Andromeda test
▶ I recently purchased a 6-inch Schmidt Cassegrain Telescope (SCT) and decided to get a second, faster scope to do wide-field observing with the same mount. I settled on a 4-inch refractor. When I turned my Go-To mount to the Andromeda Galaxy and observed with both scopes I was surprised to find the view through the 4-inch refractor was more impressive. I know that a wider field of view is preferable for an object like M31, but I thought that with an extra 2 inches the SCT would give better views. I wondered whether the SCT’s secondary mirror ‘cancels out’ its extra 2 inches, or whether it’s just a matter of preference?
Fionn Daly, via email