Arca Swiss Rm3d Review
An Unusual Review of an Unusual Camera
This is going to be an unusual review of an unusual camera from an unusual company.
Arca Swiss, notwithstanding its name and antecedents, is now headquartered in France. Their first products in the technical and view camera market were introduced in the 1950's. Today they are well known for their ball heads as well as M line and F line view cameras, in sizes from 6X9cm roll film to 8X10" sheet film, as well as with mounts for digital backs .
You can read a bit about the company's history in this article, but I can't point you to the company's web site for the simple reason that it doesn't have one. Yes, as amazing as this is, here in mid-2009 Arca Swiss lacks a web site, one of the few companies of any size in the photographic industry without one. Remarkable.
The subject of this review is the Rm3d. This is a new 6X9cm technical view camera, designed for roll film backs up to that size, but optimized for current digital backs. (We'll see what that means shortly.)
A first version of the camera appeared at Photokina in 2006, began shipping in late 2007 and then was discontinued in June, 2008. The new version, the subject of this review, has a number of enhancements over the first version. All movements are geared and self-locking, it has improved ergonomics, and greater movements; vertical 30+10mm, lateral 15+15mm, and all movements are on one plane.
On The Way to This Review
When Arca Swiss contacted me to see if I would be interested in receiving a camera for review I jumped at the chance. As a long-time user of view and technical cameras (most recently the Linhof M679 and Alpa TC), I was interested in seeing this long rumoured camera because it appeared to offer a number of features and capabilities that made it unique and desirable for digital usage.
I arranged for my friend, long-time large format shooter and regular contributor to this site, Mark Dubovoy, to fly up from his home in California to my summer place in Northern Ontario and spend 4 days with me shooting with and reviewing the Rm3d. Both of us own and use several technical cameras and we both shoot with Phase One 645 camera systems, currently with P65+ backs. I requested that the Rm3d be equipped with a Mamiya mounting adaptor, and it arrived with three Schneider Apo Digitar lenses, (whose excellence both Mark and I are well experienced with), a sliding ground glass back, an optical multi-finder, and a binocular viewer. There was only one thing missing, and therein lies a tale.
But first – as they say on TV, there's a small matter of a one week delay in the camera system getting from France to Canada. A series of silly paperwork problems with Fedex and Canada Customs meant that the first three of the four days that Mark and I had available for testing were wasted on the phone with Fedex and the customs broker. The camera finally arrived at my place in the country the evening before Mark had to leave. This meant we had just a few hours together to examine and work with the Rm3d, and you'll see more of this in our video below. But first, or second...
There was also one critical piece of equipment missing, the E-Module, which was, to my mind, the cornerstone of the system. As of mid-June it was not quite ready for production, and so we had to do our test without it. At first I thought that this would not be a big issue, but as you'll see, it was and is. More on this shortly.
The Rm3d is a relatively small and light weight technical field camera weighing just under 2 lbs without lens. It can handle lenses from 24mm to 210mm. These are fitted in a proprietary Arca mount with a extremely finely pitched helical bayonet mount. Many existing Arca Swiss accessories, such as mounting plates, binocular viewfinders, compendium bellows and the like can be used.
There is a mounting slot on both the top and bottom of the camera, and a provided Arca Swiss (of course) mounting shoe which can be placed in either slot. The top one is intended for the available multifinder.
The camera has both shift and rise/fall movements as well as a built-in tilt mechanism for Scheimflug adjustments. Attractive, but not terribly ergonomic resin material grips are provided on two sides.
After a few hours of prodding and poking and only a little bit of shooting, because of our time pressures Mark and I recorded the following video based on our initial impressions of the Rm3d. Following this, and Mark's departure, I then spent a few days working with the camera on my own.
My suggestion is that you want to watch the video now because it contains a great deal of information about how the camera is designed and built. If you're unable to view the video – sorry, but time pressures prevent me from repeating the core information as text, because it would be quite lengthy. After viewing, continue with the article below, as it will then outline my subsequent impressions based on several days of field use.
As discussed in the video above, the Arca Swiss Rm3d is a beautifully designed and built camera. The quality of materials and workmanship is exemplary. The size is a bit larger than some alternatives, but since there are both rise and fall and shift movements on the front standard the additional size over an Alpa TC, for example, is quite appropriate. Of course the built-in tilt mechanism is a very welcome addition, and is something not usually found in a camera of this type.
What makes the Rm3d unique though is its extremely finely threaded focusing mechamism. The amount of precision with which the lens can be focused is amazing. That's both the good and the bad news. Here's why.
As discussed elsewhere on this site during the past few months, focusing high resolution digital backs on any camera is more critical than ever. Even AF systems are sometimes not accurate enough and many photographers have gone to high magnification eyepieces and microprism screens on their cameras.
On the Rm3d with ground glass systems (either fixed or sliding) it's even more of an issue. A very high magnification loupe is required, and even then a plain ground glass just doesn't offer the focusing acuity required to match the fine pitch of the helical, because you can't see differences of almost half a turn.
The Rm3d camera is designed to solve this issue in a new way, and this it does though the solution may not meet everyone's needs.
The are two issues to be addressed; firstly, the ability to measure the point of exact focus, and secondly the capability of achieving accurate focus once measured.
To set accurate focus the Rm3d provides what must be the most finely threaded helical mount we've ever seen, offering 1800 degrees of rotation (5 turns). Ultra precise positioning is therefore quite easily accomplished. The real trick then is in measuring the distance from the camera to the subject and then transferring this information to the focusing mount.
Finding the exact distance can be accomplished by guessing (forget it), or by measuring. While I suppose that a long tape measure would work, something a bit more technological is a better solution.
Arca Swiss offers one solution in the form of its E-module, which is an ultrasonic distance measuring and leveling device. It attaches to an electrical connection on the top of the Rm3d, as indicated in the above video.
Because the E-Module couples to the lens' bayonet mount electronically as noted in the illustration above two LEDs confirm focus. This is claimed to have 0.1% accuracy from 30cm to 12 meters.
Though an E-module was not available for testing, as while this test was conducted they are in the final process of being engineered and manufactured, some conclusions can still be drawn about how they will function.
Assuming that they work as intended, and we have no reason to imagine otherwise, the use of an ultrasonic rangefinder is highly problematic for several reasons. Firstly, they are limited in their range to about 12 meters. This may be fine in the studio, but is woefully inadequate for outdoor use. Of equal or greater concern is the issue of exactly what the device is focusing on.
With an ultrasonic rangefinder there is no way of knowing exactly what it is ranging off of. For example, two people roughly side by side, might be as much as several inches in front of or behind one another. Which one of them is the rangefinder seeing? For architectural work, is it the front of the staircase, or the fourth step. For landscape work, is it the foreground branch of the tree, or the one behind it, or the one behind that?
A much better solution in our view, and one that my colleague Mark Dubovoy uses, is a laser rangefinder. The Leica Disto A5, for example, costs about $350, and because the beam can be targeted with complete accuracy on the subject desired, it seems to us to be a much better solution. It has an accuracy of ± 1.5mm (± 0.06in) over a range of 0.05 up to 200m (0.16 up to 650ft).
So, while the concept incorporated in the Rm3d is an excellent one, and the degree of focusing accuracy is extraordinary, our preference for distance measuring would be a laser rather than an ultrasonic rangefinder.
The Bottom Line
Because I had neither E-Module nor laser rangefinder available to me during my week or testing I was limited in my ability to do a rigorous field test. Nevertheless it is possible to write, based on Mark and my tear-down session and the shooting that I could do, that this is an extremely well made and proficient camera for anyone needing a field portable technical camera with front movements, including tilt.
The precision of the focusing mount is unlike anything seen before, and Arca Swiss is to be commended for creating a fresh approach to the problem of precision focusing in the hi-res digital back arena.
Mark and I are somewhat less sanguine about the ability that one has to accurately measure the exact point of focus and then transfer that information to the camera. If the E-Module is used, and the subject is prominent enough in its field of view, then assuredly this system will work well.
It could well be though that for situations where a sonic rangefinder doesn't isolate the desired subject precisely enough, a laser rangefinder would be best.
This would then entail transferring the distance information from the rangefinder to either a printer table or the camera's optic finder's measuring scales (see video) either of which will then provide the coloured band to be set and the numeric value for precise focus. A bit tedious, to be sure, but likely to work well once one becomes adept at the process.