Beardy wrote in post #13875309
Todd/anyone, quick question. I'm using a T2i with a 16-35 L lens. I can't seem to ever get my night shots in focus. Looking on the screen after the shot everything looks great. Then I get it home and on the monitor and see it's all out of focus. Help? I've tried zooming in after taking a shot but it's alot of hit and miss, mostly miss.
A trick I use, if available, focus on distant lights, street lights porch lights, doesn't matter as long as they are far enough away they require you to focus at Infinity.
Other than that and what has already been recommended, the only thing I can add is to use a laptop computer with your EOS Utility if you can. That way you can take test shots and get a better look at them to see if they are in focus or need adjustment. Or use Live View via the EOS Utility on the laptop and you will be able to see a bigger picture that will help you get better focus.
When using live view to focus on stars, Increase the ISO as High as you can, and then increase the Live View magnification so that you can see the stars good enough to achieve focus.
Todd Lambert wrote in post #13875534
With zooms, it's important to find the point on your lens that it's actually at true infinity. This point can vary a bit and even lining things up on the lens, doesn't work all the time.
It's not just zoom lenses, but pretty much any lens with Auto-focus..
For smoother operation as well as to reduce vibration or wear and tear from a sudden stop, Lenses with high speed auto-focus go beyond infinity and then back.
However, sharp focus isn't only a function of the lens, but of the camera body as well.
Getting a physical feel for / familiarity with how your lenses and camera body function together will help considerably.
Trying to convince the camera to work perfectly under dark skies with nearly no available light is next to impossible. This is why we must rely on or skill and familiarity with our own equipment when we are in the dark. It's going to take a little time and practice. Even then you won't get it every time. Just keep at it and don't give up.