Looking for feedback on the Arca Swiss 4x5 F-Metric

[neil poulsen]

Here are two reviews of the 45TK from B&H . . .

http://www.bhphotovideo.com/c/produc...5s_Camera.html

By accounts, it's an very nice camera.

[Theodoros]

As the Arca F line resembles the accuracy of L cameras due to its swing mechanism approach (which aims to ensure entrance pupil accuracy for lenses that the entrance pupil coincides with the mounting flange and for image areas that are on the rear standard's plane), I don't think there is much in-between the Arca or the TK for one to choose from... it's purely a matter of preference IMO... Yet, I would also add the Horseman L 45 in my choices as it is cheeper, sturdier and easier to convert for different image areas down the smallest digital ones... All of these cameras do have their swing mechanism underneath the side-shift one though and thus combination of these two movements on the same standard has to be avoided.

EDIT: I just realised that the F-classic isn't like the F-Universalis on the positioning of its shift mechanism (which I thought was the case - sorry about that) but it has its shift mechanism above all other mechanisms, rather than bellow all other as it (correctly) is positioned on the Universallis or the Monolith... I have then to recommend the TK as a much better option than the F-Classic (or a Horseman L45 - even better IMO) as combining any shift with any tilt or swing on the same standard with the F-Classic, it will cause distortion on the image... It is strange that the people in Arca have corrected things on the Monolith or the F-Universalis, but left the F-classic with the handicaps that have been avoided on the other cameras of the Arca line.... Sorry from my part too for not noticing in the first place.

[Rory_5244]

Hi 12pmc, yes, sea water and cameras don't mix. I used the Schneider 47mm XL lens with a recessed lens board on the Arca just fine.

[12pmc]

Thank all for your comments.

Emmanuel. - do you know if it's possible to visit the Arca Swiss factory, or even if they have their own website, because I cannot find it?

Thanks
Peter

[Theodoros]

There is no Arca Swiss site... only Arca shop. Arca sells much of its stuff directly to the customers at the same price as retailers do.

[Emmanuel BIGLER]

...Emmanuel. - do you know if it's possible to visit ...

It is of course possible to meet the Arca Swiss people, see and manipulate all products under the supervision of those who design and make Arca Swiss products!

Simply place a phone call and make an appointment.
People speak English, German and French fluently.

ARCA SWISS INTERNATIONAL
29, rue de Châtillon
Quartier de l'Europe
25480 École Valentin
France
phone: (+33) (0) 3 81 85 40 60
This is located very close to Besançon, close to the motorway A36, exit #4. From Nice to Besançon, travel time by car is about 7h30.
And you can also reach Arca Swiss International by train + 10 minutes walk, no car required, same travel time about 7h30. Train station is named École Valentin (or Ecole Valentin if you use a train planner web site)

[12pmc]

Theodoros, thanks for that, and

Emmanuel, appreciate the coordinates, will make a visit.

Merci
Peter

[Theodoros]

Theodoros, thanks for that, and

Emmanuel, appreciate the coordinates, will make a visit.

Merci
Peter

Peter, if you pay a visit to Arca, please ask them to explain to you on why they've designed the F-line shift mechanisms above than the shift/swing ones... Putting a shift mechanism above a tilt one, means that if a combination of the movements is performed on the same standard, the rotation centre (where the entrance pupil of the lens should be - ideally) "drops" or "shifts" with the swing mechanism operation... focus is altered and there is distortion (ellipsis instead of circle) on the image captured. The same is with side shifts and swings... if they are combined on the same standard, the entrance pupil of the lens operates like being on a door (!!! - never on an axis - it moves on the perimeter of a circle) ...Now, they did things right on the Monolith, (all shift mechanisms below the tilt/swing ones) so ask them why they did things different on the F-classic!

That said, there will be no problem if one operates an F- classic and avoids to use combination of swings & side shifts, or of tilts and vertical shifts on the same standard (no problem with the Monolith), but since the extra mechanisms are not right on the F-classic, why not consider the F-Univesalis that is lighter, cheaper and does (correctly) all the F-clasic does, avoids the mistakes of the F-classic and even has a shift mechanism on the front standard that is (correctly) positioned below the tilt & swing mechanisms?

Another thing to bear in mind... On the Arcas, (all Arca - the Monolith too) yaw free operation is only ensured if the lens entrance pupil is positioned on the lens board (the Orbix system), if one uses a retrofocus lens that has its entrance pupil in a different plane than its mounting (like a Mamiya RZ lens, or a Hassy V and many others), you then can "kiss yaw free operation good bye".... But again, yaw free operation isn't assured with the "arc type" mechanisms either... But the arc-type systems are far easier to correct for this (if one cares to convert his lens boards so that each different lens he uses is mounted with the entrance pupil exactly positioned at the centre of which the arc-type mechanism is part of the perimeter - or better, if one converts the mounting frame to be sliding back & forth on the standard). Hope this helps....

[12pmc]

Theodora's. I will indeed ask them, but may need some if the answer gets too technical!

[Theodoros]

Theodora's. I will indeed ask them, but may need some if the answer gets too technical!

They are honest people in Arca Peter... They'll admit that it's wrong to combine swings with side shifts, or tilts with Shifts on the same standard. Think about it....

Say you are using a symmetric lens on an Arca F-line, or another lens designed so that its entrance pupil is positioned exactly where it mounts... Then if you tilt the frame, you'll notice that the entrance pupil remains at a constant point by which all tilting is happening... It is the centre of a circle that has a radius as long as the distance from the tilting mechanism... Now if you shift the lens, won't the amount of shifting added to the radius? ...but the tilt mechanism's radius is constant, isn't it? As a result the lens entrance pupil is no longer the center of the circle, but it rotates around the centre at a radius that equals the shifting amount.

Now this error (that causes distortion of the image recorded but change of focus too) wouldn't be happening if the shifting mechanism was underneath the tilt one would it? You would then shift the lens with the tilting mechanism and thus the lens entrance pupil would remain at the centre of the circle of which the tilt mechanism is an arc all the time! (like it does with the Monolith or the F-Universallis) Same thing is what is happening if the side shift mechanism is above the swing one... In this case it is even easier for one to understand since swing is happening around an axis that passes through the entrance pupil of the (symmetric) lens... If side shift is above the swing and one side shifts, the lens centre will be moved right or left from that axis and thus swinging the lens at the same time will cause the lens to rotate around the axis...

I've used a camera like that in the past and I can tell you, the difference in having a distortionless image is far more than one may think and is quite visible. Off course one may avoid the problem by using only tilts and swings on the front standard and only shifts on the rear standard, but there are many-many cases, where you have to use shifts on both standards (especially if the capture involves stitching). Thus, I changed my other camera for a Sinar P2 (which -like the Monolith has all shifting done underneath tilts) and now I even convert the P2 as to have the lens entrance pupil position and the image area position adjustable, so that I will secure fully distortionless operation despite the lens or the image area (mirrorless, MFDB, DSLR , film) used...