Best lens for wildlife photography?

On 2013.05.20 19:20 , PeterN wrote:
On 5/20/2013 1:08 PM, Alan Browne wrote:
On 2013.05.20 11:58 , M-M wrote:

And post-processing a poor exposure is not "easily fixed", in my
experience. Overexposed areas can not be compensated for, and
underexposed areas are often grainy.

Within a stop over or a couple under you can save a digital photo
however. Slide film? Faggetaboutit.

the word is pronounced furgedaboudit

Depends if you're in Boston, Brooklyn or The Bronx.

As to a hundred other places? Faggetaboutit.


--
"A Canadian is someone who knows how to have sex in a canoe."
-Pierre Berton

PeterN wrote:
On 5/20/2013 8:30 PM, Paul J Gans wrote:
PeterN wrote:
On 5/20/2013 1:08 PM, Alan Browne wrote:
On 2013.05.20 11:58 , M-M wrote:

And post-processing a poor exposure is not "easily fixed", in my
experience. Overexposed areas can not be compensated for, and
underexposed areas are often grainy.

Within a stop over or a couple under you can save a digital photo
however. Slide film? Faggetaboutit.

the word is pronounced furgedaboudit

Fuhgedaboudit.


You must be from either Bensonhoist, or Greenpernt. I loined it in
Flatbush.

Actually I was born in Cheekago, but I've lived in Noo Yawk
for the last 51 years, currently in Fort Greene.

What that means is that I shop at B&H and Adorama in poysen.

--
--- Paul J. Gans

That was a great detailed reply- I appreciate it and I hope others can
also.

But getting back to the OP, we were discussing wildlife photography
(where a flash would be useless), and the best (long) lens to use. Wally
said to use a tele-extender or just crop it. My point was that these can
not take the place of glass and aperture.

Sure, if the subject is in the center of the frame and you have a good
enough sensor, you can crop with little consequence as you suggest, and
I agree.

I once read that there is but one use for digital zoom, and that is to
get a better exposure than by cropping. I have tried it and it is true.
Take a photo and enlarge it 2X. Then take the same photo at 2X digital
zoom. The result is the same except the one taken with digital zoom is
very likely to be better exposed.

(Incidentally, I have found one more use for digital zoom and that is to
aid in manual focus. It comes in handy for astrophotography. But that is
another subject.)

Also, to the poster who suggested that the difference might be only one
or maybe 2 stops- I believe todays cameras work in fractions of f-stops.
Correct me if I am wrong, but it is no longer just 1/125, 1/60, 1/30,
1/15... but there are many stops in between and the same with the
aperture.


--
m-m
Photo Gallery:
http://www.mhmyers.com




In article ,
Wolfgang Weisselberg wrote:

M-M wrote:
In article ,
Wolfgang Weisselberg wrote:

An uncropped photo is exposed for the frame. When you crop out a
portion, the exposure is likely to be off.

You're not talking sense in either sentence.

I'll try to rephrase it.

That won't help.

When a camera auto-exposes a photo, it takes the entire frame into
account. If you crop out a portion, it would not be the same exposure as
if you zoomed in on that portion and exposed for it.

What you're saying sounds reasonable, but is wrong.


At least _I_ understand what I'm saying.

I didn't say I didn't understand you ...

Let's start with "An uncropped photo is exposed for the frame."
This is obviously easily wrong if one uses the M(aster) mode
(including manual ISO) --- maybe with test shots, maybe with
guessing, maybe with a handheld meter.

This can also be argued wrong if you use a significant amount
of light from flash --- there you underexpose (the ambient
light) and set the flash (in conjunction with the aperture
and flash-object distance) to the right value. ETTL (version
I) was tied too tightly to the focus point(s) used --- it
basically ignored much of the rest of the frame. With direct
flash and a lens reporting the distance ETTL I and II would
set the flash power according to the distance and aperture and
mostly ignore the returning light of the measuring flash ---
basically, ignoring most of the frame again.


Let's go on to "When a camera auto-exposes a photo, it takes
the entire frame into account". Please look up partial and
spot metering. Only the centre is being used (smaller if
spot, larger if partial, at least with Canon), the rest of
the frame doesn't even count.

Further, even with centre weighted average mode the border
counts for very little, so framing the image such that
it's border is reduced often causes very little change ---
not enough to be relevant and often not enough to choose
a different amount of light to fall on the sensor (i.e. an
equivalent ISO/exposure/aperture triple).


Worse, with matrix the camera decides where to use and where
to ignore the frame's brightness, and in fact can detect
"it's sunshine outside" from a comparatively small part of
the frame and then may use a "sunny 16" or "sunny 8" rule, no
matter what the rest of the frame is. (Of course it can also
detect backlit subjects and then make them be exposed right,
not the larger backlit area. So a change in framing may or
may not have the same amount of light on the sensor.


So: no, the camera does *not* take the entire frame into
account in most cases.


Let's look at "If you crop out a portion, it would not be the
same exposure as if you zoomed in on that portion and exposed
for it." Now, the obvious counter example is the evenly lit
brick wall filling the frame. Zoom in and the exposure stays
the same. OK, you said "the exposure is likely to be off",
not "always off".

Now, see above: with M(aster) mode, assuming you know what
you do, and with spot and partial mode (again assuming you know
what you do) the exposure on the main subjects will be right
--- even if you crop severely and let only those subjects in.
With center weighted average mode, cutting off the borders
doesn't make an appreciable different --- you'd have to
cut much and that much needs to be either very dark or very
bright compared to the rest of the image to make a difference.
With matrix it only matters if the camera thinks the zoomed
in frame means a different subject or switches from/to backlit
subject mode or does/does not switch to "full sunlight" mode.

In short: if you don't crop lots, even with full auto exposure
settings the esposure is likely to be right for the cropped
image. If you intend to crop much and don't trust the matrix
mode, M or spot or partial mode will see you through.


In fact, some cameras have/had other metering moded: average
(not centre weighted), in which case the whole frame would be
important, or multi-spot, or they replace the 'centre
weighted average' with a 'active focus point weighted average',
on the general idea you probably want that what you focus on
to be important in the image.

-Wolfgang

In article
,
M-M wrote:

I once read that there is but one use for digital zoom, and that is to
get a better exposure than by cropping. I have tried it and it is true.
Take a photo and enlarge it 2X. Then take the same photo at 2X digital
zoom. The result is the same except the one taken with digital zoom is
very likely to be better exposed.

it's very likely that any difference will be completely insignificant,
if there's any difference at all.

(Incidentally, I have found one more use for digital zoom and that is to
aid in manual focus. It comes in handy for astrophotography. But that is
another subject.)

Also, to the poster who suggested that the difference might be only one
or maybe 2 stops- I believe todays cameras work in fractions of f-stops.
Correct me if I am wrong, but it is no longer just 1/125, 1/60, 1/30,
1/15... but there are many stops in between and the same with the
aperture.

the difference is likely to be under 1 stop, probably under 1/2 stop.

and yes, cameras can shoot at any shutter speed, f/stop and iso
combination you want. that's been the case for *years*.

M-M wrote:
That was a great detailed reply- I appreciate it and I hope others can
also.

Please don't top post and add the full quote to the bottom.
Intersperse your comments with the original text, shortening
where appropriate and possibly indicating it by '[...]' or
'[... describes his holiday ...]' instead of quoting big chunks
(in this example a detailed report about his holiday yadda
yadda yadda) you're not answering to.


But getting back to the OP, we were discussing wildlife photography
(where a flash would be useless),

Again wrong.

The only way you can freeze or half-freeze a humming bird's
wings in flight is using flash. Normal compact flash on low
power settings (higher power settings mean a longer flash
duration!) or you could use special high speed flashes.

You could also google for "better beamer". It's a tool
sometimes used for wildlife, even if the flash only lifts
the shadows.

and the best (long) lens to use. Wally
said to use a tele-extender or just crop it. My point was that these can
not take the place of glass and aperture.

Of course, I'd say "buy the 1200mm f/5.6 if you need the
range", but they're really rare and you can expect prices
above 100,000 USD. Since selling one's children into slavery
is illegal *and* doesn't fetch that much money ...

.... you might either rob a couple banks and spend 25 years in
prison or make do with a somewhat shorter lens. Looking at
http://www.usa.canon.com/cusa/consum...ef_lens_lineup
the cheapest long lens would be the EF 400mm f/5.6L USM
(which needs a high end body to focus with a 1.4x TC at an
effective f/8) or the EF 300mm f/4L IS USM + an 1.4x TC.

Anything faster or longer gets really expensive really fast.
(And remember you have to carry the weight with you, which
may be a pretty hard limtation.) So a TC, especially if you
do have fast glass that can take it, can be a good compromise.

Sure, if the subject is in the center of the frame and you have a good
enough sensor, you can crop with little consequence as you suggest, and
I agree.

? I suggested that you prefer a TC over cropping.


I once read that there is but one use for digital zoom, and that is to
get a better exposure than by cropping. I have tried it and it is true.

See previous post why this is wrong, at least when the
photographer knows what he is doing.

Additionally, there is a 41 MPix mobile phone --- here "digital
zoom" actually means "do not scale down as much, crop more
of the border instead", as they don't output 41 MPix photos.
Other cameras act similarly when using reduced pixel count
output at the tele end.

Take a photo and enlarge it 2X. Then take the same photo at 2X digital
zoom. The result is the same except the one taken with digital zoom is
very likely to be better exposed.

See previous post why s/likely/rarely/, unless you're
shooting edge cases and don't know how to properly use your
camera.

(Incidentally, I have found one more use for digital zoom and that is to
aid in manual focus. It comes in handy for astrophotography. But that is
another subject.)

Incidentally, for that you use lifeview and the focussing
loupe button.


Also, to the poster who suggested that the difference might be only one
or maybe 2 stops- I believe todays cameras work in fractions of f-stops.
Correct me if I am wrong, but it is no longer just 1/125, 1/60, 1/30,
1/15... but there are many stops in between and the same with the
aperture.

You can switch many cameras to full, 1/2 or 1/3rd stops.
That's zero, 1 or 2 settings between 1/125 and 1/60.

-Wolfgang

"Wolfgang Weisselberg" wrote in message
...

M-M wrote:
That was a great detailed reply- I appreciate it and I hope others can
also.

snip

Of course, I'd say "buy the 1200mm f/5.6 if you need the
range", but they're really rare and you can expect prices
above 100,000 USD. Since selling one's children into slavery
is illegal *and* doesn't fetch that much money ...

++++++
And then there is the cost of a tripod and head capable of holding the lens.
Also the cost of hiring two men and a strong boy to carry it all around for
you! ;-)
Ron
++++++

snip

Ron wrote:
"Wolfgang Weisselberg" wrote in message

Of course, I'd say "buy the 1200mm f/5.6 if you need the
range", but they're really rare and you can expect prices
above 100,000 USD. Since selling one's children into slavery
is illegal *and* doesn't fetch that much money ...

++++++
And then there is the cost of a tripod and head capable of holding the lens.
Also the cost of hiring two men and a strong boy to carry it all around for
you! ;-)
++++++

That's like saying "I buy a learjet and then the cost of
supplying the on-board bar with a bottle of cheap champagne
or two for all the cross-atlantic flights is something one
must not forget to factor in."

-Wolfgang