Lets start with a brief history of focusing on cameras with interchangeable lenses:
- Pre Rangefinder (large format)
Plus: Very precise focusing (using loupes)
Minus: Very slow
- Rangefinder (e.g. Leica)
Plus: Small lenses, no mirror, precise focusing
Minus: Due to parallax focusing close or in the tele range does not work well
- SLR with manual focus only
Plus: no parallax as you focus though lens, Excellent tele and macro focusing
Minus: Wide-angle retro focus lenses make WA lenses big, Rangefinder lenses cannot be used, manual focus not that great (many aids like split prism screen), mirror slap induces shake and noise
- SLR with auto focus
Plus: Fast focusing if AF works for the scene
Minus: Cameras got even more bulky
- SLR with live view on LCD (Olympus showed the way)
Live View is kind of the electronic equivalent of the ground glass. You measure focus directly from the sensor.
Plus: can now focus at pixel magnification on the LCD (better use a tripod)
- Mirror-less System Camera with EVF (Panasonic G1)
Plus: Rangefinder lenses can be used, Live View through the EVF, no mirror slap, feature AF via contrast focus
Minus: EVFs are not on par with OVFs but get better and better each year. No full frame camera yet (means the RF lenses have a smaller angle of view compared to the original 35mm mount, they all feature proprietary mounts (m43, Sony E-Mount, Samsung mount)
For us the future cameras will be more and more mirror-less. The EVFs need to improve though to get close to high quality optical viewfinders.
Ricoh GXR M-Mount Module
The Ricoh GXR with M-Mount module is part of the new mirror-less trend. It is the first new generation of mirror-less camera that is dedicated to manual focus M-Mount lenses. Via adapter most lenses that exist and support full frame 35mm can be used.
We recently performed a field test with the Ricoh GXR and different modules. Overall we liked the GXR using the EVF a lot. Where to go from here? Ricoh likely realized that making many more modules with different focal length lenses would make no sense. So the decision to produce a module for interchangeable lenses seems a good concept. Now the big question "what mount?" to use.
- Ricoh own mount
- Micro Four Thirds
- Nikon
- Canon
- Leica compatible M-Mount
- Pentax K-Mount
Here are some thought about the possible decision process:
Launching a new Ricoh mount would be not a good idea unless Ricoh would be really prepared to create a larger set of lenses. There are already too many proprietary mounts out there.
Nikon or Canon mounts would not really fit to the compact size of the GXR.
Micro Four Thirds (M43) could make sense but also bind Ricoh to use Panasonic sensors. The current modules use Sony APS-C sensors (12 MP) and continue to use these sensors does not require that much change.
Ricoh just recently bought the Pentax camera division and a K-Mount could be seen in the future. For now it is far too early.
Ricoh decided for the Leica compatible M-Mount. Overall we think this is a very good decision because there are many fine and quite compact prime lenses out there that feature the M-Mount (Leica, Zeiss and Cosina/Voigtlaender). This way the user can pick his/her lens of choice and also switch lenses. Many will think that the Leica lenses are quite expensive (true). First many potential GXR users may already own M-Mount lenses and secondly other people can use alternative lenses (e.g. Voigtlaender) that are not that expensive.
The recent Fuji X100 is a great new camera but its fixed 35mm lens can also be seen as a severe limitation (for us it is). On the other side we don't really want to use the M-Mount module and switch lenses all the time. But being able to do so we can adjust the GXR to the scenes at hand.
What about manual focus only? Actually in many situations manual focus is just fine and the GXR Module has helpful aids to perform excellent manual focus. The most critical decision for the GXR M-Mount module was to use an APS-C sized sensor. We think that pragmatic decisions were the main reasons. A full frame (or close to FF) module would require the development of custom sensors and would make the product much more expensive. If photographers want extreme wide angle coverage then the GXR M-Mount module with its 1.5x multiplier maybe not that good an option. For our work it is just fine. There are 12mm, 15mm and 21mm Voigtlaender lenses available (field of view on the GXR M-Mount module like 18mm, 23mm or 32mm about). We don't know how these lenses perform and whether they can be used with the GXR M-Mount module. The M-Mount module comes with a nice plastic Lens Checker where you can check whether a lens fits or not without ruining the module.
Optimized Micro Lenses on the sensor
Ricoh added optimized micro lenses on the sensor to work better with the M-Mount Leica style lenses. In the past we had bad experience with our Leica Elmarit 28mm/f/2.8 on M43 cameras. This lens works fine on the GXR.
No AA Filter
If you think of it the AA filters are blurring the images so slightly and kind of waste the top sharpness of your fine prime lenses. Yes you can sharpen your images to counter the AA filter effect but nothing beats the natural sharpness of a sensor without any AA filter. This is also true for the GXR M-Mount module. Pictures show a very nice pixel level sharpness. Yes you may also encounter more moiré this way but way less often than you may think. Moiré was more a problem when the pixels were much bigger. Unfortunately there is a surprising downside of having no AA filter that you may not expect. Most Raw converters can sometimes produce de-bayering artifacts on extreme high frequency details.
At 300% pixel size in Lightroom 3.5RC
We checked with other Raw converters (Capture One and RAW Developer) and they showed the same artifacts at different degrees. In these more rare cases (remember this is 300%) it may make sense to try alternative Raw converters.
We have seen moiré on fabrics. In this case we took about the same scenes with a Panasonic G3 and the 14-140mm zoom. The G3 also showed about the same amount of moiré. What to do? In these cases it is best to shoot the same scene from slightly different distances.
Macro
Because Rangefinder cameras have difficulties to properly focus very close (due to parallax) there are no typical M-Mount macro lenses available. Of course the digital GXR M-Mount has no problems as it focuses directly through the lens. We used our trusty Micro Nikkor 55mm f/2.8 with a Nikon to M-Mount adapter (made by Fotodiox).
Focusing with the GXR Mount A12
There are two methods to help with manual focus on the GXR:
- Peeking (highlights edges)
- Magnification
We don't feel that peeking is for us. Other photographers report that peeking is working very well for them. We feel insecure about the perfect focus.
On the other hand the zoom magnification is a very safe (although slow) way to acquire optimal focus. For our style of photography this slower method works great. It is harder for wide-angle lenses (18-28mm) because they obviously have a higher DOF anyway. But even with an 18mm lens we felt fine.
EVF
We don't like to compose images on the LCD because of:
- Instable holding position
- Makes concentrating on a good framing hard
- LCD in bright sunlight is always a nightmare
We hardly ever would use the GXR without the optional EVF. We find the Ricoh EVF quite nice to use. The swivel mechanism makes it even more usable. Yes it also adds cost, bulk and blocks the hot shoe for other usage but it makes the GXR a much better camera. Maybe a body with built-in EVF(swivel please) is in the future for Ricoh.
We find the manual focusing with magnification so much easier with the EVF. Without the EVF we would not even have looked at the GXR.
Image Stabilization
Would be nice if the A12-M module would implement sensor image stabilization but at medium focal lengths you can compensate by shorter shutter speeds.
Tripod mount
The tripod mount is not in the center of the lens and if you use plates you have to unscrew them when you switch cards or batteries.
Handling
We find the GXR body with the M-Mount module is very easy to handle for our style of photography. Ricoh also enhances the firmware on a regular basis. We may prefer a body with integrated EVF and also a swivel LCD would be nice at times (although with the swivel EVF we hardly ever missed it).
We would like to see a RGB histogram but this is no real deal breaker either.
Quite often we get frustrated with cameras that produce good images but their handling is slow. With slow I mean long waits till I can analyze the proper exposure or if the camera takes ages to write the images to the card. The GXR M-Module never gets there at any point. The live histogram gives us a good hint about the proper exposure and the preview is ready for analysis shortly after we took the shot.
Technical Image Quality
Not having an AA filter allows sharper images from the 12MP sensor. The 12MP Sony sensor is not one of the latest generations. This may show with very high ISO and some pixel peeping. We are personally quite pleased with the results we got. Also 12 or 16 MP is not that much of a resolution difference anyway.
Lenses we used
We used as couple of M-Mount and Nikkor lenses. Why did we not use our old Nikkor lenses before? Using MF lenses on today's DSLRs is no fun. It got better with live view but the mirror-less cameras with EVF allow focusing even without a tripod.
Leica Elmarit-M 28mm f/2.8 (equivalent angle of view of full frame 42mm)
This is a very sharp lens. This was the lens used when we encountered the de-bayering artifacts.
Leica Summicron-M 50mm f/2 (equivalent angle of view of full frame 75mm)
Also a very sharp lens We like this angle of view a lot.
Zeiss Distagon T* 18mm f/4 ZM (equivalent angle of view of full frame 27mm)
This lens performed fine but showed some minor vignetting in the corners (at f/5.6). 18mm was actually the widest lens we tried. For full frame 18mm is an ultra wide-angle lens while the 1.5x multiplier unfortunately downgraded to a standard 27mm lens.

Zeiss Biogon T* 21mm f/2.8 ZM (equivalent angle of view of full frame 31.5mm)
This would be nice lens to archive a standard wide-angle for the GXR M-Module. We liked how it worked.
Voigtlaender Color-Heliar 75mm f/2.5 (equivalent angle of view of full frame 112.5mm)
This lens shows how good the not so expensive Voigtlaender (today a Cosina brand) can be. We like the results a lot. If you shoot freehand you need to keep the shutter speed fast though (we try to stay at about 1/200 sec).

Micro Nikkor 55mm f/2.8 (equivalent angle of view of full frame 82.5mm)
This lens maybe not as razor sharp as the Leica lenses (not sure any other lens is) but still liked the rendering a lot. Having a macro option for the GXR M-Mount is very important. We don't really use it for real macros but more for close-ups.
Note: a lens we own from about 1975
Micro Nikkor 55mm with Fotodiox adapter
 
Nikkor 20mm f/3.5 (equivalent angle of view of full frame 30mm)
We bought this lens in the 70th and it is a nice performer. The angle of view is equivalent to a 30mm full frame lens.
 
Sample Image Gallery
Conclusion
The GXR M-Mount module did all we hoped for. It is an ideal camera to use with manual focus lenses of your choice. Manual focus gives the photographer a lot of control and focusing can be very precise. The M-Mount module made us more excited to use some of our manual focus lenses again. We liked to use this camera a lot.
What are the alternatives if you like to use fine prime lenses?
- M43 cameras: Their 2x multiplier makes shooting wide-angle with M-Mount lenses even harder. Also the sensors are not built for these lenses and can show corner softness at wider angles (e.g. our 28mm Leica Elmarit). On the other side these cameras are more versatile as they also allow the use of auto focus lenses.
- Sony E-Mount cameras (e.g. the new NEX-5n and NEX-7): To be seen.
- Leica M9: This is way more expensive and not really considered to be an alternative.
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