated field of view when taking faint deep-sky objects with a telephoto lense or dedicated astrophoto instrument. Although this may be corrected by complicated image processing on a PC, it all depends on the image quality of an original photograph. The focal reducer HD5.5 works to keep a large 86% illuminated field of view even at the very edge of a 44mm image circle in combined with the flattener HD lens. Astrophotography of nebulae and star clusters is fun with the focal reducer HD Kit.

Illuminated field of view at the edge of the photographic field.

86% with the use of DSLR cameras with the full-frame size of imaging sensors. 97% with the use of DSLR cameras with the APS-C size of imaging sensors.

Comparison in light loss between the FL55SS with the flattener HD lens plus focal reducer HD5.5 and a standard telephoto lens or astrograph.

FL55SS with the flattener HD lens plus focal reducer HD5.5

Standard telephoto lens or astrograph

Ultimate light transmission coatings for extremely high contrast images.

The same anti-reflection AS coatings that are used for our high-end VSD100F3.8 renowned for extremely high light transmission (99.9% per surface) are provided on each of the lens surfaces of the flattener HD lens and focal reducer HD5.5. Besides, elaborate matte-finishes are given to eliminate internal reflections and loss of light completely.

Sample images "Veil nebula" "Debeb and North America nebula"

Setup configurations