27 May
2007
27 May
'07
3:20 a.m.
On Sun, 27 May 2007 00:28:11 +0100 (BST)
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
The right way to get better depth of field for oblique
shots is to
tilt the lens (!). There's a well known principle, the name of which
I can neither spell nor pronounce
Scheimpflug. There are also special shift and
tilt lenses for (D)SLR
cameras. Some bellows and extension tubes have shift / tilt fuctions for
macro as well. So you can shift / tilt with any lens using this macro
extension tubes.
Yes, there are
digital backs for them, but you want to sit down before hearing the
price (_Way_ more than the cost od a decent car, for example).
There is a cheap
trick that makes this discussion nearly on topic: Some
hackers have fited a flat bed scanner to the back of a 8"x10" view
camera. Obviously it works only for static ceens.
Sometimes you can get real 4"x5" scanbacks quite cheap, just like drum
scanners.
One word to the depth of field problem: The low end (i.e. non SLR)
digital cameras have small CCD / CMOS image sensors. Often only 1/2" in
diagonal. So the "standard focal length" on these cameras is already
quite short. As has been said already: D.O.F. depends on the focal
length. The shorter, the more D.O.F. So you get large D.O.F. out of any
"cheap" digital camera. Usually you have the problem to get a _small_
D.O.F. out of this digicams, e.g. if you wane use a small D.O.F. for
compositional / artistic purposes. (Typical: portrait of a person with
blurry background.)
--
tsch??,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/