Re: Questions on fisheye lense, and step-up rings

<upgrdman@xxxxxxxxxxxxxx> wrote in message
news:1129433114.775621.160400@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> what i really want to know, is if it's possible to use this lense on my
> current camera, and still get the 180 degree FOV... even at full wide
> angle, with the fisheye circle really small, it's still not a 180 FOV
> picture.
>
> would a cheap teleconverter lense attached to my camera, and then
> attaching the fisheye to the front of the teleconverter give me what i
> need, or would it severely reduce FOV like using my camera's built in
> optical zoom does?

On a 35mm camera you only need a 50mm lens to get full fisheye, so I doubt
that the teleconvertor would be necessary, and would presumably further
degrade the image. If the image is not contained in a circle that almost
touches the top and bottom of the frame when you zoom to 50mm equivalence,
and shows less than 180 degrees, my guess would be that the apreture on your
camera's lens is the problem. On a 50mm lens on a 35mm camera, if I set the
50mm lens's aperture to f2.8 (and more so at f4) the aperture blades
effectively crop the image, reducing both the size and the FOV. I believe
maximum aperture on the S2 is only f2.7. Presumably if its at maximum
aperture then no blades will be cropping the image, but the narrowness of
the aperture may still cause the same problem. You should be at least sure
that you are using the maximum aperture (on your camera's lens - the fisheye
adaptor should be stopped down, basically as much as possible) and
experiment with different apertures.

You should also try the adaptor on a 50mm lens on a 35mm camera on a tripod
to see the best possible image you can get. If it's the same as mine, its
really not that impressive, and every step you take away from that ideal
setup is only go to degrade the image further.

--
Apteryx


.

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