Wildlife photogs need to go beyond camera lenses

I've seen quite a few shots of animals recently where the photogs
coudn't get too close, for various reasons. What struck me was that
although the shots were sharp, they were obviously heavily cropped
because noise was evident in them. Noise in pro DSLRs is "attractive"
in a film-like way, but the cropping still reduces the overall quality
of the image. If a photog is using a 600mm lens with a converter to
get 1200mm, and it's still not enough to avoid heavy cropping, maybe
it's time to get away from long refractive telephotos and into reflex
systems that would allow much greater focal lengths while maintaining
a reasonable focal ratio? The only drawback of course would be the
inability to stop-down and the attendent short depth of field. But,
there are lens systems out there that can provide focal lengths in the
2500mm range with f6.3 focal ratios. No autofocus though.
-Rich

In message ,
Rich wrote:

I've seen quite a few shots of animals recently where the photogs
coudn't get too close, for various reasons. What struck me was that
although the shots were sharp, they were obviously heavily cropped
because noise was evident in them. Noise in pro DSLRs is "attractive"
in a film-like way, but the cropping still reduces the overall quality
of the image. If a photog is using a 600mm lens with a converter to
get 1200mm, and it's still not enough to avoid heavy cropping, maybe
it's time to get away from long refractive telephotos and into reflex
systems that would allow much greater focal lengths while maintaining
a reasonable focal ratio? The only drawback of course would be the
inability to stop-down and the attendent short depth of field. But,
there are lens systems out there that can provide focal lengths in the
2500mm range with f6.3 focal ratios. No autofocus though.

Might work for a bird on a wire, or in the sky, but the bokeh would be a
mess for an animal in the brush or in a tree.
--


John P Sheehy

Ed Ruf wrote:

On Sat, 10 Sep 2005 22:12:52 -0400, in rec.photo.digital.slr-systems Rich
The only drawback of course would be the
inability to stop-down and the attendent short depth of field. But,
there are lens systems out there that can provide focal lengths in the
2500mm range with f6.3 focal ratios. No autofocus though.

And the brokeh looks like what?


Ugly beyond words?

I own one mirror lens and it's such a PITA to use and produces such UGLY
bokeh, the only thing it can even be used for is maybe a bird or something
in water or in the sky.
--

Stacey

"Stacey" wrote in message
...
Ed Ruf wrote:

On Sat, 10 Sep 2005 22:12:52 -0400, in rec.photo.digital.slr-systems
Rich
The only drawback of course would be the
inability to stop-down and the attendent short depth of field. But,
there are lens systems out there that can provide focal lengths in the
2500mm range with f6.3 focal ratios. No autofocus though.

And the brokeh looks like what?


Ugly beyond words?

I own one mirror lens and it's such a PITA to use and produces such UGLY
bokeh, the only thing it can even be used for is maybe a bird or something
in water or in the sky.


Some folks like it, some folks don't.
http://mendosus.com/jpg/gumnuts.jpg
Some folks don't care either way.

This example is a particularly *aggressive* one.

--
Jeff R.

Rich wrote:
If a photog is using a 600mm lens with a converter to
get 1200mm, and it's still not enough to avoid heavy cropping, maybe
it's time to get away from long refractive telephotos and into reflex
systems that would allow much greater focal lengths while maintaining
a reasonable focal ratio?

Or to resort to digiscoping. More of a hassle, but much better images
when you get it right.

http://www.shortcourses.com/how/digi...igiscoping.htm

Jan B=F6hme

On Sun, 11 Sep 2005 03:27:01 GMT, wrote:

In message ,
Rich wrote:

I've seen quite a few shots of animals recently where the photogs
coudn't get too close, for various reasons. What struck me was that
although the shots were sharp, they were obviously heavily cropped
because noise was evident in them. Noise in pro DSLRs is "attractive"
in a film-like way, but the cropping still reduces the overall quality
of the image. If a photog is using a 600mm lens with a converter to
get 1200mm, and it's still not enough to avoid heavy cropping, maybe
it's time to get away from long refractive telephotos and into reflex
systems that would allow much greater focal lengths while maintaining
a reasonable focal ratio? The only drawback of course would be the
inability to stop-down and the attendent short depth of field. But,
there are lens systems out there that can provide focal lengths in the
2500mm range with f6.3 focal ratios. No autofocus though.

Might work for a bird on a wire, or in the sky, but the bokeh would be a
mess for an animal in the brush or in a tree.

There is no way around the blurred "donuts" unfortunately.
-Rich

On Sat, 10 Sep 2005 23:27:54 -0400, Ed Ruf
wrote:

On Sat, 10 Sep 2005 22:12:52 -0400, in rec.photo.digital.slr-systems Rich
wrote:

I've seen quite a few shots of animals recently where the photogs
coudn't get too close, for various reasons. What struck me was that
although the shots were sharp, they were obviously heavily cropped
because noise was evident in them. Noise in pro DSLRs is "attractive"
in a film-like way, but the cropping still reduces the overall quality
of the image. If a photog is using a 600mm lens with a converter to
get 1200mm, and it's still not enough to avoid heavy cropping, maybe
it's time to get away from long refractive telephotos and into reflex
systems that would allow much greater focal lengths while maintaining
a reasonable focal ratio? The only drawback of course would be the
inability to stop-down and the attendent short depth of field. But,
there are lens systems out there that can provide focal lengths in the
2500mm range with f6.3 focal ratios. No autofocus though.

And the brokeh looks like what?

Maybe we could learn to like the christmas tree-like defocussed circle
of light?
If the idea is to capture the animal (or whatever) in the best detail
possible, and not to make artistic pictures, it wouldn't matter about
the background.
-Rich

On Sun, 11 Sep 2005 18:09:19 +1000, "Jeff R"
wrote:


"Stacey" wrote in message
...
Ed Ruf wrote:

On Sat, 10 Sep 2005 22:12:52 -0400, in rec.photo.digital.slr-systems
Rich
The only drawback of course would be the
inability to stop-down and the attendent short depth of field. But,
there are lens systems out there that can provide focal lengths in the
2500mm range with f6.3 focal ratios. No autofocus though.

And the brokeh looks like what?


Ugly beyond words?

I own one mirror lens and it's such a PITA to use and produces such UGLY
bokeh, the only thing it can even be used for is maybe a bird or something
in water or in the sky.


Some folks like it, some folks don't.
http://mendosus.com/jpg/gumnuts.jpg
Some folks don't care either way.

This example is a particularly *aggressive* one.

That, I admit is pretty horrible. It's a good example of why
refractive elements still dominate the field. But some pictures
(say a lion on the Savannah) won't produce that kind of effect since
specular highlights on the high grass likely won't happen, or will be
so subdued that they won't produce that kind of effect.
-Rich

On 11 Sep 2005 10:22:43 -0700, "Jan Böhme" wrote:


Rich wrote:
If a photog is using a 600mm lens with a converter to
get 1200mm, and it's still not enough to avoid heavy cropping, maybe
it's time to get away from long refractive telephotos and into reflex
systems that would allow much greater focal lengths while maintaining
a reasonable focal ratio?

Or to resort to digiscoping. More of a hassle, but much better images
when you get it right.

http://www.shortcourses.com/how/digi...igiscoping.htm

Jan Böhme

Main problem is speed. I've seen the calculations and when using (for
example) and 80mm scope to produce a 2000mm focal length, you're
f-ratio becomes 25. Better to invest in a good quality telescope of
sufficient aperture and a high quality projection lens (eyepiece)
to capture the image. P&S shooters have no choice in this, they have
to use an eyepiece to get an image owing to the fact their camera
lenses are fixed. Here's a shot I took at 4000mm using a telescope
with a 125mm wide front aperture. F-ratio was (4000/125) 32.

http://www.pbase.com/andersonrm/image/46946057

Because the lens was an f-8 achromat, and not an apochromat, there is
minor residual chromatic aberration, which could be removed in
software. The scope itself has a focal length of 1000mm and is about
4 feet long. But I cobbled it together as a hobby project for around
$300.00, including it's tripod so it's an inexpensive way of getting
focal length.
-Rich

Rich wrote:
On 11 Sep 2005 10:22:43 -0700, "Jan B=F6hme" wrote:

digiscoping.

Main problem is speed. I've seen the calculations and when using (for
example) and 80mm scope to produce a 2000mm focal length, you're
f-ratio becomes 25.

Not something for dawn or dusk, agreed. But I have a friend who does
digiscoping with a Swarovski ATS-80 HD vith a 20x eyepiece, a
digiscoping adapter, and a Nikon CP 995. (He used to borrow my Coolpix,
that's how I got into it.) He can get decent pics at full zoom, which
would have a focal equivalent of just over 3000 mm, and an f-ratio of
just under 40, according to your calculations, also when the bird isn't
in bright sunlight.

P&S shooters have no choice in this, they have
to use an eyepiece to get an image owing to the fact their camera
lenses are fixed. Here's a shot I took at 4000mm using a telescope
with a 125mm wide front aperture. F-ratio was (4000/125) 32.

I agree that the extra three stops of ISO sensitivity you get in a DSLR
must be very useful when shooting through a telescope, and there are
cheap adapters that allow a DSLR to me coupled to a telescope. OTOH,
then you can't use the camera lens of the digicam for extra zoom. Given
the same scope, you get a lot more of both light and sensitivity, but
considerably less equivalent focal length.

In theory, it should be possible to hook up a DSLR, lens and all,
behind a telescope, just as the P&S shooters do with their digicams.
Then, one would take advantage of the three extra stops of sensitivity,
without having to compromise on equivalent focal length.

But I have never seen it done. And nomal lens diameters of SLR lenses
aren't exactly ideal for digiscoping purposes.

Jan B=F6hme