On Sun, Oct 12, 2008 at 3:03 AM, karl shah-jenner
<shahjen@xxxxxxxxxxxx>
wrote:
*a laser focussing aid for macro and large format
photography (it can be used on any camera)
* a two / three beam
pulsed infrared camera trigger - so say when the fly is precisely *here* in
the frame (and 2 beams are broken) the camera goes off or, when
something cat height walks through this precise spot the camera fires, but
not if something dog height walks through. (I really should use this
thing more too!)
hmmn , this should be a very useful DIY for me... Is there a possiblity
of having more info on this one ???
Regards
Rush
both, or ..?
the laser focus aid was nothing more complex than
attaching a laser to the back of the viewfinder or ground glass screen where
it makes a sharp point of light - when the taking lens is open, the
light is projected out through the front of the lens, now if the lens is
focussed, it forms a sharp point of light on the subject, if out of focus, the
lens isn't collimating the point of light and you end up with a broad beam
(circle ) of light - simple!
it works nicely to quickly and accurately focus
large format cameras and for for macro work, and if you've a brighter green
laser, it actually does a pretty respectable job of aiding focus
indoors. Some of the brigher lasers even work well
outdoors!
As to the crossed beam widget, I have some
circuit diagrams lying about ehre somewhere - I can email them to you if you
like. I wanted to make these things commercially but stupid electronic
'anti-polutions laws' all but killed all small local manufacturers here
in Oz.
karl
