Originally posted by Lowell Goudge Leo
A star, regardless of the "apparent size" is always a point source and will always be a single pixel. the moon or a planet would be better, since you can see some detail to focus on. and from that point onward, just leave it alone. I doubt the difference in focus from 1/4 million miles to 100 million light years impacts things much.
you should be able to focus manually, or just put the lens to infinity (unless it is defective and/ or focuses past infinity such as a telescope)
Many visible "stars" are not "single points" but are, in fact, double stars, or more, once you put enough magnification on them.... This is clear in many photographs online where a single photograph has stars that appear bigger than others. Not only that, but, diffraction (from the atmosphere) takes it's toll on the light coming from distant stars, and it affects them differently depending on their relative brightness.
Are these "stars" all the same size? Is it because the person is incapable of focusing correctly?
APOD: 2005 October 13 - Alnitak, Alnilam, Mintaka
This is a link to a NASA site's photo of the day, so it was probably not shot by "amateurs", even if it wasn't captured by NASA itself. To me, this photograph has big stars, and small stars. Some are more than one pixel wide. None are very big, but some are (apparently) bigger than one pixel, certainly bigger than others.
I agree 100% with Leo that I look forward to the live view features in the K20D for astrophotography. I think it's going to be a great boon to how I actually use my Pentax camera. In fact, it's probably about 50% of why I am looking forward to buying a K20D.
You _should_ be able to focus manually or put the "lens" to infinity, but that is either impossible because it's a telescope and has no "infinity" or because the darn viewfinder is so dark that in-focus and oof are not really that different in the (DARK) optical viewfinder. (and I've found that to be true, even with my 50/1.4 shooting constellations like Orion.)
I will welcome the availability of live view, even if I don't plan to use it for 90% of my "terrestrial" photography. But like many technological improvements, it's frequently difficult to envision how you could use a new technology until you actually have it in your hands, then after that, it's difficult to imagine living without it.
I also think this will make the Pentax DSLR camera more tempting to people coming from P&S type devices, and I think that will benefit Pentax as a company directly, and me as a person who has bought into the Pentax system, indirectly.
-Chris