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#1
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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 |
#2
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Circle of Confusion - applied values
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!) |
#3
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Circle of Confusion - applied values
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 ** |
#4
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Circle of Confusion - applied values
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 |
#5
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Circle of Confusion - applied values
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 |
#6
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Circle of Confusion - applied values
"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 |
#7
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Circle of Confusion - applied values
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 |
#8
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Circle of Confusion - applied values
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 |
#9
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Circle of Confusion - applied values
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 |
#10
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Circle of Confusion - applied values
"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 |
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