Is it possible to capture the Milky Way with a planetary camera?

Question

The camera I'm using is the ZWO ASI120MCS. Is it possible for me to capture the Milky Way? If yes, then what is the settings? The optical tube I'm using is the Celestron TravelScope 70.

Answer 1

It will be possible for you to capture small areas of the Milky Way with that setup, but the angle of view you can see with that telescope will be much too narrow to be able to see what one usually means when they say "The Milky Way", which can stretch overhead from one horizon to the other at certain times of the year. You need a lens with a much wider angle of view than that, and a camera that can capture a large portion of the image circle projected by such a wide angle lens.

Answer 2

Sorry, but I would say that rig offers No Hope for Milky Way pictures.

Specs say that camera has a 1/3 inch sensor (tiny, like in a iPhone), and it is a 400 mm lens (extreme telephoto for that sensor size). That combination's Field of View (camera alone, no eyepiece) computes as less than one degree size (which is a magnified telescopic view). That combination should provide a very tightly cropped view of the full moon (Full moon can use reasonably normal daylight exposure times).

But the Milky Way is huge, and to be dramatic, instead needs a very wide view of most of the dark sky. Set up the rig to look at the moon once, and you should see the problem about the small field of view. The Milky Way needs a very wide view of most of the sky, more like a normal photo would provide.

That Celestron is a f/5.6 lens, so at f/5.6, the Milky way would need a couple of Minutes exposure at high ISO, like ISO 3200. However, without a rotating tracking mount, 400 mm on a fixed mount means the Earths rotation would produce long blurred star trails of a tiny spot in the Milky Way, instead of actually seeing the Milky Way. Long focal length magnifies the Earths rotation speed.

In contrast (NOT a practical solution, but only relating to the field of view), an iPhone with a 1/3 inch sensor uses a lens about only 4 mm for a typically wide snapshot photo view, but yours is 100 times more telescopic. So if a iPhone had any way to do a manual long shutter speed, the bare iPhone with its 4 mm lens alone (no additional lens) would be a more appropriate wide view for Milky Way (at f/2.2, if somehow it could do maybe 25 seconds exposure).

So for the Milky Way, I'd suggest a DSLR (with much larger, wider sensor, ideally full frame size), able to use a quite short lens (maybe 12 to 18 mm for the DSLR), and able to use high ISO (maybe 3200), for maybe at least about a 90 degree wide view, in maybe a 30 second exposure at f/2.8. That less magnified very wide view would not see the longer blur trails so well. But using a tracking mount would still be ideal.