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primus96



Joined: 13 Nov 2003
Posts: 209
Location: Yorkshire, United Kingdom

PostPosted: Sun Aug 22, 2004 8:26 pm    Post subject: Reply with quote

When using my Graphic I wanted to increase the area of sharp focus.
Am I right that I need a tilt forward of the front standard to get this effect?
Although the front standard won't tilt forwards I can drop the bed.
Should I also raise the front with the rise to re-centre the lens or not?
Should I then change the point where I focus?
These may sound dumb to a view camera user but I wanted to know.
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t.r.sanford



Joined: 10 Nov 2003
Posts: 812
Location: East Coast (Long Island)

PostPosted: Sun Aug 22, 2004 10:26 pm    Post subject: Reply with quote

The general rule for focusing on a plane that's not perpendicular to the back of the camera is to extend an imaginary line connecting the top and bottom of the focal plane until it forms an angle with the subject plane, then tilt the front so that a line drawn perpendicular to the optical axis passes through that angle.

In other words, the plane of the back and the plane of the lensboard both intersect the plane of the subject at the same point.

Of course, all this assumes that the lens produces an image circle sufficiently large to include the film when it's tilted.

When you drop the bed of your camera, you tilt the lens down. You can use the existing tilt control to lessen that tilt. You usually start with the front raised so the lens comes back to where it would be if you had a conventional tilt available. You can lower it if this helps the composition.

This "Scheimpflug" maneuver works well when nothing interesting in the subject plane sticks up too far! Good for patterned carpets, mosaic floors, fields of equal-height flowers, and so forth.
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Nick



Joined: 16 Oct 2002
Posts: 494

PostPosted: Sun Aug 22, 2004 10:39 pm    Post subject: Reply with quote

If you want more DOF use a smaller F/stop. By tilting you're changing the plane not the amount of DOF.

[ This Message was edited by: Nick on 2004-08-22 15:40 ]
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glennfromwy



Joined: 29 Nov 2001
Posts: 903
Location: S.W. Wyoming

PostPosted: Mon Aug 23, 2004 3:41 am    Post subject: Reply with quote

By tilting the lens forward a bit, you will get more of the picture in focus without stopping down so much. In fact, with enough patience and fiddling around it is possible with some subject matter to get the entire scene in sharp focus without stopping down at all. The method is generally used to get the foreground in sharp focus while stopping down enough to focus to infinity. It's a fiddly process, and heres how to do it with an Anny or Pacemaker: drop the bed after you bring the lens out to the infinity stops (assuming a "normal" lens). Raise the front to where you want it (another story) and tilt the standard back. Focus on the subject. The focus movement will be limited by the track hinges and you may have to re-adjust the position of the standard. Tilt the front down a tiny bit, and here the fun starts, pick an aperture you can see with and follow this rule --- focus far and tilt near, in small increments. Very small. Keep doing this until the entire scene, from near to far is in sharp focus. Requires a dark cloth, a loupe and a lot of patience but the result can be well worth the effort.

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Glenn

"Wyoming - Where everybody is somebody else's weirdo"
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primus96



Joined: 13 Nov 2003
Posts: 209
Location: Yorkshire, United Kingdom

PostPosted: Sat Sep 04, 2004 5:43 pm    Post subject: Reply with quote

Can you clarify the focussing method?
I focus farther away than without movements?
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glennfromwy



Joined: 29 Nov 2001
Posts: 903
Location: S.W. Wyoming

PostPosted: Sun Sep 05, 2004 2:55 am    Post subject: Reply with quote

The most important thing to remember is that the area of sharp focus (depth of field) runs roughly 2/3 behind a subject and 1/3 in front. A lot of folks waste the far depth by focusing on the subject and stopping down too far, thus the far focus depth may run way out past infinity.
The near focus depth suffers as a result and things in front of the subject will be fuzzy. Get yourself a hyperfocal distance chart for your lens, for starters. Then you can focus on the hyperfocal point for your subject, then tilt, re-focus, repeat until everything is sharp, from infinity right up to the nearest blade of grass. It sounds more complicated than it is. Of course, this does not apply to scenes that require an out of focus background. It's more for landscapes and such. A good book on view camera technique will help you understand.
Good luck ------------------

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Glenn

"Wyoming - Where everybody is somebody else's weirdo"
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primus96



Joined: 13 Nov 2003
Posts: 209
Location: Yorkshire, United Kingdom

PostPosted: Sun Sep 05, 2004 10:50 am    Post subject: Reply with quote

The lenses I have are a 150mm f4.5 Xenar and a 150mm f9 G-Claron.
Do Schneider publish information on hyperfocal distances for their lenses?
However, it seems that I should be focussing on a closer point in the scene because the foreground details are more distracting if unsharp.
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Nick



Joined: 16 Oct 2002
Posts: 494

PostPosted: Sun Sep 05, 2004 1:35 pm    Post subject: Reply with quote

Scheinder publishes DOF charts for various formats and focal lengths. They use different COC I guess for each format. Which brings up the point. If you can find a DOF program on the net then you can input whatever circle of confusion [COC] you want and create your own DOF charts.

But you can just go to the Scheiner website and print out thier charts. They should be listed under info.
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FixerFiend



Joined: 05 Sep 2003
Posts: 42
Location: Washington D.C.

PostPosted: Sat Sep 11, 2004 12:47 pm    Post subject: Reply with quote

Also, If you google "Depth of Field" you will come across several real good programs you can dload for free that let you simply type in any info(Focal lenght/f-stop/near far distances) and it will magically give the hyper focal distance for those circumstances. I've found 2 seperate applications. One is called "fcalc". Now these dont take movements into account.

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45PSS



Joined: 28 Sep 2001
Posts: 3232
Location: Mid Peninsula, Ca.

PostPosted: Sun Sep 12, 2004 5:39 am    Post subject: Reply with quote

and about 2 years ago a dozen or so links were posted on this fourm and a search should turn them up.

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While a picture may be worth a thousand words, a quality photograph is worth a million.

[ This Message was edited by: 45PSS on 2004-09-11 22:40 ]
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