Re: Cameras from Henry's

[Nigel Orr <Nigel.Orr@xxxxxxx>]

At 11:27 14/06/00 +0000, you wrote:
>What are the relative pros & cons of pinhole vs. lens varieties?

This isn't really a comprehensive list...

Pinholes have fixed focal length, lenses are potentially replacable to get
the right angle of view (board cameras seem to come with a fairly wide
angle lens).

Pinholes don't reflect light, and need a smaller opening, so are usually
better if the camera isn't to be seen when someone is looking for it (eg
ones hidden in clocks, smoke detectors, PIRs etc etc etc)

Lenses stop dust getting in- maybe pinhole cameras have a thin protective
plastic layer, not sure.  But lenses can collect muck too... (the first job
I used my Henry's camera for was inspecting the lower part of a chimney
from the inside before opening up the fireplace...)

Pinholes generally distort the image less than cheap lenses (not really an
issue in cheap CCTV cameras)

>which would be "better" for a front-door camera?

Probably a lens one.  The other, possibly more important thing to remember
is that mono cameras are _much_ better in low light than colour ones, and
usually more sensitive to IR if you want invisible illumination.

But if you are using IR illumination, be prepared for odd colour > mono
changes (I have one top which is black at the top, grey at the bottom, in
IR it looks like grey at the top, black at the bottom...) and glowing eyes!

Nigel


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