ZWO 107mm f/7 APO astrograph
The FF107 is a flatfield astrograph, part of the range that also includes the FF65, FF80 and FF130 models.
 
Optical design
Instead of buying additional flatteners, calculating the back focus of the flattener, or making a tedious connection to set the correct distance, astrophotographers can simply equip it with all sorts of photographic accessories, keep the object in focus, and then the entire optical system is perfect for the figure set.
 
High quality glasses
The FF107 has an aperture ratio of 1:7 and a focal length of 740mm. The FF107 is a quadruplet design with two ED lenses, allowing excellent control of chromatic and other aberrations. With its self-leveling design, the FF107 offers great advantages for astronomical photography. It offers more than the full-frame image circle and has a fine spot diagram with only tiny distortions of the peripheral stars.
 
Practical details

The FF107 comes with an extendable dew cap, a high quality CNC milled and painted tube and decoratively designed parts. The OTA weighs 5.7 kg, the entire package with pipe clamps etc. weighs 6.9 kg. The sturdy 3" focuser comes with a 360° rotator with dials and a viewfinder shoe. M76, M68, M54 and M48 camera adapters are also included, and the M48 adapter has an M48 female thread for installing 2" filters.

The back focus is always measured with the draw tube completely retracted:

♦ 79 mm from M48x0.75 external thread
♦ 99 mm from M54x0.75 external thread
♦ 119 mm from M68x1 external thread
♦ 149 mm from M86x1 external thread
♦ 120 mm from 2" receptacle

 
Opening: 107mm
Focal length: 740mm
Aperture ratio: F/7
Lens: Triplet lens with air gap
Corrector: Single Element Corrector
Coating: All surfaces are multi-coated
Illuminated and corrected image field: 44 mm diameter
Focuser: adjustment range 110 mm
Back focus: Maximum distance 149 mm from the M86x1 thread
Connections on camera side: 1.25", 2", M86x1, M68x1, M54x0.75 and M48x0.75 thread
Filter thread: 2" filter thread is included in the M48 camera adapter
Dew cap diameter: 134 mm
OTA weight: 5.7 kg
Weight: 6.9 kg including clamps and rail
Weight of the suitcase: 4 kg


♦ FF107 Apo
♦ CNC clamps with carrying handle and prism rail
♦ Viewfinder shoe mounted on the focuser
♦ Transport case