Circle of Confusion - applied values

"Bob G" wrote:

If extreme sharpness from here to infinity is an absolute necessity
for you I would strongly recommend a 4x5 view camera - a little tilt
and moderate stopping down will do the trick. And you'll have the
added benefit of a large negative, still miles ahead of anything from
a digital camera.

"Moderate stopping down" is a bit of an understatement.

A 4x5 camera has inherently less depth of field than a 40D. For
example, if you take a shot at f/11 with a 28mm lens on a 40D,
on a 4x5 with a 180mm lens you'd have to stop down past f/64 to
get roughly the same field of view and depth of field. If you're
lucky with your subject choice, a tilt _might_ bring that back to
f/45 or so.

CoC calcuations are based on a series of assumptions about human
factors. One of the main assumptions is that a comfortable viewing
distance varies proportionately with print size. If you're planning
a crop for a different aspect ratio, you should recompute CoC
accordingly, and using a different CoC may make sense for different
types of subjects. Overriding CoC or hyperfocal distance strictly
on the basis of print size "breaks" the theory behind the
calculation.

--
Michael Benveniste -- (Clarification required)
"The hippies wanted peace and love. We wanted Ferraris, blondes and
switchblades." Alice Cooper

A 4x5 camera has inherently less depth of field than a 40D.

You miss the 4x5 point entirely.

You can TILT the film plain and/or lens plate (relative to each other) and
produce the EXACT SAME pin sharp focus at different physical distances from
the camera. This allows for EXTREME Depth of field outside of a fixed-plain
(film or sensor) camera's capabilities.

-Frank (4x5 shooter - when I'm not playing with my toy digital...LOL!)

Frankster wrote:
A 4x5 camera has inherently less depth of field than a 40D.

You miss the 4x5 point entirely.

You can TILT the film plain and/or lens plate (relative to each other)
and produce the EXACT SAME pin sharp focus at different physical
distances from the camera. This allows for EXTREME Depth of field
outside of a fixed-plain (film or sensor) camera's capabilities.

-Frank (4x5 shooter - when I'm not playing with my toy digital...LOL!)

That is the case only when the subject is a plane surface. If you tilt
the lens to obtain focus from foreground to background (the Scheimpflug
rule) based on the flat ground in front of the camera, any tall object
like a tree will be badly out of focus at the top.

Scheimpflug really applies only to plane - or flat - objects or scenes.
The more the subject deviates from a plane surface, the less effective
tilting becomes.

And, if you are looking for competition with a 5x4 camera, a stitched
image from 9 or 16 digital shots will blow 5x4 right out of the water.

Colin D.
** Posted from http://www.teranews.com **

Frankster wrote:
A 4x5 camera has inherently less depth of field than a 40D.

You miss the 4x5 point entirely.

You can TILT the film plain and/or lens plate (relative to each other)
and produce the EXACT SAME pin sharp focus at different physical
distances from the camera. This allows for EXTREME Depth of field
outside of a fixed-plain (film or sensor) camera's capabilities.

-Frank (4x5 shooter - when I'm not playing with my toy digital...LOL!)

There are tilt/shift lenses for DSLRs...

--
Bertrand

Frankster wrote:

A 4x5 camera has inherently less depth of field than a 40D.

You miss the 4x5 point entirely.

You can TILT the film plain and/or lens plate (relative to each other) and
produce the EXACT SAME pin sharp focus at different physical distances from
the camera.

Unfortinately, the "different physical distances" turn out to
be a plane, not freely choosen distances.

This allows for EXTREME Depth of field outside of a fixed-plain
(film or sensor) camera's capabilities.

Of course, that turns out not to be the case. The DOF stays
just the same, it's just not a plane parallel to the film
plane --- and a pinhole camera has infinite DOF, so there.

-Wolfgang

"Wolfgang Weisselberg" wrote in message
...
Frankster wrote:

A 4x5 camera has inherently less depth of field than a 40D.

You miss the 4x5 point entirely.

You can TILT the film plain and/or lens plate (relative to each other)
and
produce the EXACT SAME pin sharp focus at different physical distances
from
the camera.

Unfortinately, the "different physical distances" turn out to
be a plane, not freely choosen distances.

This allows for EXTREME Depth of field outside of a fixed-plain
(film or sensor) camera's capabilities.

Of course, that turns out not to be the case. The DOF stays
just the same, it's just not a plane parallel to the film
plane --- and a pinhole camera has infinite DOF, so there.

-Wolfgang

Actually, you're right. DOF as defined traditionally, stays the same. But
since you can alter the distance from film plain you can control which
subject distances are within that (same) DOF. I will admit we are talking
about *apparent* DOF. But, it works.

As for pinhole cameras, sure... if you don't care about diffraction. Just as
stopping down to ridiculously small f-stops.

Someone mentioned that Nikon makes a tilt/shift lens. Yes... but with less
correction than a 4x5 view.

-Frank

Colin_D wrote:
Frankster wrote:
A 4x5 camera has inherently less depth of field than a 40D.

You miss the 4x5 point entirely.

You can TILT the film plain and/or lens plate (relative to each other)
and produce the EXACT SAME pin sharp focus at different physical
distances from the camera. This allows for EXTREME Depth of field
outside of a fixed-plain (film or sensor) camera's capabilities.

-Frank (4x5 shooter - when I'm not playing with my toy digital...LOL!)

That is the case only when the subject is a plane surface. If you tilt
the lens to obtain focus from foreground to background (the Scheimpflug
rule) based on the flat ground in front of the camera, any tall object
like a tree will be badly out of focus at the top.

Scheimpflug really applies only to plane - or flat - objects or scenes.
The more the subject deviates from a plane surface, the less effective
tilting becomes.

Wandering off-topic a bit...
I saw 'The Diving Bell and the Butterfly" on video last night, hoo boy
that is shot with enough lensbaby scheimpflug to make most people sick
to their stomach... they used the effect to simulate the narrator's-eye
view of a guy who went into a coma & came out completely disabled except
being able to move one eye. It's French but dubbed in English as an
option. This movie is to drama as 'Cloverfield' is to monster movies.

And, if you are looking for competition with a 5x4 camera, a stitched
image from 9 or 16 digital shots will blow 5x4 right out of the water.

Colin D.
** Posted from http://www.teranews.com **


--
Paul Furman
www.edgehill.net
www.baynatives.com

all google groups messages filtered due to spam

Colin_D wrote:
And, if you are looking for competition with a 5x4 camera, a stitched
image from 9 or 16 digital shots will blow 5x4 right out of the water.


Sort of, sometimes.

First, it simply will not work for moving subjects, and this includes
moving animals. (Clouds can be fixed in Photosop with "liquify",
however, if you are patient.

Second, 16 shots won't do to emulate a tilt. You'd need far more than
16, but if you do do far more, you can get software ot male everything
in focus.

Sure, you can emulate swings with panorama software, but you need more
and more shots to piece together as you turn to the side, and
for flat subjects you again have the no-tilt problem.

I have had great success with stitching for such things as
landscape panoramas and shots of the inside of Carlsbad Caverns,
but it is lots of work.

Doug McDonald

Scott W wrote:
[]
Moving people and objects is really not as much of a problem as you
might think, this was stitched from 6 photos, everyone and everything
was moving it it at the time.
http://www.pbase.com/konascott/image/90034426/original
[]
Scott

Captures the occasion very well.

David

"Scott W" wrote:

As for not being able to do tilts, there are not that many cases where
a tilt will really do that much good, for example in this image a tilt
would be of little use since any tilt would put part of the lighthouse
out of focus.
http://www.pbase.com/konascott/image/98893289


That would be fine with tilt. That's pretty much exactly what tilt is for
(well, with a more interesting foreground).

The DOF band with tilt is a wedge that is, of course, much wider at
distances further from the camera. So at any reasonable f stop (for example,
a 24mm lens at f/5.6 on FF, for which the hyperfocal distance is 13.4 feet),
it's really really hard for anything at a distance to be out of the DOF
band.

The place where tilt doesn't work so well is with flowers in the foreground
that stand above the ground plane.

David J. Littleboy
Tokyo, Japan