The Fluorostar's lens consists of three lenses with an air gap, which use FPL-53 ED special glass by Ohara, Japan as well as and lanthanum glasses. This extremely high-quality triplet design guarantees colour purity and image clarity which leaves nothing to be desired - a true high-end instrument!
Combine this apochromat with a suitable high-quality diagonal mirror from William Optics and you can see the stars with a level of clarity which other lens rarely provide. Binary stars separate and appear sharp, Jupiter's bright bands and zones reveal striking details and Saturn's rings appear as though they are flying past in a spaceship.
With its large aperture, without obstructions by the secondary mirrors required by reflectors, the wide world of Messier objects and ambitious deep sky objects is at your feet. Anyone who has ever looked through such a high-quality apochromat has been lost to the universe forever!
In the case of astrophotography, the large image circle provides illumination, even for full-frame cameras. Combined with the Flat6AIII flattener by William Optics, it produces an faster aperture ratio and a flat image field right to the edges. The flattener can be securely screwed on to the drawtube.
The drawtube has smooth, precise 1:10 reduction, a temperature display and a large adjustment range. It effortlessly supports heavy astrophotography equipment which can also be rotated to find the best position on the sensor.
A further special feature of the William Optics apochromats is the specially calculated Bahtinov focus mask:
These new focus masks made from optical acrylic glass provide 92% transparency.
The imprinted pattern provides a diffraction structure which is around three times brighter than classic metal masks. The acrylic glass masks, therefore, produce a clearer diffraction pattern and enables focusing with the help of fainter stars.
The FLT91's Strehl value is 0.95+ and it can be used with the following cameras for astrophotography:
- Canon EF, RF
- Nikon F, Z
- Sony E
- Pentax K
- Fuji X
This high-quality triplet apochromat is also suitable for CMOS and CCD cameras!
The lens tube has a retractable dew cap and can therefore be converted to a practical size for transportation. Furthermore, at 4.16kg, it weighs almost nothing. The FLT91 is an ideal travel telescope.
