Hi-

Back in '89 I picked up a Bushnell 500mm mirror lens for use in taking pictures
of the Space Shuttle landings at Edwards Air Force Base.  Unfortnuately, the
1989 earthquake in the bay area kinda changed my plans for it.

I've had mixed results with the lens.  It is NOT autofocus with a little knob on
the side to do the focus.

One of the characteristics of a mirror lens that is a dead giveaway on the type used
is to look for specular highlights that are slightly out of focus.  The bright 
spots have a distictive "doughnut" shape to them.  You see the doughnut, you know
it came from a mirror lens.

High shutter speeds are a must with these lenses, even with a fairly sturdy tripod
mount.  My lens is also fixed at f/8, so that pretty much means fast film and an
accurate shutter.

I have taken moon shoots with this lens and the results were fair.  The trick there
is to compose and then to lock the mirror up (I use Nikon gear), put a piece of
black cardboard over the front of the lens, trip the shutter open (timed exposure),
wait for the shutter to stop shaking the camera, remove the cardboard from in front
of the lens for the exposure, do the exposure, put the cardboard over the front
of the lens and trip the shutter closed.  All in an effort to eliminate the
camera shake.  Of course, no wind.  Meanwhile, the moon has shifted from when you
composed.......  As an example, a 4X5 sized print of the moon filling most of the
frame yielded quality of a fair point and shoot camera with a normal picture.
Not too bad for a lens that cost under $1000.00.

For a real thrill and a good way to burn film is to try using these types of 
lenes on action shots!  Maybe with the autofocus, you will have better luck, however
I did prefocus on the plane of interest with mine.  The trick is to "track" the
object.  One cannot wait for the object to come into frame and mash the shutter.
Blurring will result.  The other trick is to compose with both eyes open.  This
takes some practice.  Use a static subject and look at it with one eye through the
viewfinder, the other open.  Notice where in the viewfinder the smaller subject
is in relation to the larger image in the viewfinder.  With a little bit of
practice, one can find that this really helps in lining up the shot.

Even these action shots required a tripod.  Panning with the tripod worked out
o.k.  I'm sure that motion stablized lenes would be better.

I've tried using a 2X converter with it, but the results were worse.  Maybe due
to a cheap 2X converter?

All in all, within fairly tight confines of picture taking, the mirror lens is
no where near as good as the "big glass" of the professional folks.  If you 
are doing wildlife shots, if you are doing wildlife, I would suggest you stay
clear of the mirror lenes, but with practice, one can learn to use these lenses
and they are certianly a LOT cheaper!

  Cheers,

    Rich S.
>>> Any chance to shoot some stars or the moon, just to see the image
>>> quiality at
>>> night ?
>>
>>Sometime - remind me in a month or so if nothing eventuates.
>>I've done some hand held or braced night shots but at f8 and 750mm
>>it needs a rock solid mount for good results.

>Back when my father was still repairing cameras he had occasion to repair a 
>Canon 600mm that came with a 2x converter specifically designed for it 
>(belonged to the local newspaper). We took my Canon camera out into the back 
>yard once he had fixed the lens, and took a photo of the moon using this 
>lens and converotr.. Just nicely filled the 35mm frame with the 1200mm focal 
>length. I was most impressed with it. 


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