DIY Parabolic Microphone?

[spotmeter]

For shooting landscapes, I thought it would be nice to have a parabolic microphone to to pick up distant bird calls and waterfalls. I'm hoping it might also reduce audio from people and cars behind me.

The commercial ones run from $1,000 all the way up to $4000.

Seems too costly for something so simple.

So I found a 24" parabolic reflector at Edmund Scientific for $80 and thought I would build my own, since I have lots of mics.

Has anyone done this before?  I found some DIY projects on line, but they all have the mic pointed away from the dish and it seems to be it would operate better if the mic was facing the dish.

If someone has done this, would appreciate some tips and directions.

Thanks.

[Matt Quinn]

Rarely used in the professional world...

A rifle mic with a suitable windgag would be the waepon of choice - Rhode do some cheap ones that perform very well for the price.

[Matt Quinn]

I should have added...

You may find the mic used is some form of hyper cardiod.  So the parabolic reflector serves two purposes. to shield the mic from sound from the rear, and provide a bit of 'boost' by supplying the rear of the mic with some 'extra' on-axis pick up...

I'd imagine one of the main issues with this is matching the mic to the parabola. Not just a case of getting the mic at the 'focus' of the parabola, but ensuring that when was directed into the 'tail' of the mic was properly phased so as to add - rather than cancel out - the on-axis sound gathered by the reflector...