On Wed, 25 Apr 2018 05:46:13 -0400, nospam
wrote:

In article , Eric Stevens
wrote:


We are talking about camera adjustments, remember?

which takes more than a few seconds. movements are not automatic.

Either you have never used such a camera or you didn't know what you
were doing.

i have long ago, and i do.

let's not forget that you incorrectly claimed that to photograph a
'tall wall' would require tilting the *rear* standard, which is wrong.

That's the problem with your surreptitious snips. You haven't quoted
me correctly.

i know exactly what you wrote.

I originally wrote:

"There are some things which as far as I know can't be done with
digital.

then you know wrong.

Consider photographing a very tall wall from close up
while keeping the whole image in focus. A technical camera copes
with this by raising and tilting the lens upwards while tilting the
camera back".

as i said, the camera back is *not* tilted for a tall wall, or more
commonly a tall building because walls are boring, however, the math is
the same.

Let's say it is the front of a 1000 year old building: and you have
limited room: and you want to have all of the wall in the best
possible focus. It's interesting and just making do with hyperfocal
distance is not good enough. You *have* to use a camera setup that
employs the same basic geometry of
https://upload.wikimedia.org/wikiped...cheimpflug.jpg
(except that the assembly is pointing up rather than down).
Alternatively, tilt the diagram 90 degrees anticlockwise.r

the front standard (i.e., lens) is raised:
https://static1.squarespace.com/stat...f5b4b9/t/576c2
e495a655be13f013ab2/1467902630687/rise.gif

If you are going to keep the whole of the wall in focus the plane of
the wall, the plane of the lens and the film plane must have a common
point of intersection. The lens will have to be raised and tilted
back. The film plane will have to be tilted back more.
to the rear.

https://upload.wikimedia.org/wikiped...cheimpflug.jpg
is a diagram from a related case, where the photographer wants to keep
the ground in focus. I don't know of a digital camera which will do
quite that.

that's not relevant for the situation you described.

So you say. That's the very point I have been trying to describe.

here's a situation where it would be, and note the rear standard is
*parallel* to the building:
https://static1.squarespace.com/static/576bd0f715d5dbd3def5b4b9/t/576c2e495a655be13f013aba/1467902699499/Scheimpflug.gif

I've seen that before but I don't think it qualifies as "photographing
a very tall wall from close up" as I originally specified.
--

Regards,

Eric Stevens