The Lake County Astronomical Society

Ditching the Star Diagonal

A discussion on the Talking Telescopes e-group noted that a large number of amateurs in Japan do not use star diagonals in refractors and SCTs. But this can result in having to position your head uncomfortably in many cases. To do this with at least some ease, you'd need a mounting that can be raised up high enough. A few American observers have tried it and report that, especially for planetary observing, there are some benefits to not using the diagonal. First of all, many star diagonals degrade the image somewhat both in terms of scattered light and image brightness. Second, some observers report that it seems easier to keep floaters in their eyes at bay in a look-up position rather than when looking down. Finally, they have gotten used to observing with both eyes open and with the non-observing eye looking at the night sky. They say the planet's image seems projected onto the sky and they are able to detect more detail - an effect that doesn't work well when looking downward with the lawn as the background.