Focusing on the moon

[armis]

Hello all, and hi! This is my first post here. I live in France, and I recently picked up photography as a hobby. Can't say I have much to show, though you're welcome to some shots of Iceland, Jordan or Singapore if you want to see what I like to shoot.

So anyway, yesterday the night was clear and the moon was out, so I tried taking a few pictures. I think I did all the right things: mirror lock up, tripod, cable release, stabilizer off (I also tried with the stabilizer on just in case). Still, every shot I took came out fuzzy. this is the best I could do. It's a 100% crop with two passes of unsharp mask (the first was something like 200%/2,0/1, the second 100%/0,5/0). Still not quite tack sharp.

While I realize my lens (Canon EF 55-250mm) doesn't have the best optics in the world, I think it should be able to do better than that.

I'm wondering if focus isn't the issue. I shot at f/8 since that should give me the best sharpness (optically, i.e. assuming perfect focus) and allows faster shutter speeds - I was concerned that at f/22 I'd get down to speeds low enough that the moon's movement would start being an issue. Still, f/8 gives me a shallower depth of field, though I don't know if it should matter at that distance. I do know that it was too dark and the moon was too small for me to manually focus, so I relied on the autofocus. I considered hyperfocal focusing, but I must have been doing something wrong: I figured out the hyperfocal distance was about 400m, but the focus ring on the lens doesn't seem to be metered (and if it is, I assume that like others I own it goes something like 30cm -> 50 cm -> 1m -> 2m -> infinity, so finding the 400m mark is a bit tricky).

Anyway, regardless of what I may or may not have been doing wrong, is there a surefire way of achieving perfect focus of the moon (or other small objects at infinity)? Thanks!

[digirebelva]

Understand that just because you are shooting at night in this case does not mean extremely slow speeds. The brightness of a full moon ususally warants a shutter speed of close to 800 give or take a few stops depending on your iso.

As far as sharpness, your lens is known to be soft at 250mm even stopped down to F8, as most consumer lens tend to be.

[tjc]

Hi armis...

Have a look here

arlon really does know his onions when it comes to shooting the moon and there`s some great info/advice and pics in there too.

One thing I know is recommended though is to always manually focus for the best sharpness.

Also have a look here loads of good info etc from Jeff Smith too.

I manually focus for every type of shot I try and rarely rely on auto focus for anything.