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Author Topic: Tilt/Swing and Shift/Front/Back summary  (Read 2282 times)
ibear88
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« on: February 02, 2013, 06:24:11 PM »
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Do any of the Arca, Alpa or Cambo medium format cameras offer a tilt and/or swing around the center point of the lens?

Do any offer rise and shift together on the back?

I tried to sort it out on various sites. It looks to me like Arca is rise front and shift back. Alpa is rise front and shift back with the exception of an adapter that can lock down the front and move rise to the back. Cambo, I could not find an answer. For tilt and swing, it looks like both Arca and Alpa offer what may be called a base tilt (Arca builds tilt or swing into the r3dmi and Alpa offers various tilt or swing adapters. Cambo offers tilt and swing in a single lens board adapter, but I could not understand whether it is built around the center point of the lens or whether the tilt/swing sits behind the center of the lens making it similar in use to a base tilt. Arca and Alpa appear to language it that they offer tilt "and" swing. Arca really appears to offer tilt "or" swing. Alpa really appears to offer tilt "or" swing in a single adapter, but one may be able to be create tilt "and" swing by using more than one tilt "or" swing adapter at a time. What have I missed or messed up?
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tho_mas
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« Reply #1 on: February 03, 2013, 05:21:22 AM »
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Do any offer rise and shift together on the back?
Arca R-Line: yes.
Cambo WRS: yes ("RS" = "rear shift"). Cambo WDS: rise/fall on the lens, lateral movements on the back.
Alpa Max offers 4-way shift on the "back" in conjunction with said adapter.

On the Arca R-Line and on Cambo's TS lens panels T/S moves around the center of the lens. I don't know the Alpa adapter.

Arca R-Line is Tilt or Swing, Cambo is Tilt and Swing. Alpa I don't know...
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Doug Peterson
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« Reply #2 on: February 03, 2013, 08:43:42 AM »
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Thomas is correct on all his points.

The only Cambo that uses front rise is the older Cambo DS.

All the newer Cambo models (RS1000, RS1250, RS-AE) and all the Arca systems (RM3Di, RL3Di) have movements only on the rear such that the lens stays stationary. None of those systems require an adapter or tripod mount system to accomplish this; they have those feature natively.

The RC-400 and Arca Factum only have one direction of movement (rise/fall OR rotate for shift, but not both simultaneously) but do so using only rear movement.

I can't speak for alpa, as we don't carry that line.
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Doug Peterson
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« Reply #3 on: February 03, 2013, 10:28:16 AM »
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The tilt question is a little more complicated.

As Thomas points out the Cambo is {tilt+swing} while Arca is {tilt OR swing}.

However there is more to consider.

Arca allows tilt on EVERY lens (obviously the lenses with very small image circles will quickly run out of image, but it is possible to produce mechanical tilt on absolutely any mounted lens). This is because tilt is built into the arca body. Cambo and Alpa have a limited set of lenses which allow tilt/swing (notably no tilt/swing for ultra wide lenses like the Rodenstock 23HR or any Schneider wides like the 28xl or 35xl).

Cambo uses TS lens boards. This allows them to place the center of rotation closer to the fore-aft center of the  lens. Whereas Arca's tilt is from the body and therefore on long lenses it does effect a very slight rise/fall movement when tilting.

For both Cambo and Arca the tilt is centered top/bottom.
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DOUG PETERSON (dep@digitaltransitions.com), Digital Transitions
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buckshot
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« Reply #4 on: February 03, 2013, 02:14:09 PM »
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On the Arca, Alpa and Cambo 'pancake' cameras (Rm3d, STC, WRS erc.) the lens is not tilted about it's centre. Wide angle Schneiders on the Arca can get close mind you.

You can see this by looking at the picture here of the 120mm in R-line mount - when the lens is tilted, the centre of the lens is way out in front of the axis of tilt. With Cambo, the S/T mechanism is close to the centre, but it's not quite there due to the position of the focussing helical. As Doug has said, there are limits to which lenses can be tilted with both the Alpa and Cambo systems. Alpa's tilt mechanism is, to my eye, the best out there (I'm not an Alpa user) - allowing the photographer to accurately tilt insane angles like 0.1 degrees accurately - but of course, you are limited to what lenses you can use it with - e.g. the Schneider 43mm won't work, which is a shame because it is a stellar lens. If Alpa would start producing recessed boards in order to get such lenses to tilt I'd seriously consider selling a kidney and moving over.

You need to look at the Linhof Techno, Arca M-line or traditional view cameras etc. to get systems that allow you to tilt/swing pretty much any lens close to it's optical/geometric centre.

« Last Edit: February 03, 2013, 02:16:35 PM by buckshot » Logged
ibear88
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« Reply #5 on: February 04, 2013, 11:50:07 PM »
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Thank you for the clarifications.

I now understand that these tilts are more like base tilts (cambo being the closest to a nodal center tilt, but not quite so) and I'd use an iterative focus tilt focus tilt which I did with my Arca 4x5.

With wider lens I can see that many are foregoing tilts since the wider lenses allow for substantial depth of field without tilts. I did try to use an online depth of field calculator at DOF, but it does not list tech camera lenses. I used a sample coc of .2 and concluded that similar to my former Mamiya 7 that when shooting at tripod height (not table top photography or at ground level) that tilts are probably not necessary for zero to infinity depth of field. On the other hand, if I wanted to induce a narrow depth of field with a wide lense on a pancake camera that Tilts would be advantageous.

I'm curious. Where do you see the real need for tilts kick in? I'm imagining it is at about 60mm?
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Rod.Klukas
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« Reply #6 on: February 05, 2013, 10:00:39 AM »
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The Arca-Swiss tilt mechanism is axis tilt though not about the nodal point.  While not optimal, it is a useful movement to gain a bit of foreground DOF, even with wide angle lenses.  This movement may be reversed on the RM3di/RL3d & factum, to be used as swing, if desired. The rule of thumb is 1 mk on the adjustment wheel for every 30mm of focal length.  However you should test to see best maximum for your lens. My 72mm is best at 2, my 43mm is best at 1 mk of tilt. As the other movements are in the rear, (rise/fall and lateral shift) point of view/perspective remain the same.  The circle of confusion, COC, you mentioned is quite large for Digital.  You really need .007 and even .005 for most precise DOF.  .028 was the COC for 35mm film and as such many of the on line calculators are suspect.  This was partially because film was thousandths thick while digital is only a micron thick. 
We also have discovered that the lenses change character depending on the distance to the subject and the focal length.  This means that the DOF charts are not completely linear from a short distance to infinity.  This was probably always true, but wasn't discovered until the advent of precision tech cameras and the higher MP digital backs, which showed diffraction at larger apertures much sooner than film would.  This means that F-11+ is almost unuseable with backs such as IQ180 & Leaf Credo 80 and Aptus 12.  Around F8 being the best overall quality from these 80mp backs.
With film we often shot at F22 + with great results.  This covered the focus shift encountered in all lenses, and as resolution wasn't what an 80mp backs can achieve, covered most errors.
« Last Edit: February 05, 2013, 10:30:46 AM by Rod.Klukas » Logged

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Paul2660
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« Reply #7 on: February 05, 2013, 10:56:37 AM »
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Ditto to Rod's comments on tilt especially on the wides.  I use the rm3di with the 28mm Rodenstock and tilt on that lens at 1/2 a mark gives a great deal of foreground detail giving a hyper focal of about 11 ft to infinity at F11.  The 43mm Schneider definately benifits from tilt also with 1 mk giving a hyper focal of about 16 ft to infinity at f8 to f11.

One great feature of the Arca is that you can rotate it 90 degrees and get shifts of 30mm and 20mm.  However you need a lens with a big image circle to do this.  The only lens I have used that can take advantage of this great amount of shift is the 60mm Schneider.

Paul Caldwell
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Paul Caldwell
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Rod.Klukas
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« Reply #8 on: February 05, 2013, 11:54:09 AM »
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On the Arca, Alpa and Cambo 'pancake' cameras (Rm3d, STC, WRS erc.) the lens is not tilted about it's centre. Wide angle Schneiders on the Arca can get close mind you.

You can see this by looking at the picture here of the 120mm in R-line mount - when the lens is tilted, the centre of the lens is way out in front of the axis of tilt. With Cambo, the S/T mechanism is close to the centre, but it's not quite there due to the position of the focussing helical. As Doug has said, there are limits to which lenses can be tilted with both the Alpa and Cambo systems. Alpa's tilt mechanism is, to my eye, the best out there (I'm not an Alpa user) - allowing the photographer to accurately tilt insane angles like 0.1 degrees accurately - but of course, you are limited to what lenses you can use it with - e.g. the Schneider 43mm won't work, which is a shame because it is a stellar lens. If Alpa would start producing recessed boards in order to get such lenses to tilt I'd seriously consider selling a kidney and moving over.

You need to look at the Linhof Techno, Arca M-line or traditional view cameras etc. to get systems that allow you to tilt/swing pretty much any lens close to it's optical/geometric centre.



This the earliest mounting for the 120mm.  We no longer mount this way for 120mm and longer lenses.  The 120mm and longer lenses will have a rear extension tube to make the geometry of the movements more correct.
The 105mm Rodenstock does have a front only extension as does the 100mm Schneider. And as I said above, all shorter focal lengths will have only a front extension, with the Rodenstocks, due to there philosophy of design, having a longer tube and the Schneider's a shorter extension.
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Rod Klukas
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Arca-Swiss Digital Camera Solutions including R-series Technical Cameras, Large Format View Cameras, and Ballheads D4, D4m, P1, P0, Z1 & Z2.
ibear88
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« Reply #9 on: February 07, 2013, 12:45:52 AM »
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Thanks for the comments. There is a learning curve to the difference between analogue and digital, for me.

The DOFMaster website computes a depth of field of 22.8 feet to infinity when focused at the hyperfocal distance of 45.6 feet using a coc of .005 for a 28mm lens at f11.

Paul above appears to say that a 28mm lens at f11 with some tilt produces a hyperfocal range of 11 feet to infinity.

In both cases I am surprised at the apparent compression of depth of field compared to my Mamiya 7 experience and my view camera experience. Am I misunderstanding? Is the compression a product of the digital coc? Are there limits with tilts and digital backs that prevent obtaining full sheimpflug depth of field?
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David Eichler
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« Reply #10 on: February 07, 2013, 01:41:16 AM »
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Thanks for the comments. There is a learning curve to the difference between analogue and digital, for me.

The DOFMaster website computes a depth of field of 22.8 feet to infinity when focused at the hyperfocal distance of 45.6 feet using a coc of .005 for a 28mm lens at f11.

Paul above appears to say that a 28mm lens at f11 with some tilt produces a hyperfocal range of 11 feet to infinity.

In both cases I am surprised at the apparent compression of depth of field compared to my Mamiya 7 experience and my view camera experience. Am I misunderstanding? Is the compression a product of the digital coc? Are there limits with tilts and digital backs that prevent obtaining full sheimpflug depth of field?


"Digital" circles of confusion?
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ibear88
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« Reply #11 on: February 07, 2013, 11:33:04 PM »
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It could be my confusion over circles, but yes, circles of confusion as measured for digital in general was intended.
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