|
Yes, binoviewers do work in Dobs. To maximise the fully illuminated true field of view, you need a corrector that gives an f-ratio equal to 2 x optical path length of the BV divided by the clear aperture of the BV. Typically this means about f/10. So an f/5 Dob will need a 2x OCA.
Most people seem to think that the main function of the OCA is to let the BV reach focus. Not so. It is essential to make use of the full aperture of the scope. But even then, you will be limited to medium to high powers. Something to keep in mind. It depends on the scope's aperture and f-ratio, but say in a 10" f/5, you will be able to use a BV from ~100x up but even then only the central ~50% of the FOV will be fully illuminated. This is not so obvious visually. People usually look for vignetting to decide whether there is loss of illumination. But this is a poor indicator as the human eye+brain only picks up vignetting when most of the incident light is blocked.
|