Best for general deep-sky imaging and visual observing when the mount, camera format, and correction hardware are chosen as one system.
CDK20 F/7.77 Lens Group (Converts CDK20 F/6.8 model to F/7.77) sits in the telescope slot for general deep-sky imaging and visual observing. The important buying question is whether the optical design, focal length, and mount demands match the targets you actually shoot.
Treat it as a system component rather than a standalone tube: the mount, corrector, camera, and focusing hardware decide how good the final data can be.
Best paired with
Corrected field flattener or reducer when the design requires one
Cooled APS-C or smaller astro cameras matched to the image circle
Autofocus, guide scope or OAG, and a mount with comfortable payload margin
Not recommended for
Large full-frame sensors unless the corrected field supports them
Very small travel mounts near their realistic imaging payload limit
Buyers expecting one telescope to be ideal for every target size
Where To Buy
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