|mild_mannered_super_hero wrote: |
nice post, its interesting to see everyones different hobbies. im curious to know the power on your large scope ? i know nothing of such things but im very familar with a rifle scope. in that world a 40 or 50 mm objective and 18-24 power is considered quite large. regards mmsh
Generally speaking, and I'm oversimplifying here, astronomy scopes don't talk much about "power". For the most part you are looking as EXTREMELY faint objects, unless you are looking at something like the moon, so the real objective is light gathering ability. Again, I'm oversimplifying but at least in reflector type scopes it's all about the size of the primary mirror. The larger the mirror, the more light, and therefore the fainter objects you can resolve. An 8 inch mirror is better than a 6, and a 10 is better yet, and so on and so fourth. You have to remember looking through that eyepiece looks nothing like the amazing photos Hubble, for example, delivers. Those kind of photos only come from very long time exposure photos. In the days of film, the scope had to be very carefully guided, usually with a motor, to follow whatever you were photographing, as it moved across the night sky. In today's digital world, this is instead usually done by taking multiple snapshots, somethines hundreds, and cumulatively combining them on a computer.
Now you can and must use various eyepieces called "objectives" to achieve magnification when looking through the scope, bearing in mind, the more magnification, the dimmer the overall view is.
When using a digital CCD, this is less of an issue. What becomes important then is the resolution of the CCD. Just like HDTV has better resolution than Standard, and 4K is better than HD, and 8K is clearer then 4K, the same goes for telescopic CCD imagers. What that means is the higher the resolution, the tighter you can crop and blow up the image, which is effectively the same as having a zoom lens in a camera or rifle scope.
The thing about all this is, though, is that glass, good quality glass, is EXPENSIVE. You can easily spend thousands of dollars on a good 8 or 10 inch Cassegrain style scope. The other thing to keep in mind is aside from the size issue is that glass is very heavy. This really limits the portability of a really good "light bucket". If you live in an area with a lot of light pollution there's only so much you can really see no matter how good your scope is.