What Is the Name For "Perspective" in Digital Photography?

Hello. I'm going to change my screen name to AsTheCameraTurns. I
bought a Canon PowerShot A620 two weeks ago, took it back after you
guys told me it was no good for depth of field, bought a Kodak Z650,
took that back because it got bad reviews from DPREVIEW, then finally
('cause Adorama, NYC, was offering the Canon PowerShot for $50 less
than I paid in my superstore) bought the Canon PowerShot A620 again.

Obviously it has no kind of image stabilization, but my sister told me
that our Dad, a M.F.A. grad, said once that all claims of image
stabilization are fool's gold; use a tripod.

Well, I tried taking some photos "manually." The PowerShot just WILL
NOT SHOOT when it decides it doesn't want to, which I suppose means
when it decides the moron manning it has the dt's. So I set it on our
deck rail and just shot randomly at a very baroque evening forest.
VERY high contrast between the bright setting sun and the green leaves.


Well, the depth of field in some pictures it decided to take is good,
particularly if there's some large object in the frame (like a tree
trunk); but the depth of field (or what *I* call depth of field) in
far-off leaves is very flat. So is this what you guys meant when you
said a 4X optical zoom wouldn't give me good focal length?

In article .com,
"Jules Vide" wrote:

Hello. I'm going to change my screen name to AsTheCameraTurns. I
bought a Canon PowerShot A620 two weeks ago, took it back after you
guys told me it was no good for depth of field, bought a Kodak Z650,
took that back because it got bad reviews from DPREVIEW, then finally
('cause Adorama, NYC, was offering the Canon PowerShot for $50 less
than I paid in my superstore) bought the Canon PowerShot A620 again.

Obviously it has no kind of image stabilization, but my sister told me
that our Dad, a M.F.A. grad, said once that all claims of image
stabilization are fool's gold; use a tripod.

Well, I tried taking some photos "manually." The PowerShot just WILL
NOT SHOOT when it decides it doesn't want to, which I suppose means
when it decides the moron manning it has the dt's. So I set it on our
deck rail and just shot randomly at a very baroque evening forest.
VERY high contrast between the bright setting sun and the green leaves.


Well, the depth of field in some pictures it decided to take is good,
particularly if there's some large object in the frame (like a tree
trunk); but the depth of field (or what *I* call depth of field) in
far-off leaves is very flat. So is this what you guys meant when you
said a 4X optical zoom wouldn't give me good focal length?

Have you actually read the manual?

Jules Vide wrote:

What Is the Name For "Perspective" in Digital Photography?

It's still called perspective.

Obviously it has no kind of image stabilization, but my sister told me
that our Dad, a M.F.A. grad, said once that all claims of image
stabilization are fool's gold; use a tripod.

Ever try and use a tripod on horseback? On a small boat?
In a museum that bans tripods? In a park in Paris without
a permit? (you'll be called a professional and you must get a permit)
From an airplane?

So your hiking down a trail, turn a corner and a bear is there
in the middle of the trail. Do you:

1) Take you pack off, set the pack down, and lean over
to get out your tripod, mount the camera
and take the picture as the bear charges at you
after you bent over?

2) Take a quick snapshot with your image stabilized camera
that was hanging around your neck while you are slowly
backing up?

2A) Take a flash picture as the bear is about to pounce on
you so people will know how you died.
The bear gets startled by the flash and runs off (true
story reported in Popular Photography a few years ago).

3) Fall to a fetal position, play dead and hope?
(hint: if it is a black bear, this one might get you killed.)

;-)

Roger

Jules Vide wrote:

Hello. I'm going to change my screen name to AsTheCameraTurns. I
bought a Canon PowerShot A620 two weeks ago, took it back after you
guys told me it was no good for depth of field, bought a Kodak Z650,
took that back because it got bad reviews from DPREVIEW, then finally
('cause Adorama, NYC, was offering the Canon PowerShot for $50 less
than I paid in my superstore) bought the Canon PowerShot A620 again.

Uh, no point and shoot is "good for depth of field" or all point-and-shoots
are "good for depth of field" depending on whether you want a little of it
or a lot of it. Changing brands unless you go to a superzoom which at long
focal length and short range gives you a reasonably low depth of field and
gives the same high one as other point and shoots under other conditions
isn't going to make much difference.

Obviously it has no kind of image stabilization, but my sister told me
that our Dad, a M.F.A. grad, said once that all claims of image
stabilization are fool's gold; use a tripod.

That's good advice for stationary subjects, but it's kind of hard to use a
tripod to track a basketball game. IS works. It's not a substitute for a
tripod, but it does work.

Well, I tried taking some photos "manually." The PowerShot just WILL
NOT SHOOT when it decides it doesn't want to, which I suppose means
when it decides the moron manning it has the dt's.

If it has no IS then it has no way of knowing that it's moving. More likely
it isn't getting focus lock.

So I set it on our
deck rail and just shot randomly at a very baroque evening forest.
VERY high contrast between the bright setting sun and the green leaves.


Well, the depth of field in some pictures it decided to take is good,
particularly if there's some large object in the frame (like a tree
trunk); but the depth of field (or what *I* call depth of field) in
far-off leaves is very flat. So is this what you guys meant when you
said a 4X optical zoom wouldn't give me good focal length?

Depth of field isn't "flat" or "not flat". If everything from close to the
camera on out is sharp then you have wide depth of field, if everything at
a certain distance is sharp but things slightly closer or slightly farther
away are not then you have a narrow depth of field.



--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

On 13 Jul 2006 16:19:04 -0700, Jules Vide wrote:
Obviously it has no kind of image stabilization, but my sister told me
that our Dad, a M.F.A. grad, said once that all claims of image
stabilization are fool's gold; use a tripod.

http://home.uchicago.edu/~dmsilev/dart_stab.jpg
http://home.uchicago.edu/~dmsilev/dart_normal.jpg

Two shots, taken in the same way except that the first had the
stabilizer turned on, and the second had the stabilizer off. The
difference in sharpness is pretty clear.

The stabilizer means that you can take pictures at slower shutter speeds
without needing a tripod. Of course, they have their limmits; a 1 second
shot will certainly need a tripod.

Picture info: 432 mm equivalent, 1/15s, f/3.3, no flash. The posted
images are 100% crops from the original. Panasonic FZ5, using stabilizer
Mode 2 for the first image, stabilizer off for the second.

-dms

Jules Vide wrote:
Hello. I'm going to change my screen name to AsTheCameraTurns. I
bought a Canon PowerShot A620 two weeks ago, took it back ..
bought a Kodak Z650,
took that back
bought the Canon PowerShot A620 again.


I vote this one as our weekly troll.

--
Joseph Meehan

Dia duit

David J. Littleboy wrote:


"J. Clarke" wrote:

Uh, no point and shoot is "good for depth of field" or all
point-and-shoots
are "good for depth of field" depending on whether you want a little of
it or a lot of it.

It turns out that _for the same noise level and same pixel count_, there's
absolutely no difference between a 6MP 4x5 sensor (with golf-ball-size
pixels) and the tiniest 6MP dcam in the _maximum achievable DOF_.

It turns out that diffraction (which limits how far you can stop down to
increase the DOF) scales with sensor size, so that a larger format camera
(for the same target resolution) can be stopped down much further without
reducing sharpness.

Furthermore, sensitivity scales in the same way, so while you need a much
smaller aperture on the 4x5 camera, you get the same shutter speed at a
far higher ISO (a higher ISO that gives the same signal to noise ratio as
the P&S dcam).

Of course, the minimum DOF is much smaller with larger format cameras.

You _do_ like to argue from theory rather than practice, don't you.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

"J. Clarke" wrote in message
...
David J. Littleboy wrote:


"J. Clarke" wrote:

Uh, no point and shoot is "good for depth of field" or all
point-and-shoots
are "good for depth of field" depending on whether you want a little of
it or a lot of it.

It turns out that _for the same noise level and same pixel count_,
there's
absolutely no difference between a 6MP 4x5 sensor (with golf-ball-size
pixels) and the tiniest 6MP dcam in the _maximum achievable DOF_.

It turns out that diffraction (which limits how far you can stop down to
increase the DOF) scales with sensor size, so that a larger format camera
(for the same target resolution) can be stopped down much further without
reducing sharpness.

Furthermore, sensitivity scales in the same way, so while you need a much
smaller aperture on the 4x5 camera, you get the same shutter speed at a
far higher ISO (a higher ISO that gives the same signal to noise ratio as
the P&S dcam).

Of course, the minimum DOF is much smaller with larger format cameras.

You _do_ like to argue from theory rather than practice, don't you.

Yes, but this works in practice; f/16 on the 5D at ISO 800 will look very
much like f/5.6 at ISO 100 on a P&S dcam in terms of both DOF and shutter
speed. And current P&S dcams are seeing more damage from diffraction at
f/5.6 than the 5D does at f/16.

David J. Littleboy
Tokyo, Japan

Roger N. Clark (change username to rnclark) wrote:
Jules Vide wrote:

What Is the Name For "Perspective" in Digital Photography?

It's still called perspective.

Obviously it has no kind of image stabilization, but my sister told me
that our Dad, a M.F.A. grad, said once that all claims of image
stabilization are fool's gold; use a tripod.

Ever try and use a tripod on horseback? On a small boat?
In a museum that bans tripods? In a park in Paris without
a permit? (you'll be called a professional and you must get a permit)
From an airplane?

So your hiking down a trail, turn a corner and a bear is there
in the middle of the trail. Do you:

1) Take you pack off, set the pack down, and lean over
to get out your tripod, mount the camera
and take the picture as the bear charges at you
after you bent over?

2) Take a quick snapshot with your image stabilized camera
that was hanging around your neck while you are slowly
backing up?

2A) Take a flash picture as the bear is about to pounce on
you so people will know how you died.
The bear gets startled by the flash and runs off (true
story reported in Popular Photography a few years ago).

3) Fall to a fetal position, play dead and hope?
(hint: if it is a black bear, this one might get you killed.)

;-)

Roger

Number 3, without a doubt, probably because I fainted. In any case,
your chances of survival aren't all that good.

Ron Hunter wrote:
: Roger N. Clark (change username to rnclark) wrote:
:
: So your hiking down a trail, turn a corner and a bear is there
: in the middle of the trail. Do you:
:
: 3) Fall to a fetal position, play dead and hope?
: (hint: if it is a black bear, this one might get you killed.)
:
: ;-)

Reminds me of the old joke my cousin (a former National Park Ranger) told
me. How do you tell the difference between a black bear and a grizzly
bear? Slap it and climb a tree. If it comes up after you, its a black
bear. If it shakes you down, its a grizzly.

To the prior point, counting on IS to completely replace a tripod is a bad
idea. Just as bad is to count on a tripod to be as effective or useable in
all situations as IS. Depending on the user and the types of photographs
the photographer is looking to take, IS may be more useful to some people
than others. Also it is one more "gadget" that may confuse those who are
easily overwhelmed. And it could conceivably add to the "button press to
image capture" delay that many find upsetting. That last will depend on
how the IS is implemented. Having no direct evidence I can't say for sure.
But if the IS is physically implemented after the auto focus, it COULD
make the delay worse. IMHO. On the other hand, as mentioned (with tongue
in cheek) above, in some situations IS is definately the best, or only,
way to go.

Randy

==========
Randy Berbaum
Champaign, IL