Corporate In a relatively short time, William Optics has established itself and its products as one of the world leaders in short-tube, highly-portable refractors, and has achieved quality recognition for many accessories such as the well celebrated WO Diagonals.
We plan to keep producing fine instruments both for the entry-level and the top-end segments. In the coming year, you will have many pleasant surprises: on top of a whole new range of larger Apochromatic telescopes, we will begin marketing new accessories and binoculars for all pockets.
The William Optics GT 81 apo stands for optimal chromatic correction and best possible contrast - a powerful travel telescope for observation and photography.
Aperture 81 mm
Focal length 480 mm
Focal ratio f/5.9
Multicoated FPL53 triplet lens with air gap
2.5" RAP focuser with M63x1 connection thread, as well as 2" and 1.25
William offers with the REDCAT61 Astrograph a very well corrected telescope for astrophotography up to full frame format.
Aperture 61 mm / Focal length 300 mm / Focal ratio f/4.9
Petzval design with chromatic aberration free FPL53 objective (4 elements in 3 groups)
Very well corrected and illuminated image field up to full frame format - the corrector is built in - no more adapter battle necessary
Camera connection via M48 male thread (suitable adapters are available) - working distance 55 mm
360° rotation of the camera for the right display window
Focusing via internal focusing (William Internal Focus Design - WIFD) as with telephoto lenses
Tilting option for individual adjustment of the camera sensor to the telescope
Flexible dovetail bar at the base (long version), suitable for Vixen style and Arca-Swiss saddle plates, in addition with 1/4" female photo tripod thread
Nylon carrying bag and Bahtinov mask for astrophotography are included in delivery
Innovative and revolutionary William Optics design combines precise internal focusing with the highest quality optics available to create the ultimate apochromatic refractor for astrophotography
FPL53 Triplet Lens
Aperture 81 mm, focal length 480 mm
Internal focusing prevents image shift and vignetting
Saddle bar handle for mounting the guiding telescope
The FLT 91 is the perfect apochromatic refractor for visually and photographically observing astronomers who demand the most from a medium-sized telescope.
Three-element design with FPL53 glass
91 mm aperture, 540 mm focal length
Rack and pinion focuser with gear reduction and "Rotolock" clamp
Field rotator with degree markings and position lock
This three-lens apochromat with FPL-53 element and STM coating delivers color-pure, crisp images! Stars are pin sharp points, bright objects like moon and planets show no color fringes, but a lot of details!