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#1
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Movements
I have a 4x5 Crown Graphic. It is indellibly linked with photojournalism but
hey.. If it makes people wait while you fire the shutter instead of getting in the way... Now, I want someone to clarify the technique of using front tilt to increase the zone of sharpness at a given aperture. How does one juggle focusing and tilting? Do you focus for the foreground and use the movement to increase the sharpness of the background. I presume it is a matter of a lot of playing about. The Pacemaker Graphics do not have forwards tilt on the front standard but if you drop the bed and use a bit of rise there you are. |
#2
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Not everyone will agree with this explanation but here goes
I use front tilt and swing to rotate the plane of focus to more closely line up with the plane of the subject. Back swing and tilt will do the same but these movements will also change shapes and size relationships between objects. Tilt/swings do not really enlarge the dof area as much as they align it with the pplane of the subject. As an exercise take your camera out to a road and set it up level front to rear and left to right. Focus at an approx mid point in the road as it moves away from you. The bottom of the road (at the top of the gg) and the distant section of the road (at the bottom of the gg) will not both be in focus at the same time. Now, ever so slightly and slowly begin titling the front and see what happens. This will take some practice but the amount of tilt required will be less than many people think.You may have to do a little re-focussing as you tilt. Just go slow and watch the gg and see what happens. A 4x loupe will help. Here is some suggested reading User's Guide to the View Camera by Jim Stone Using the View Camera that I wrote Large Format Nature Photography by Jack Dykinga All three are books you can get from Amazon.com steve simmons |
#3
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Not everyone will agree with this explanation but here goes
I use front tilt and swing to rotate the plane of focus to more closely line up with the plane of the subject. Back swing and tilt will do the same but these movements will also change shapes and size relationships between objects. Tilt/swings do not really enlarge the dof area as much as they align it with the pplane of the subject. As an exercise take your camera out to a road and set it up level front to rear and left to right. Focus at an approx mid point in the road as it moves away from you. The bottom of the road (at the top of the gg) and the distant section of the road (at the bottom of the gg) will not both be in focus at the same time. Now, ever so slightly and slowly begin titling the front and see what happens. This will take some practice but the amount of tilt required will be less than many people think.You may have to do a little re-focussing as you tilt. Just go slow and watch the gg and see what happens. A 4x loupe will help. Here is some suggested reading User's Guide to the View Camera by Jim Stone Using the View Camera that I wrote Large Format Nature Photography by Jack Dykinga All three are books you can get from Amazon.com steve simmons |
#4
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Neil Purling wrote:
The Pacemaker Graphics do not have forwards tilt on the front standard but if you drop the bed and use a bit of rise there you are. You'll find you need VERY little tilt to acomplish what you need for most landscape shooting. The mistake most newbies make is thinking they need to tilt it a bunch to see anything. It's not hard to modify the front standard to get a little down tilt without resorting to the bed drop ordeal. -- Stacey |
#6
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On 15 Dec 2004 00:48:34 GMT, (Largformat) wrote:
Not everyone will agree with this explanation but here goes I use front tilt and swing to rotate the plane of focus to more closely line up with the plane of the subject. Back swing and tilt will do the same but these movements will also change shapes and size relationships between objects. On my camera (Shen Hao) the back-tilt adjustment is a bit easier to handle mechanically. Easier to make fine adjustments and lock down after each iteration for focus-check. I understand there'll be some geometric distortion from back tilt, but that wouldn't show in most of my landscape pix, I don't think. As you say -- the tilt is usually slight, I'm guessing within 10 degrees of vertical in most cases. rafe b. http://www.terrapinphoto.com |
#7
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"Neil Purling" apparently said:
clarify the technique of using front tilt to increase the zone of sharpness at a given aperture. Tilts, and their horizontal counterpart, swings, do not increase the zone of sharpness. What they do, is to change the plane of sharp focus. With an untilted lens, a camera can sharply focus a plane that is parallel to the lensboard only. When the lens is tilted forward, the plane of sharp focus also tilts. Do a search for "Scheimpflug" and you'll get all the details. When your subject consists of essentially the ground between you and the horizon, with maybe a mountain in the background, tilts let you align the plane of sharp focus with the subject. The result is the appearance of immense depth of field, even with the lens wide open. How does one juggle focusing and tilting? Juggling is a good analogy. Do you focus for the foreground and use the movement to increase the sharpness of the background. I presume it is a matter of a lot of playing about. That's the usual way. Use a loupe on the groundglass to fine focus a point in the foreground, then tilt to bring a far point into focus. Go back and refocus the near, retilt for the far. After a couple of iterations things will look good. The Pacemaker Graphics do not have forwards tilt on the front standard but if you drop the bed and use a bit of rise there you are. Yup, you've figgered it out. The problem there, is that every time you tilt (with the bed dropped) you'll unfocus the whole image, so there will be more putzing around. Some people have also gotten around the Graphics lack of native front tilt by reversing the front standard. Then, of course, you lose the ability to drop the bed, unless you do some hacking on the standards. |
#8
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"Neil Purling" apparently said:
clarify the technique of using front tilt to increase the zone of sharpness at a given aperture. Tilts, and their horizontal counterpart, swings, do not increase the zone of sharpness. What they do, is to change the plane of sharp focus. With an untilted lens, a camera can sharply focus a plane that is parallel to the lensboard only. When the lens is tilted forward, the plane of sharp focus also tilts. Do a search for "Scheimpflug" and you'll get all the details. When your subject consists of essentially the ground between you and the horizon, with maybe a mountain in the background, tilts let you align the plane of sharp focus with the subject. The result is the appearance of immense depth of field, even with the lens wide open. How does one juggle focusing and tilting? Juggling is a good analogy. Do you focus for the foreground and use the movement to increase the sharpness of the background. I presume it is a matter of a lot of playing about. That's the usual way. Use a loupe on the groundglass to fine focus a point in the foreground, then tilt to bring a far point into focus. Go back and refocus the near, retilt for the far. After a couple of iterations things will look good. The Pacemaker Graphics do not have forwards tilt on the front standard but if you drop the bed and use a bit of rise there you are. Yup, you've figgered it out. The problem there, is that every time you tilt (with the bed dropped) you'll unfocus the whole image, so there will be more putzing around. Some people have also gotten around the Graphics lack of native front tilt by reversing the front standard. Then, of course, you lose the ability to drop the bed, unless you do some hacking on the standards. |
#9
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Neil Purling wrote: I have a 4x5 Crown Graphic. It is indellibly linked with photojournalism but hey.. If it makes people wait while you fire the shutter instead of getting in the way... Now, I want someone to clarify the technique of using front tilt to increase the zone of sharpness at a given aperture. How does one juggle focusing and tilting? Do you focus for the foreground and use the movement to increase the sharpness of the background. I presume it is a matter of a lot of playing about. With a camera that tilts from near the rail or bottom of the standard, I generally begin with the background (D-far), since a forward tilt inclines the plane of focus toward D-near (i.e., the axis of rotation is not centered.) This is not an exact science in my experience especially with a field camera, unless you use a camera (like Sinar) that tells you the exact degree of tilt needed based on a two point focusing of D-near and D-far. Refocusing and/or slight retilting will be necessary. In other words doing this visually usually requires some trial and error experience. And as you're altering a parallel plane of critical focus (from a zeroed camera to an inclined front standard), unless your subject is flat (receding two dimensionally) you will have objects that fall outside the adjusted inclined plane of critical focus. This is due to the Scheimpflug Rule. In other words you are actually fousing on a series of objects that vary in distance top to bottom and will also be altering the near and far limits of depth of field. Meaning since depth of field space is actually curved, your new D-far (most distant object you want in acceptably sharp focus) will be somewhere in the middle of the image area beyond the inclined plane of focus. I know that sounds a bit abstract but once you adjust the plane of focus for background and foreground, you'll need to recalulate your depth of field based on a new D-far. |
#10
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Neil Purling wrote: I have a 4x5 Crown Graphic. It is indellibly linked with photojournalism but hey.. If it makes people wait while you fire the shutter instead of getting in the way... Now, I want someone to clarify the technique of using front tilt to increase the zone of sharpness at a given aperture. How does one juggle focusing and tilting? Do you focus for the foreground and use the movement to increase the sharpness of the background. I presume it is a matter of a lot of playing about. With a camera that tilts from near the rail or bottom of the standard, I generally begin with the background (D-far), since a forward tilt inclines the plane of focus toward D-near (i.e., the axis of rotation is not centered.) This is not an exact science in my experience especially with a field camera, unless you use a camera (like Sinar) that tells you the exact degree of tilt needed based on a two point focusing of D-near and D-far. Refocusing and/or slight retilting will be necessary. In other words doing this visually usually requires some trial and error experience. And as you're altering a parallel plane of critical focus (from a zeroed camera to an inclined front standard), unless your subject is flat (receding two dimensionally) you will have objects that fall outside the adjusted inclined plane of critical focus. This is due to the Scheimpflug Rule. In other words you are actually fousing on a series of objects that vary in distance top to bottom and will also be altering the near and far limits of depth of field. Meaning since depth of field space is actually curved, your new D-far (most distant object you want in acceptably sharp focus) will be somewhere in the middle of the image area beyond the inclined plane of focus. I know that sounds a bit abstract but once you adjust the plane of focus for background and foreground, you'll need to recalulate your depth of field based on a new D-far. |
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