I don't know if this pertains to what ita's wondering about... and someone correct me if I'm wrong here...

The depth of field (how much stuff is in focus - I think that's the right term) varies depending on the aperture (size of the opening to the lens) of the camera. On good cameras this can be changed. A small aperture produces the most depth of field (so stuff further away from the thing you focused on will still be in focus). The downside to a small aperture is that you need to increase the exposure time to compensate for the reduced light. Consequentially a small aperture is bad for action photos. This is why you are much more likely to see a blury background in an action photo.

Here's a study involving the possible use of optics in Renaissance Painting.

[link]

And here's a very comprehensive article on DoF in Photography: [link]

Thanks, Matt!

This is why you are much more likely to see a blury background in an action photo.

That, and the option to pan with the action to keep the primary object in the same position, giving the background a speed blur effect.

I'm pretty familiar with depth of field from a camera POV (so to speak), and until Twilight Zone disturbed me, I hadn't considered it as a convention, an adaptation to a technical limitation that's become language. But not in every medium.

I've been googling a bit, and damn, I wish I had time to take an Art History bachelor's. I may be reading this all day.

eta: Heh, Sue. I just found that site too.

ita, you might find this book interesting: Art & Physics. I don't think I fully agree with the author's premise, but still, lots of interesing stuff. I don't remember off the top of my head if the book deals with focus issues, though.

The shark hunting was adorable.

That was almost unwatchable for me -- I kept picturing them wounding one but not killing it and sending all the other sharks in the water into a feeding frenzy which would result in at least one of them having their feet bitten off.. Seriously, who hunts sharks with a stick???

Thanks, Tommy. I've put it on hold at the library.

Seriously, who hunts sharks with a stick???

I bet The Rock would. Vin might have, a couple years ago. But not now.

Seriously, who hunts sharks with a stick???

I know. I could not figure out how throwing a pointy stick into water actually kills something. But it was cute anyway!

This is funny. I emailed our conference director the story about Oscar Goodman saying that we should put a bottle of gin in his gift basket. She had already done it. BWAH!

I could not figure out how throwing a pointy stick into water actually kills something

This is probably why you're a lawyer and not an Ojibwe hunter.

Well, in conjunction with the whole white thing.

The guys were cracking me up last night. First they decide to go after some highly venomous snakes, and then decided to throw pointed sticks at the sharks the snake carcasses attracted.