On 2009-02-05 20:05:27 -0800, Pat said:

On Feb 5, 11:36*am, C J Campbell
wrote:
On 2009-02-04 15:39:05 -0800, Pat said:



On Feb 4, 5:27*pm, C J Campbell
wrote:
On 2009-02-04 10:59:04 -0800, Pat said
:

On Feb 3, 3:35*am, (Ray Fischer) wrote:
Mr.T MrT@home wrote:
"Sir John Howard" wrote in message
This is fine if you want to reduce depth of field. However, a til
t/
s
hift
lens is often used to increase depth of field. You cannot do that
i
n
Photoshop with a single image.

A tilt/shift lens is primary used to correct perspective. A lens a
pe
rt
ure
controls depth of field.

Partly true, a simple tilt-shift lens is not a complete substitute
fo
r a
full view camera with tilting film back and lensboard which DO allo
w
the
depth of field to be non parallel to the film/image plane.
And you cannot do that with lens aperture alone.

I've taken photos that had subjects from six inches to infinity, and
even at f22 it's hard to get everything to be sharp. *Of course, T
S
lenses tend to be too expensive for the occasional need.

--
Ray Fischer * * * *
*

There is software to handle the extended depth of field. *You take
a
series of pictures and merge them. *Say you start by focusing 6 inc
he
s
out. *Then if your DOF ends at 12", you take another picture and fo
cu
s
8 inches out. *If your DOF then ends at 16", your next picture is a
t
12" or so. *You then merge the photos together and get one picture
with extended DOF. *I've never used the software but I've read
articles about it and it's pretty slick (and easy).

It is the same concept of bracketing exposures and blending the image
s
to give a larger dynamic range.

Sure, but it is not always possible to take multiple exposures so that
you can merge them together.

After all, you can take two exposures and effectively double the pixel
s
in your camera, too. So why bother getting a 24 megapixel camera when
you can get nearly the same resolution with two 12 megapixel exposures
?
Maybe the bride won't sit still?

--
Waddling Eagle
World Famous Flight Instructor

Actually, if you took 10 images where you did nothing except changed
the focus and you merge them together, you'd still have your original
resolution. *You wouldn't be gaining any information, you'd just be
making sure that all of it was in focus.

I said nothing about changing focus.

As for gaining information, perhaps if you moved the camera to the left
a half a pixel for the second shot. :-)

--
Waddling Eagle
World Famous Flight Instructor

I don't think you understood my 1st post re multiple exposures. You
take multiple exposures but don't move the camera -- just move the
focal point. That, obviously, changes what's in focus. My merging
the photos in much same way you would merge photos for a high-dynamic-
range photo; you can get a photo with a huge depth of field (which is
what the thread was about). It was not about merging to make a
panoramic or something.

No, Pat. We all know about this technique. I use it most often in macro shots.



--
Waddling Eagle
World Famous Flight Instructor