a proposed system for capturing wildlife: your opinion please

Hello,

I originally posted this in the astro.amateur group as I am an amateur
astronomer, but am seeking opinions on the following:

Recently, I have become somewhat interested in trying to capture daytime
images of wildlife and landscapes. However, I am having difficulty deciding
what direction to take. After browsing the archives of this group, entering
the wildlife realm looks like it might be an expensive
proposition, but I have an idea and I wonder if it would work:

For astronomy, I have been using an ETX-90/ webcam combination for nearly 3
years now with success (for photo.digital group: The ETX-90 is a telescope
of the Maksutov-Cassegrain design with a 90mm aperture and 1250mm focal
length). Why couldn't I just afocally couple (this means to attach a
standard digital camera to the eyepiece of the telescope) a digicam to
the ETX-90 ota (optical tube assembly), with the combination mounted on a
tripod? If the digicam I
use has a zoom, I would have a range of magnification just like I would with
a telephoto lens. Does anyone use a similar combination to image wildlife?
I'd be interested in seeing your results, so share your website if
appropriate.

I realize that there are some DSLRs, like the Canon Digital Rebel, that
could directly couple to the ETX or even a telephoto lens, but the price is
beyond my budget. The afocal method I could already do since I have the ETX
and a Scopetronics wide angle eyepiece- the only thing I would have to add
would be a digicam and would appreciate recommendations for a suitable, low
cost camera.

Like I said, the aforementioned is just an idea and wouldn't cost me much-
that is, if it would work.

Thanks, in advance, for your response.

Ian Robelot

Ian Robelot wrote:

digicam
ETX-90 telescope
90mm aperture
1250mm focal length


Take the telescope to a store & try it on for size with various
digicams. What sort of f/stop would this be capable of?

Recently, I have become somewhat interested in trying to capture daytime
images of wildlife and landscapes.

Less to do with your equipment choice, but a good intro article for wildlife
photography none the less:
http://www.wildflorida.net/whenandwhere_article.html

--
Mark Lauter

Photos, Ideas & Opinions
http://www.marklauter.com

"paul" wrote in message
...
Ian Robelot wrote:

digicam
ETX-90 telescope
90mm aperture
1250mm focal length


Take the telescope to a store & try it on for size with various
digicams. What sort of f/stop would this be capable of?

The math says 1250/90+ f:13.8 mirror lens, so actual T:stop is closer to
f:16

"paul" wrote in message
...
Ian Robelot wrote:

digicam
ETX-90 telescope
90mm aperture
1250mm focal length


Take the telescope to a store & try it on for size with various
digicams. What sort of f/stop would this be capable of?

The math says 1250/90+ f:13.8 mirror lens, so actual T:stop is closer to
f:16

"Ian Robelot" wrote in message
.net...
Hello,

I originally posted this in the astro.amateur group as I am an amateur
astronomer, but am seeking opinions on the following:

Recently, I have become somewhat interested in trying to capture daytime
images of wildlife and landscapes. However, I am having difficulty
deciding
what direction to take. After browsing the archives of this group,
entering
the wildlife realm looks like it might be an expensive
proposition, but I have an idea and I wonder if it would work:

For astronomy, I have been using an ETX-90/ webcam combination for nearly
3
years now with success (for photo.digital group: The ETX-90 is a telescope
of the Maksutov-Cassegrain design with a 90mm aperture and 1250mm focal
length). Why couldn't I just afocally couple (this means to attach a
standard digital camera to the eyepiece of the telescope) a digicam to
the ETX-90 ota (optical tube assembly), with the combination mounted on a
tripod? If the digicam I
use has a zoom, I would have a range of magnification just like I would
with
a telephoto lens. Does anyone use a similar combination to image
wildlife?
I'd be interested in seeing your results, so share your website if
appropriate.
The problems that you will have with this telescope and any camera is that
the focal length is too long and that the out of focus highlights look like
doughnuts. Some people aren't bothered by this strange look, but most are.

You must be a very long way from the beast to get much of a shot. In
addition, the atmospheric heat waves wreak havoc with the images. So, if
you really want good wildlife shots, you should think of no longer that
600mm, and it should be a refractor.
Jim

In message ,
"Mark Lauter" wrote:

Recently, I have become somewhat interested in trying to capture daytime
images of wildlife and landscapes.

Less to do with your equipment choice, but a good intro article for wildlife
photography none the less:
http://www.wildflorida.net/whenandwhere_article.html

I don't shoot in Florida, but the idea translates well to New York. I
have taken most of my best bird photos in Central Park, in the heart of
NYC. The birds literally let me get up to 15x closer than I could get
in suburban or rural woods. I've been within 10 feet of herons and
egrets. In the suburbs, they will fly away as soon as they see me get
within 150 of them, most of the time.
--


John P Sheehy

Darrell wrote:

"paul" wrote in message
...

Ian Robelot wrote:

digicam
ETX-90 telescope
90mm aperture
1250mm focal length


Take the telescope to a store & try it on for size with various
digicams. What sort of f/stop would this be capable of?


The math says 1250/90+ f:13.8 mirror lens, so actual T:stop is closer to
f:16


Thanks I wasn't sure if that was the right way to calculate. I don't
know how you'd add on whatever the attached digicam starts at. Anyways I
guess this won't be a fast lens for moving wildlife at dusk.

Darrell wrote:

"paul" wrote in message
...

Ian Robelot wrote:

digicam
ETX-90 telescope
90mm aperture
1250mm focal length


Take the telescope to a store & try it on for size with various
digicams. What sort of f/stop would this be capable of?


The math says 1250/90+ f:13.8 mirror lens, so actual T:stop is closer to
f:16


Thanks I wasn't sure if that was the right way to calculate. I don't
know how you'd add on whatever the attached digicam starts at. Anyways I
guess this won't be a fast lens for moving wildlife at dusk.

Darrell wrote:

"paul" wrote in message
...

Ian Robelot wrote:

digicam
ETX-90 telescope
90mm aperture
1250mm focal length


Take the telescope to a store & try it on for size with various
digicams. What sort of f/stop would this be capable of?


The math says 1250/90+ f:13.8 mirror lens, so actual T:stop is closer to
f:16


Thanks I wasn't sure if that was the right way to calculate. I don't
know how you'd add on whatever the attached digicam starts at. Anyways I
guess this won't be a fast lens for moving wildlife at dusk.