Ricoh GXR A12 Field Report
Leica M Lens Mount and an Interchangeable Sensor
Be Careful What You Wish For
OK, You asked for it – a digital camera with interchangeable sensor. Why buy a whole new camera every time a new generation of sensor comes along – you asked, and many are still asking. The answer is – because few companies have the moxie to make such a device. Ricoh does, and has.
But, until now Ricoh didn't quite get it right. The reason is that the sensor lies between the body and the lens, and not having a line of interchangeable lenses (at the time), Ricoh decided to sell their sensor models with lenses built in. Humm. Not so attractive; A – because it means that one is stuck with just one lens, and B – when you upgrade the sensor you lose the lens as well.
With the just shipping (September, 2011) Mount A12 (catchy name isn't it?) Ricoh has taken their GXR interchangeable sensor concept and made it click (pun intended). Instead of a sensor with a lens, to attach to your GXR body, they have produced a sensor with a lens mount; a Leica M lens mount to be precise.
Ricoh GXR with A12 M Module. Leica 50mm Summilux @ ISO 200
A $1,000 Digital Leica?
No – of course not. Firstly, it's not from Leica, it's from Ricoh. Secondly it has none of the cache or build quality of an M Leica. But, with that clear and behind us, the Ricoh GXR with A12 M Module (GXR-M from now on) represents a remarkable value for anyone looking for a home for their Leica M mount lenses who doesn't have the $7K needed to buy an M9.
Before we look at what the GXR-M is, let's be clear what it is not. It is most definitely not a rangefinder camera. There is a live view LCD and an optional electronic viewfinder. An accessory shoe also allows for generic optical viewfinders to be used. But there is no traditional built-in optical viewfinder / rangefinder the way that there is on an M series Leica.
Given that the art and practice of rangefinder use is becoming something of a historical craft (similar to manually shifting gears on a car with a floor clutch) most younger photographers may find themselves feeling more at home with an LCD and an EVF.
Why bother then? The answer is, to paraphrase American political pundit James Carville, "It's the lenses stupid!".
Compared to DSLR lenses, M mount lenses are small. Without a mirror and prism mechanism rangefinder style lenses can have a much shorter back focus distance, and when it comes to wide angles, the bulkiness of an SLR retrofocus design isn't needed. Their small size also allows M lenses to be fast. Leica, for example, has 21mm, 24mm, 35mm, and 50mm f/1.4 aperture lenses in its line-up.
Ricoh GXR with A12 M Module. Leica 24mm Summilux @ ISO 200
Few would disagree that Leica is among the world's finest lens makers. For nearly a century they have been at the zenith of lens design and manufacture. Leica's M series lenses are some of the few optics in the world still being built with the highest possible optical and mechanical precision. And, as one might expect, they are priced accordingly. Most new Leica M series lenses cost between US $2,000 and $6,000, and a few even higher. But, unlike the plastic wonders that cost just a few hundred, a Leica M lens is for many photographers a life-time purchase.
Current demand for Leica M lenses far exceeds the company's manufacturing capacity. For this reason you will find that most dealers are out of stock on almost every lens, and have waiting lists. There is a thriving used Leica lens market, though you may find used lenses that are in high demand commanding prices close to or even exceeding list price.
That's why it is so exciting to have a new camera to put them on. The M9 is the only current M camera from Leica. It's a classic rangefinder and costs some $7,000. If you don't care for optical window viewing and rangefinder focusing, or the price gives you a nose bleed, your choice till now have been limited. Of course any Micro Four Thirds or Sony NEX E mount camera can take Leica M lenses with an adaptor. My June, 2011 article Leica M9 Second Body Alternatives discusses this, but as we'll see there are potential problems.
As interesting as these are, the Ricoh GXR-M has a unique proposition, only matched by the M9 itself. It does not have an anti-aliasing filter. Many would argue (me among them) that the blurring filter that almost all DSLRs and CSCs have takes the edge off the extremely high resolution and contrast that Leica M lenses have, and therefore dilutes the Leica "look" that is well appreciated by that marque's aficionados. By the way, I would say that Carl Zeiss M Mount lenses fall into the same category, and some of the better Cosina / Voitlander M-mount lenses are very highly regarded as well.
Of course there are many hundreds of older Leica screw mount lenses (only a small adaptor is needed) that will also mount on the GXR-M, many of them quite excellent and relatively inexpensive via Ebay, pawn shops, and private sales.
If you're not already familiar with Reid Reviews (a subscription site) you may want to check out his exhaustive lens reviews – some of the best and most comprehensive available, and done by a real photographer not a technician.
Autumn Cows – Clearview, Ontario. October, 2011
Ricoh GXR with A12 M Module. Leica 135mm APO Telyt-M ASPH @ ISO 200
Design and Features
I know that this going to sound contradictory, but the GXR is at the same time one of the simplest camera designs around, and yet the most full featured. But, before delving into the controls and how they aid or hinder ones photography, a few words about the GXR's modular concept.
As can be seen in the product shot at the top of this page, the entire front of the camera is removable. In the case of the M module it contains the sensor and a Leica M lens mount. There are also four other modules available, each containing a sensor and fixed lens combination. You can read more about these here.
The M module's sensor is a CMOS design with 12.3 Megapixels. The size is APS-C. It has microlenses specifically designed for the back-focus distance of Leica M lenses, and as already mentioned, does not have an anti-aliasing filter. This latter point may be one of the most important contributors to the GXR-M's very high image quality.
With the exception of the Leica M8/M9 and Sigma's Foveon sensor cameras, only medium format cameras have been sold without AA filters. The GXR-M now joins this exclusive club. When you then use a very high quality lens, and good technique (exact focus, high shutter speed, or tripod), appropriate aperture (not too wide open, not to stopped down), images from the GXR-M just sing. There is a clarity and a microcontrast that shows up not just in on-screen images, but in prints as well.
The 12.3 Megapixels files from the GXR-M are not the highest resolution on the block, but this is of sufficient size that excellent 16X24" prints can be made, which is as big as most people typically print. Certainly in the chemical darkroom days it was very rare to make prints larger than this, and even now it's only my exhibition landscapes that I regularly print larger.
Of course large files lend themselves to greater crop-ability, if needed. But, if one works carefully, 12MP is enough for most of what I do, and certainly for the type of street shooting that such a camera lends itself to best. I'll trade high quality pixels for lots of mediocre ones any time.
Ricoh gets Brownie points for using DNG as their raw format. One can only wish that the major camera makers would take a page from Ricoh's book and stop the madness of endlessly proliferating proprietary raw formats. Come on guys. Get with the program. Once again kudos to Ricoh for being forward thinking and customer focused in their choice of a non-proprietary raw format.
For focusing non-AF lenses almost all Live-View cameras have an image magnification capability, as does the GXR-M. But this doesn't give the critical focus accuracy that a rangefinder like the one on the M9 can produce. In 2010 Sony added focus peaking to the NEX-5 via a firmware update, and now the NEX-5n and NEX-7 have it as well. The Ricoh GXR-M has it in two forms, one similar to that which Sony features, where a shimmer effect shows up around the edges of the subject with highest contrast, and therefore sharpest focus. The other, illustrated above, turns the entire screen into a B&W etched outline. Ricoh calls these Mode 1 and Mode 2 respectively.
I really like Mode 2. I have set up the GXR-M so that Fn1 activates and deactivates peaking, while Fn2 activates and deactivates center focus magnification. Half pressing the shutter release always instantly returns the LCD or EVF to regular viewing. I find that this combination works very well for me.
Just one parenthetical note. Because Leica M lenses have manual aperture rings one will always achieve best focus by doing so with the lens wide open. If you try and focus with the lens stopped down to shooting aperture, particularly at smaller apertures, depth of field can lead to some inaccuracy. My method of working is to open the lens wide (counter-clockwise), focus, and then stop down to shooting aperture. Once you know how many "clicks" it is to a given aperture one can do this with the camera at eye level.
Of course if shooting rapidly changing subjects then I revert to traditional hyperfocal zone focusing, making the whole focusing excercise moot.
I admire the level of customizability offered by the GXR-M. Its designers really do appear to be photographers themselves.
For example, there is a button market Direct, which offers a screen with virtually all of the camera's major settings available together at once. But, one can also program the thumb-accessible ADJ lever to call up five different control parameters from a list containing just about every setting that the camera can do. Similarly there are two Function buttons on the rear control wheel that can take on almost any function, and even the zoom rocker on the rear panel (which zooms the lenses on modules so equipped) can be programed to change exposure compensation or other similar variable features.
There are three MY positions on the mode dial. One can set all of the camera's operational controls and then save them to one of these positions, providing instant access as shooting situations vary, or even as one changes sensor / lens modules. These can be user-named on screen, so there is no mystery as to what they are, and can even be saved to memory card and reloaded on the same or a different camera.
Laying Fallow – Clearview, Ontario. October, 2011
Ricoh GXR with A12 M Module. Leica 35mm Summilux @ ISO 200
Fit and Finish
One of the things that I've always admired about Ricoh camera products is that they are almost always well made and beautifully finished. No – not up to Leica M standards, but then not with Leica M prices.
What also appeals is that Ricoh "gets" photographic usability, unlike some camera makers whose engineers are clearly very talented but who sometimes seem as if they never actually use the products that they design.
For example, the top panel mode dial on the GXR locks with a small button. Intentionally changing the shooting mode simply means pressing the latch with ones forefinger while using ones thumb to rotate the dial. But, it will never accidentally be changed as the camera comes in and out of ones bag or pocket.
One of the few complaints that I have with the camera is that the rear LCD is fixed. Articulated LCDs are now the norm, and coming from a camera that has one to the GXR-M which doesn't, does feel a bit restricting. The EVF does tilt though.
Battery life in my few weeks of usage was about 250 frames before the Low Battery indicator appeared. I imagine that I could have gotten another 50–75 frames before it pooped out. This is decent, but not great battery life.
I learned from a friend that the GXR-M battery is exactly the same as the battery used in the Fuji X100. These batteries are also widely available from third parties at modest prices, as are small chargers with built-in wall plugs, something that the Ricoh doesn't offer. Of course like all manufacturers Ricoh cautions against third party batteries, but my guess is that most of these all come from the same factory in China in any event.
Ricoh shares a problem common to many of the second and third tier camera makers – distribution. In Canada, for example, the brand is completely unavailable at retail. In the U.S. there are a handful of dealers, but it's mainly online retailers such as Adorama and B&H that service the brand. Maybe via its Pentax acquisition Ricoh will find a broader distribution network.
Inconsistancies, Bugs, and Annoyances
No camera is without fault, and the GXR-M certainly has its share. Here, in no particular order, are the ones that I've found, and which bug me the most.
– The camera can not shoot just raw. A JPG is always recorded along with the DNG file. What's that about? I don't want a JPG. I don't need a JPG. This may be the only camera I've ever seen that forces a JPG on the raw shooter. It's a waste of card space and waste of time having to delete them after download.
– There is no raw buffer when shooting single frame raw. Why not, since there is a buffer when shooting multi-frame?!
– There is no histogram visible on the instant review image. There is a live histogram when shooting, and one can be displayed afterwards. Just not on instant review. Why not?
– The GXR-M will wake up from "sleep" mode by touching the shutter release, if the LCD screen is active. If the optional EVF is active it will not wake up from sleep mode. One has to turn the camera off and then on again to bring it back to life.
– My camera overexposes by 1 stop. I have to work with -1EV dialed in all the time. Sean Reid reports that his exposes as well as most other digital cameras that he has tested. Guess mine's miscalibrated.
– The default is for the menu system to always revert to the top item of the top menu. Before this drives you mad, set "Store Menu Cursor Position" on Screen Three of the Setup menu so that your sanity is preserved.
– When Auto-ISO is used the ISO which the camera sets is to the nearest single digit. In other words, ISO 1181, for example. I sure wish that this level of precision was matched by an equal level of exposure accuracy, but I somehow doubt it.
– The tripod socket is not directly underneath the lens, rather, well to the right. This could be very problematic for anyone who does nodal point panos or other critical work.
All of these flaws were discovered the first afternoon that I spent shooting with the camera. Doesn't anyone at Ricoh test this stuff before firmware is finalized prior to shipping?
Autumn Begins– Clearview, Ontario. October, 2011
Ricoh GXR with A12 M Module. Leica 24mm Summilux @ ISO 200
Vs. NEX or MFT
The final question before declaring the Ricoh GXR-M the winner of the "least expensive M lens compatible camera sweepstakes" is, how does it compare to either an MFT or NEX camera option, as discussed in my Leica M9 Second Body Alternatives article from earlier this year.
After using the GXR-M for several weeks I see two things as being vital to a Live View M lens alternative. The first is focus confirmation via "peaking", and the second is the availability of an eye level viewfinder. As this is being written (early October, 2011) the Sony NEX-5n with the FDAEV1S electronic viewfinder is now shipping, while the Sony NEX-7 is about 6 weeks away. These are the only two other cameras, besides the Ricoh GXR-M, that offer peaking focus confirmation with M lenses and an electronic viewfinder. (I hope that Panasonic and Olympus also add focus peaking to their next models in support of third party manual focus lenses. Image magnification alone just isn't sufficient).
The GXR-M (body and A12 module) along with the optional VF-2 viewfinder, will cost about $1,220. The Sony NEX 5n with OLED electronic viewfinder and a high quality M lens adapter will cost about $1,040. The Sony NEX-7 with similar lens adaptor will cost about $1,290. Thus, the NEX 5n is the least expensive, the GXR-M is in the middle, and by a small margin the NEX-7 the most expensive of the three.
Note that the new 2.3MP EVF used in the NEX-7, and available as an accessory on the 5n, is vastly superior to the one for the GXR-M.
So – which is the best from a handling perspective, and which from an image quality perspective? When it comes to user interface the GXR-M is the hands-down winner. Sony has really improved the interface on the NEX 5n and 7 over the original NEX 3 and NEX 5 models. The 5n also now enjoys a touch screen, and the 7 has their innovative TRI-NAVI interface, and its EVF is of course built-in.
Both Sonys also have eye-detect for their EVFs. This is a plus for the Sonys that is not to be underestimated. While shooting at eye level is the advantage of any type of viewfinder, having to manually switch between it and the rear LCD for image review and settings is annoying, and slows one down when trying to work quickly. The Ricoh disappoints on this count.
Distillery Truck – Toronto, Ontario. October, 2011
Ricoh GXR with A12 M Module. Leica 24mm Summilux @ ISO 400
The Ricoh has a 12 MP sensor, the Sony NEX 5n's is 16 MP, and the NEX-7 is 24MP. The extent to which this difference in resolution is important to any user will be a function of that person's particular needs. Certainly for large prints and extensive cropping the more megapixels the better.
I have not had a chance to yet compare the GXR-M and the NEX 7. But I have been comparing the Ricoh against the NEX 5n, and frankly nearly going blind and mad in the process. There are so many variables, pitfalls and challenges in doing this that all I intended on doing here is to provide my anecdotal impressions.
The lack of an AA filter on the Ricoh is an advantage, but not an overwhelming one. It would appear that the AA filter on the 5n is in fact quite weak. The higher resolution of the 5n does compensate though, and while one might argue that there is a bit more microcontrast from the GXR-M, this really is a pixel peeping quibble. I discuss the GXR-M's microlens advantage due to being specifically designed for the M lens' back focus later in this report. It does give an advantage to the Ricoh though.
The GXR-M's peaking works well, but regrettably in comparison to that on the NEX-5n, which I happen to be field testing at around the same time, is not as good. Mode 1 is difficult to see in low light, and Mode 2, while it works better, creates an etched cartoonish look to the image, which is distracting. The 5n's peaking can have three different colours and levels of intensity, and I found it to be much more effective than that on the Ricoh.
The GXR-M's sensor is that of a previous generation, while the 5n and 7 use Sony's latest sensor designs. The Ricoh is a decent performer, but I see cleaner images at all sensitivity settings from the 5n, even the lowest. At ISOs above 1600 the 5n has a very clear advantage. The NEX-7 will not be a high ISO champ, but I'm guess that it will be the equal of the GXR while having double the megapixel count.
Then there's the issue of "extras". The Ricoh's video mode is fairly basic, with 1280X720 at 24p using Motion JPG. The new Sony's are full HD at up to 60P using AVCHD 2 and a much higher data rate.
Finally, it musn't be ignored that while GXR-M can take all M and compatible lenses (and only these), the Sonys take not only M compatible lenses but also Sony's E series autofocus lenses, Sony's full line of A series lenses with Phase Detection autofocus via their new LA-EA2 adaptor, and a wide range of other brand lenses as well via third party adaptors.
Of course the Ricoh counters these Sony advantages by offering a variety of sensor / lens modules, from APS-C sized to small ones with autofocus and zooms.
Factory Graffiti – Toronto. October, 2011
Ricoh GXR with A12 M Module. Leica 35mm Summilux @ ISO 200
Vs. the M9
There's little point in comparing the Ricoh GXR-M and the Leica M9. These are such different animals operationally, and are priced so far apart (the M9 is some $6,000 more expensive), that while one could have fun pixel peeping the differences (they're there, but not as great as one would think) the real differences lie in their appropriateness for a given shooting style, not in their image quality per se.
Regular readers know that I have been shooting professionally and personally with Leica M cameras since the mid-1960's. I've owned M2, M3, M4 (I skipped the M5) M6, M7, M8 and now M9 bodies. I currently own seven Leica M lenses; 24mm, 35mm, and 50mm Summiluxes, the 90mm Summicron and the 135mm APO Telyt. I also have the last generation 28-35-50mm Tri-Elmar, and the 16-18-21mm Wide Tri-Elmar. In other words, I'm a Leica aficionado as well as 45+ year user.
I know it will be heresy for some to hear this, but the reality is that rangefinder focusing has, for me at least, passed its best-before date. Yes, I can do it with my eyes closed (metaphorically speaking), but that doesn't mean that it's the best way to focus. Formula One cars now have automatic transmissions rather than floor shifter and foot clutches. They simple work better.
So what's better than rangefinder focusing (and let's leave autofocus out of the equation, because traditional M lenses don't have AF)? The answer has existed for years on video cameras – focus peaking. Combine this with also available image magnification (both of which the GXR-M has), and one can focus most manual lenses as accurately and as quickly, if not more so, than with a coincident rangefinder.
Few would disagree that the classic Leica M series rangefinder camera works best with lenses in the 35mm – 50mm range. Maybe as wide as 28mm, and maybe as long as 90mm. Wider than 28mm and one needs to use an accessory viewfinder, and at 90mm and longer the image area in the VF is just too small for accurate composition.
What this means is that wider lenses (16mm through 24mm) and longer ones (90mm and 135mm) actually become a pleasure to use on a live view camera with focus peaking and a decent EVF. Working with the GXR-M (and the new Sony NEX-5n which also has peaking and an EVF) brings a new life to these wider and longer lenses. Just keep in mind that these are APS-C format cameras and therefore really wide lenses are not in the picture (so to speak).
Fall Brambles– Clearview, Ontario. October, 2011
Ricoh GXR with A12 M Module. Leica 35mm Summilux @ ISO 200
I should also mention the question of focusing a rangefinder camera on subjects, such as the one immediately above, where there are no edges and lots of dense repeating detail. I don't exaggerate when I say that it can be almost impossible, which is a shame, because a camera like an M9 with a pocket full of primes is a wonderful hiking set-up. Focus peaking on the GXR-M though makes this a breeze.
One final thought, before you go flying off in all directions and start writing irate missives against Reichmann on various Leica boards. Please note that I am not referring to optical viewfinder composition when I call into question the continuing attractiveness of the M8/M9 viewing system – just the RF focusing aspect. One is always free to use an OVF on the accessory shoe, and zone focusing and hyperfocal focusing are also always an option, regardless of what alternative focusing methods one may choose to use.
The Focusing Quandary
Things are never as simple as they appear. I've made the point that I find viewing with very wide angle and with long lenses superior using a Live View camera than with a camera such as the M9, either with accessory viewfinders or the camera's. And certainly focusing longer lenses by using peaking turns out to be highly accurate and fast.
But, manually focusing lenses wider than about 28mm starts to become problematic when using peaking because depth of field is so deep that the shimmer effect is hard to isolate precisely (at least on the GXR-M), even when a lens is focused wide open. On the other hand the Leica M9's rangefinder is extremely accurate and quick to focus with WA lenses.
There are numerous aspects to image quality, including resolution, dynamic range, and noise characteristics. Measuring resolution I leave to the sites that do it well, and similarly with DR, which is the most difficult to quantify. Enough to report here that when used with top-ranked lenses the sensor on the GXR-M, due to its lack of an AA filter, produces images of exceptional resolving power.
Noise is easier to measure. Anyone can do it at home with careful technique and a bit of patience.
Below are 100% crops of the image above. A Leica 90mm f/2 APO Summicron was used, with the aperture fixed at f/2.8 while varying the ISO between 200 and 3200. The camera varied the shutter speed automatically in Aperture priority mode. These images are from raw files processed in the Lightroom 3.5, with no sharpening or noise reduction.
|ISO 200||ISO 400|
|ISO 800||ISO 1600|
|ISO 3200||ISO 3200 with Noise Reduction & Sharpening|
ISOs 200 through 800 are essentially noise free. I write essentially, because even ISO 200 does show some texture in deep shadow areas at 100% on screen. But, in the real world, on prints up to 16X24", there is no noise to speak of in this range.
At ISO 1600 some light luminance noise is visible and it becomes obvious at ISO 3200. As with most contemporary cameras there is virtually no chroma noise at any ISO speed.
But, as shown in the last comparison frame, even ISO 3200 can produce decent results with just a bit of luminance noise reduction and a touch of sharpening in Lightroom 3.5.
Symmetrical Vs. Retrofocus Lenses
Before Leica produced the Leica M8 they announced that creating a full frame digital M Leica would be impossible, because the rear register distance (lens mount to sensor plane) was too short, and that there would be vignetting, colour casts, and other issues. But, this was before micro-lens technology had matured. Today, cameras such as the Sony NEX and Micro Four Thirds have register distances even shorter than that of the Leica M.
But there still is a potential issue, and that relates to lens design. All wide angle lenses from Leica since about 1980 have been of retrofocus designs. This means that the rear element of the lens does not protrude too deeply into the camera, which can prevent peripheral light rays at the edges and corners of the image from entering the photo sites properly. This can lead to vignetting, reduction of resolution, and colour casts.
So, while medium to long Leica M lenses do not present a problem with the GXR-M, there is potential for lenses that are of symmetrical design, such as the Carl Zeiss wide angle ZM Biogon lenses and WA's from Voigtlander, to have an issue. Some wide Leica M lenses as well.
I did some testing of two lenses of symetrical design – the Voigtlander Heliar 15mm f/4.5 and the 21mm Skopar f/4, kindly loaned to me by Nick Devlin. My point of reference was the Leica Tri-Elmar 16-18-21mm f/4. I did not see any real problems with either the 15mm Heliar or 21mm Skopar at any aperture when used on the GXR-M. This is good news, because if the GXR-M is to be regarded as a "poor man's Leica" then it better work with moderately priced alternative lenses.
Voitglander 15mm f/4.5 Heliar /// Leica Wide Tri-Elmar @16mm
In the example above, shot at f/5.6, we see that there is a bit more vignetting with the Heliar, but I'm almost certain that this is a characteristic of the lens, since I've seen it on M9 images taken with this lens. Resolution to the corners is excellent, better in fact than the WATE. But we also see a slight magenta cast in the upper left corner of the Heliar frame. This means that with this lens, at least, the microlens design of the GXR-M is not totally able to handle a symmetrical lens design.
An alternative interpretation is the the lens is decentered and the GRX-M may not be at fault at all. Not having another Heliar to test I'm unable to confirm this. But I have also noted colour casts in one corner or another, or two, with other similar cameras and other lenses, so the exact cause of what is being seen remains unclear.
I hasten to point out though that this is the worst instance of lens cast (if that's what it is) that I've seen from the GXR-M. Using both the Heliar and the Skopar for many dozens of test and example shots I have not seen very much lens cast at all, and certainly none with the more retrofocus design lenses which make up the bulk of my collection. Note that it is also very easy to correct lens cast such as this with Capture One software. It has a built-in lens cast correction capability. All one needs to do is take a series of frames of a white card at each aperture and then turn them into lens cast profiles. From then on just apply the appropriate aperture profile to each shot. The only hitch is that the camera's EXIF fields do not contain info on the shooting aperture, and so one needs to make reliable written notes for this to work.
There is a Color Lens Cast menu selection on the GXR-M which looks like it will do the job nicely. I could find no instructions on how to use it, and didn't take the time to figure it out because I saw so little lens cast problems with any lens used, except the 15mm Heliar, and even then it was slight.
Further Thoughts on Lens Compatibility
I decided to do some research on the whole issue of lens compatibility with non-Leica digital cameras when using Leica brand and third party M lenses. I spoke extensively with Sean Reid of Reid Reviews, an acknowledged expert in this area. He in turn contacted some of the top people in lens design to get their impressions and experience.
The summary is that Leica lenses since at least 1980 are virtually all retro-focus designs and so tend to pose less of a challenge for digital cameras than do wide-angle symmetrical lenses. Certainly my 24mm and 35mm Summiluxes and also Wide Tri-Elmar have no trouble at all.
The notable exceptions are the Leica 28mm f/2.8, Leica 18mm f/3.8, Leica 24mm f/3.8 and Leica 21mm f/4. These compact lenses can all pose more of a challenge for a digital sensor than other modern Leica lenses. Other lenses which are potentially of concern are the compact Cosina Voigtlander wide-angle lenses starting with the 28/3.5 and the Zeiss ZM Biogons.
I haven't tested them on the Ricoh yet but the camera's microlenses, designed especially for rangefinder camera lenses, may be a particular advantage (compared to NEX or mFT cameras) with these smaller Leica wides.
As this review is being published I am doing field work with the new Sony NEX-5n and will be testing it with the 15mm Heliar and 21mm Skopar as well as with my Leica glass. A report on how this camera fares with M mount lenses will be part of that review later in October.
The Bottom Line
The Ricoh GXR-M is a very appealing camera for anyone who owns Leica M mount lenses, or who would like to. At 1/7th the price of an M9, and with its very good build quality and wide ranging features, it's a relative bargain. A Live View LCD and an optional EVF give the GXR-M capabilities that many users, even those that may currently own an M9, will find very attractive. Certainly it can serve as an ideal back-up body for an M9 owner.
Ricoh is to be encouraged for having the moxie to build an interchangeable sensor modular camera. The Mount A12 will hopefully be only the first with a special lens mount, with a Pentax AF mount and higher resolution APS-C sensor to follow. The new relationship between Ricoh and Pentax is bound to lead to some fascinating products, and hopefully the company will continue to innovate along these lines.
If you are interested in reading more about the Ricoh GXR-M, you may want to read Sean Reid's recent article here on this site, and for even more in-depth coverage his full review on Reid Reviews (a subscription site).