IMO the advantage of the Sinar is the sliding adapter with integrated loupe. I would think if one wants to tilt often and to precisly focus this would be more compfortable than switching between groundglass and digiback manually.
The R-Line has a built-in
Micro-Precision helical focus mount, onto which a rich
selection of high-performance lenses can be attached through
an exclusive bayonet mount. Subject distance and depth-offield
can be measured electronically and displayed on an LCD.
Leveling is done either electronically or through precise spirit
levels. The unique viewer, Vario-Finder, is for lenses with a
focal length from 23 to 210mm. The Rm3d and the RL3d have
individual self-locking AIP shift movements for the X and Y
axes, which are in the same film plane. Additionally, the cameras
offer a tilt mechanism for optimizing sharpness.
I am making inquiries about what exactly is meant by 'measured electronically and displayed on an LCD'. I am also interested to find out exactly what the difference is between the various RM types..
The arTec is a nice piece of equipment and now has a gear driven tilt function (lack of which was a flaw in the original design)
In either case I am unconvinced about using a fresnel with 3X magnifying loop to achieve anything much - the viewing area is too small. Another concern I have with the Sinar is the actual sliding device - more complexity = more that can go wrong.
Finally - I am not a big fan of the Sinar's point of attachment to a tripod. I dont need their built in rotating base...which makes the mounting of panorama rails and nodal point rails - less than elegant and in fact down right ungainly.
At any rate it isnt rocket science focusing wides on technical cameras - if you get a chance have a look at the distance scales on Schneider or a Rodenstock - you will see what I mean. Also I find DOF tables amazingly insightful...eg what do you think the DOF of 'acceptable focus' is with a 35mm Schneider at F11?
I am hoping that Arca's eccentric lack of web site and readily available information - may be one of those contra indicator situations - where the company's deficiency in one area is more than made up by the excellence of the product.
