APM Riccardi 1x universal field flattener with M82 thread (Model 2)

APM Riccardi 1x universal field flattener with M82 thread (Model 2)

Massimo Riccardi, famous optical designer from Italy, designed for APM Telescopes a new 3 element 1x field flattener for apochromatic telescopes. The Model 2 has been designed to flatten and correct the field of apochromatic telescopes over 140 mm of diameters and over 1000 mm of focal length.

Assembly

The connection to your telescope occurs over an M82 x 1 thread. CCD side there is a M68x1 connection thread and also a M77x0.75 connection thread (highly reccomended for heaviest imagin trains).

For the correct adjustment of the reducer/flattener we suggest to use an optional tip-tilt adjustment flange.

Backfocus

The new flattener allows a generous working distance from the thread to the focus of more than 90 mm (see attached file) so that all common accessories such as filter wheels will find space.

Usually the field flattener is screwed onto the focuser. The right backfocus for your telescope you will find in the enclosed PDF chart (see below). The total optical path of field flattener plus backfocus plus focus change is between about 170 mm and 210 mm.

The correction is made for chips up to 60 mm diagonal and perfect for the best known Kodak KAF 16803 chip.