[time-nuts] finding time astronomically.

[Mike S]

On 1/23/2012 3:02 PM, Jim Lux wrote:
> How well could you do with something like the camera in the iPhone4
> facing up. The front camera is VGA resolution

A lower bound can be estimated.

A cell phone (iPhone 4 rear camera) camera sensor has a resolution of 
what? ~2600 pixels wide with a 45 degree field of view - that's ~ 60 arc 
seconds per pixel, which is about 4 seconds of time. The Dawes limit is 
about 1 second (17 arc-seconds) for a perfect .25" lens. Obviously worse 
with a VGA resolution camera.

Can such a camera even "see" stars?