How do iPhone and Flip camera work without a lens?

[vid83]

How does the iPhone and Flip camera (or similar) work without a lens?
I also noticed with the iPhone that you can get very close to a subject and it still focuses very well. Some cameras similar to the Flip even have a macro feature but don't have a lens that extends and retracts to focus.

So how do these cameras focus?

[budwzr]

They have no depth of field, just a pinhole in front of a CCD. Their focal length is infinity.

It's great for man-on-the-street videos like this one I took with my Flip:

http://www.youtube.com/watch?v=rVcPewPM1tM

[jagabo]

Note that a pinhole camera has very poor low light capability.
http://en.wikipedia.org/wiki/Pinhole_camera

[budwzr]

Or you can spend hundreds more, and move up to "bad" instead of "very bad".

[Steve Stepoway]

They're not pinhole cameras; they do have a lens. It's very small, VERY cheap (molded plastic, often), and has a very short focal length. Probably no more than 2 or 3 mm. With that short a focal length, essentially everything is in focus. They have essentially infinite depth-of-field, so there's no need to focus. It's also true that a lens that small is going to have poor low-light capabilities. But the quality of the lens is much more important for picture quality than is pixel count. That's why phone cameras make such crappy pictures. Really cheap lenses!

Steve

[MurbeckJackson]

They have a lens, but of course, only the little awful ones. They don't have any capabilities. So basically, they suck. 1080p my ass. I could get more 1080p out of my milk carton than those things.

[budwzr]

I think I detect a little jealousy from those that paid too much to get into HD, and don't want the proletariat in their clubhouse.

[edong]

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6694102&SRC...4-_-tigeremail