# Technical question for the lens "gurus" out there...

Discussion in 'Photography' started by David Harper, Jun 30, 2003.

1. ### David HarperGuest

I'm still new to lens calculations, but I was wondering if 'point and
shoot' cameras can actually focus on objects at infinity?

I imagine camera designers design for the most frequent distance to
subjects (such as 15 or 20ft), and there's some range where the
subjects are 'close enough' to the ideal distance to the subject that
they appear in focus. Am I correct in this assumption?

I ask these questions as I recently started looking at cameras for use
on a high altitude project, and I'm selecting a camera based on
weight, field of view, auto-winding capacity, quality (including the
ability to focus at infinity). However, I'm worried that some "point
and shoot" cameras that look to be good candidates would result in
poor quality photos of the horizon / ground. Any advice on what type
of camera/lens would be good for high altitude photography would be
welcome!

Thanks in advance for any advice or information anyone has to offer!

Dave

David Harper, Jun 30, 2003

2. ### WinkenBlinken& NodGuest

No, they are too far away.
Study the term hyperfocal distance, and you will be amazed.
Are you refering to aerial photography?
Seriously is this a climbing activity, or is it from some sort of aerial
vehical as the cameras would be different.

WinkenBlinken& Nod, Jul 1, 2003

3. ### WinkenBlinken& NodGuest

Sounds to me like your planning on putting a camera in a radio controlled
model airplane right? If so and unless you are planning on taking close ups
while landing or some other such activity what difference does focus have to
do with the overall picture. I have taken hundreds of thousands of
photographs out of aircraft and never once used a camera that could be
focused at anything other than infinity. But that could even have been at
the hyperfocal distance, but I would think not.
If my assumptions are correct I would go for a cheap point and shoot that is
fixed focus, and that you are able to get to the contacts for the shutter
and connect them to one of the solenoid channels in order to control the
camera.

Ed

WinkenBlinken& Nod, Jul 1, 2003
4. ### David HarperGuest

Close, it's a high altitude balloon.
Yeah, but "focused" at infinity with a point and shoot camera is
basically the same as "almost out of focus, but technically not
quite"... correct? For a camera fixed-focused at the hyperfocal
distance, a dot in infinity will appear the exact same size as the
circle of confusion, and not really perfectly focused... correct?
Unfortunately, most point and shoot cameras I've taken apart are
spring-loaded with a mechanical mechanism directly linked to the
button, meaning no internal solenoid. So I purchased some solenoids
to be used externally to press the button... but not that it really
matters to the current discussion...

Dave

David Harper, Jul 1, 2003