Regarding star trails, look at it this way: the stars "move" 15 degrees per hour, as the earth rotates, right? 360 degrees divided by 24 hours. That works out to .25 degrees per minute. Your exposure was a minute, so that's how "far" the stars "moved" during the exposure.
Now, assume your lens covers a field of 90 degrees, it looks fairly wide. That means the stars "moved" 1/360 of the distance across your lens during the exposure. So the star trails would barely be discernible, "star smudge" is what you're gonna have, and not much of that.
Now make the same shot with a telephoto that has a field of view of, say, 5 degrees, and the stars will move 1/20 of the way across that FOV in one minute, producing a noticeable streak.
Here's my 66-second exposure from a couple weeks ago, at 17mm on FF sensor, about 100 degrees of coverage:
R. |
Add photograph to your favorites
Add photographer to your favorites
Photographer found comment helpful.
