Free Shipping to lower 48 states for all orders over $100
This field flattener is designed to work with the Altair Astro 80mm F6 Super ED Triplet APO, and has an M48 rear thread adapter for connecting your DSLR or CCD camera. All triplet refractor lens systems with good colour correction exhibit some natural field curvature which, while not relevant for visual observation, can be visible in astro-images. This field flattener screws directly into the rear focuser rotator of your Altair 80mm F6 ED triplet APO, converting it into an astrograph with a flatter photographic field than a triplet lens system alone. It does not change the focal length of the telescope significantly enough to affect subject framing.
Altair PlanoStar Field Flattener specification:
The PlanoStar 80m EDT field flattener corrects for field curvature and improves images taken with cameras up to APS size, allowing more of the photographic field to be utilised.
The ideal distance to CCD sensor from the rear of the conical adapter flat shoulder excluding the M48 thread is 54.7mm. Please see the diagram in the thumbnail images.
The flattener contains 2x 2" FMC lens elements which, when combined with the front triplet lens system, produce a 5-element optical system with a flatter field than a triplet alone.
High quality multi-coatings on all surfaces ensure maximum transmission and almost zero reflections. These coatings are so efficient, the flattener lenses are almost invisible at first glance.
The flattener is threaded directly to the rear of the focuser for optimum rigidity. Simply remove the 2" pushfit adapter and screw the flattener into the rear of the focuser.
The M48 rear aperture reduces Vignetting compared to standard 42mm Photo T-Thread.
The optimum distance from the rear flat shoulder (excluding the m48 thread) of the flattener to the CCD chip in your camera is 54.7mm, however tests indicate that the flattener is tolerant about 1.5mm either side of this distance. The smaller your CCD chip, the more tolerance you have to work with.
To connect a Canon DSLR you need a Canon/Nikon M48 DSLR Adapter
Recommended for the Altair PlanoStar 2" 1.0x Flattener for 80mm F6 Triplet APO