Focus or motion blur?

[Jehu]

This was a 5 minute exposure. I was at the end of the Berkeley Pier looking out over the old pier. I'm pretty sure I got a good focus at infinity by using the lights on the Golden Gate Bridge. The old pier is 160' from my setup. I would've thought that it would be in pretty sharp focus with a 240mm at f5.6. It's also my first shoot using a fresnel for focusing.

Do I have a focus problem or is the pier moving enough to do this?

[mdm]

I would have used a little front tilt, focused on the pier and stopped down more. DOF is much less infront of the focus point than behind it, 1/3 in front to 2/3 behind, so the lights are infocus and the hills but not the pier.

[Jehu]

I guess I should check up on DOF rather than just assuming. Focus at infinity puts the near focus (.1mm CoC) at 300'. I need to carry a DOF calculator with me I suppose. I wonder if there's a Droid app for that.

Anyway, the posts to the right of the pier are over 300' away and they don't appear sharp either. That's what got me thinking about motion.

[Scott Walker]

I wonder if there's a Droid app for that.

Search DOF Master, it is a good app for the iPhone, possibly a Droid app as well.

Acording to DOF Master your near focus limit would be 323 feet which would be pushing it to hope the pier would be in focus.

[Axon990]

I use Photography Assistant for my Droid. Works great, and has an exposure calculator too.

[Alan Davenport]

For a 240mm lens focused at infinity, 160 feet would not be within your DOF at f/5.6. And that's what the image appears to be, just not quite in focus (vs motion blur.)