Digital Rebel Disappointment

Dave wrote:
But learning and practice will be rewarded.

Learning and practice can be a reward in itself.

--
Joseph Meehan

Dia 's Muire duit

What exactly are you trying to photograph that the 400D can't handle?

wrote:
This is the last time I'll post about my absolute underwhelm-ment with
the 400D. I thought I'd think I died and went to heaven with this
camera. I've taken your comments about my "BUSY" problem and believe
I've gotten a handle on it, but I just feel so disappointed with this
item.

Last question: Am I incorrect in thinking that the 18-55mm lens gives
*less* depth of field than my beloved PowerShot A620? Do I have to buy
another $500 lens in order to get precise photographs (I mean without
suturing a tripod to my arm)?

Last question. Thanks.

On 6 Dec 2006 03:31:34 -0800, wrote:

This is the last time I'll post about my absolute underwhelm-ment with
the 400D. I thought I'd think I died and went to heaven with this
camera. I've taken your comments about my "BUSY" problem and believe
I've gotten a handle on it, but I just feel so disappointed with this
item.

Last question: Am I incorrect in thinking that the 18-55mm lens gives
*less* depth of field than my beloved PowerShot A620? Do I have to buy
another $500 lens in order to get precise photographs (I mean without
suturing a tripod to my arm)?

Last question. Thanks.

It sounds to me like you thought that by buying an expensive camera it
would come with the "Do What I Want" function built in.

Cheap cameras do what they want. Often what they want fits the
photographer's minimal needs. (Point and Shoot)

Expensive cameras do what you want. But you don't KNOW what you want.
You are blaming the camera for not being able to read your mind and
magically set itself to the right settings to produce the image you
want.

The solution to your problems is not a simple fix because it requires
that you learn a lot more about photography. Your question above
about depth-of-field shows that you don't understand that topic. So
you can't get the camera to do what you want. Does that make sense?

Take a photography course (or two, or three). Buy books on
photography. Find and use online tutorials. Learn how to use every
setting on your camera. Learn when and why and how you would change
each setting, use each focus mode, use each shooting mode, use each
metering mode, etc. Learn when and why you would want to use a small
f-stop number (large aperture, i.e. f4) or a large f-stop number
(small aperture, i.e. f16). Learn when and why you would want to use
a fast shutter (i.e. 1/800) or slow shutter (i.e. 1/10). Learn when
you would want to use Tv or Av or M modes. Learn when you want to
spot meter, when you want to average meter. Etc.

This camera is a great camera for a photographer who wants control
over their photos. If what you *really* want is to just point and
shoot, sell the 400D and get a powershot camera instead. My dad LOVES
the A450 my sister bought him for Father's day as a replacement for
his broken 350D. He never really wanted to do the learning and
fiddling necessary to get the benefits of the 350D, and really
appreciates the light weight of the A450 - he takes it with him
everywhere.

jc



--

"The nice thing about a mare is you get to ride a lot
of different horses without having to own that many."
~ Eileen Morgan of The Mare's Nest, PA

Kinon O'Cann wrote:
"acl" wrote in message
Well, only if you also use the same f-stop. As David Littleboy pointed
out, closing the aperture down will increase DOF to match the
smaller-sensor camera. And increasing ISO at the same time and by the same
amount will result in the same shutter speed and same noise.

I don't think so. If you have the same angle of view, so 35mm "equivilant,"
then the A620 will be somewhere around 7mm while the DSLR will be around
19mm. At the same aperture, how can a 19mm have the same depth of field as a
7mm lens?


As I said, there was a long and tedious thread about some time ago.

Briefly: You have a smaller f (by a factor A, where A the crop factor
bet the two cameras). This gives a larger DOF for the same f-stop. But
you can stop down so that you have the exact DOF. But then you have a
slower shutter speed. So youn increase the ISO to compensate. It's not
hard to show that you will get no worse noise (assuming only photon
noise) this way.


Maybe I should repeat it again: You will have to stop down to do this,
and increase ISO to keep the shutter speed constant. This is what I said
from the beginning.

"acl" wrote in message
...
Kinon O'Cann wrote:
wrote in message
ups.com...
This is the last time I'll post about my absolute underwhelm-ment with
the 400D. I thought I'd think I died and went to heaven with this
camera. I've taken your comments about my "BUSY" problem and believe
I've gotten a handle on it, but I just feel so disappointed with this
item.

Last question: Am I incorrect in thinking that the 18-55mm lens gives
*less* depth of field than my beloved PowerShot A620? Do I have to buy
another $500 lens in order to get precise photographs (I mean without
suturing a tripod to my arm)?

At the same angle of view, the A620 will have more depth of field due to
a much shorter focal length of the lens. Not your imagination.


Well, only if you also use the same f-stop. As David Littleboy pointed
out, closing the aperture down will increase DOF to match the
smaller-sensor camera. And increasing ISO at the same time and by the same
amount will result in the same shutter speed and same noise.

I don't think so. If you have the same angle of view, so 35mm "equivilant,"
then the A620 will be somewhere around 7mm while the DSLR will be around
19mm. At the same aperture, how can a 19mm have the same depth of field as a
7mm lens?


There was a long and tedious thread about this here some time ago.

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

"Kinon O'Cann" wrote:
wrote:

This is the last time I'll post about my absolute underwhelm-ment with
the 400D. I thought I'd think I died and went to heaven with this
camera. I've taken your comments about my "BUSY" problem and believe
I've gotten a handle on it, but I just feel so disappointed with this
item.

Last question: Am I incorrect in thinking that the 18-55mm lens gives
*less* depth of field than my beloved PowerShot A620? Do I have to buy
another $500 lens in order to get precise photographs (I mean without
suturing a tripod to my arm)?

At the same angle of view, the A620 will have more depth of field due to
a much shorter focal length of the lens. Not your imagination.

We've been through this before here recently, but...

(1) DOF increases as you stop down the lens. (Yes, I know you know that.)
(2) Diffraction limits sharpness if you stop down too much. (Yes, I know
you know that, too.)

But that means that if you have a sharpness requirement, then any camera
has a maximum DOF.

Are we OK so far?

Here's the punch line: that means that for cameras of the same pixel
count, _regardless of the format_, the maximum DOF is the same.

So the laws of optics and physics make it impossible for the A620 to have
"more DOF".

Isn't DOF also a function of the focal length of the lens, as well as the
aperture?


http://clarkvision.com/photoinfo/dof_myth/index.html

David J. Littleboy
Tokyo, Japan

acl wrote:
Kinon O'Cann wrote:
wrote in message
ups.com...
This is the last time I'll post about my absolute underwhelm-ment with
the 400D. I thought I'd think I died and went to heaven with this
camera. I've taken your comments about my "BUSY" problem and believe
I've gotten a handle on it, but I just feel so disappointed with this
item.

Last question: Am I incorrect in thinking that the 18-55mm lens gives
*less* depth of field than my beloved PowerShot A620? Do I have to buy
another $500 lens in order to get precise photographs (I mean without
suturing a tripod to my arm)?

At the same angle of view, the A620 will have more depth of field due
to a much shorter focal length of the lens. Not your imagination.


Well, only if you also use the same f-stop. As David Littleboy pointed
out, closing the aperture down will increase DOF to match the
smaller-sensor camera. And increasing ISO at the same time and by the
same amount will result in the same shutter speed and same noise.

There was a long and tedious thread about this here some time ago.

Several.

Don't forget, also, that a number of photographers enjoy limiting the
dof on purpose. One cannot do that well with a P+S.

--
John McWilliams

Robert Barr wrote:
What exactly are you trying to photograph that the 400D can't handle?

Note he said:

wrote:
This is the last time I'll post about my absolute underwhelm-ment with
the 400D.

We'll see, no??

--
lsmft

On Wed, 06 Dec 2006 12:26:56 -0500, Kinon O'Cann wrote:

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

"Kinon O'Cann" wrote:
wrote:

This is the last time I'll post about my absolute underwhelm-ment with
the 400D. I thought I'd think I died and went to heaven with this
camera. I've taken your comments about my "BUSY" problem and believe
I've gotten a handle on it, but I just feel so disappointed with this
item.

Last question: Am I incorrect in thinking that the 18-55mm lens gives
*less* depth of field than my beloved PowerShot A620? Do I have to buy
another $500 lens in order to get precise photographs (I mean without
suturing a tripod to my arm)?

At the same angle of view, the A620 will have more depth of field due to
a much shorter focal length of the lens. Not your imagination.

We've been through this before here recently, but...

(1) DOF increases as you stop down the lens. (Yes, I know you know that.)
(2) Diffraction limits sharpness if you stop down too much. (Yes, I know
you know that, too.)

But that means that if you have a sharpness requirement, then any camera
has a maximum DOF.

Are we OK so far?

Here's the punch line: that means that for cameras of the same pixel
count, _regardless of the format_, the maximum DOF is the same.

So the laws of optics and physics make it impossible for the A620 to have
"more DOF".

Isn't DOF also a function of the focal length of the lens, as well as the
aperture?

It's also a function of the resolution of the sensor.


http://clarkvision.com/photoinfo/dof_myth/index.html

David J. Littleboy
Tokyo, Japan




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

Kinon O'Cann wrote:

Isn't DOF also a function of the focal length of the lens, as well as the
aperture?

It depends how you look at it.

For a

50mm lens at f/16 on 24x36mm format
25mm lens at f/8 on 12x18mm format
12.5mm lens at f/4 on 6x9mm format

the dof is the same in all three cases.

If the larger formats have proportionately greater
sensitivity (generally true for digital cameras)
then the larger format is at no disadvantage since
you can use 1600 iso on the full frame DSLR instead
of 100 iso on the small format P&S.

Peter.
--