The ability to resuscitate classic manual focus lenses has been one of the unexpected side-effects of the development of mirrorless camera systems. Ricoh has responded to this trend by introducing the Mount A12 module for its GXR system. This module, featuring a Leica-style M mount, allows the fitting of a wide range of lenses onto a GXR body for the first time.
The GXR system may originally have aimed to offer optimized combinations of lens, sensor and processor, but the customer demand for the ability to mount other lenses was too much for Ricoh to ignore. There is, after all, a certain appeal to shooting a well-built metal lens on a small camera, but very few of us are willing to move back to film in order to experience it, or to spend considerable sums on a digital Leica. Ricoh clearly isn't content to sit on the sidelines as the mirrorless systems begin to respond to this pent-up demand.
The use of the Leica M-mount brings flexibility in two respects. In part because it is no longer under patent, and also thanks to its age, there are a wide range of lenses available for the M-mount. These include Zeiss, Voigtländer, Konica, Minolta and Rollei lenses, as well as native Leica designs. Just as crucially, because the M-mount has one of the shortest distances from the mount to the imaging plane, there's room to fit an adapter allowing the use of a vast range of other lens types.
The GXR Mount A12 module offers a 12MP APS-C CMOS sensor but, unlike the existing modules, it has a redesigned microlens layout designed to better cope with the wide range of lenses that could be mounted on the camera but, more importantly, it has no low-pass (anti-aliasing) filter. The company says it feels it is more important to convey the full characteristics of the lenses than to suppress moiré. The module's firmware also brings several new functions to the system, including two 'Focus Assist' modes that highlight high-contrast regions in the preview to allow fast focusing.
The ability to quickly and accurately focus manual lenses has been something of a challenge for cameras without an optical viewfinder. Plenty offer fast access to magnified live view but few offer the range of options of the GXR, which offers three levels of magnification, a choice of inset or whole-screen magnification, the two focus assist modes and a jump back to full preview when you half-press the shutter. For the manual-focus-only camera that this module creates, getting this right was essential and our initial impression are pretty positive.
Beyond this, the Mount A12 module also includes options for correcting geometric distortion, vignetting and 'color shading,' which, along with the lens name and details, can be stored as custom settings to the camera or off to a memory card. These custom settings can then be manually recalled next time you re-mount a specific lens. The lens name and details are also included in EXIF image metadata.
Also unique to this module is an electronic shutter option, for completely silent shooting at up to 1/8000th of a second. The sequential read-out from the sensor means this mode isn't ideal for fast moving subjects (it also can't be used in Bulb or Time modes), so is available only as a scene mode.
Ricoh GXR Mount A12 specification highlights
- 12MP CMOS sensor with no anti-aliasing filter
- ISO 200-3200 in 1/3EV increments
- Focus assist view for manual focusing
- 1/4000 - 180s shutter speed (1/8000th - 1s in electronic shutter mode)
- 720p30 HD movie recording
- User-defined distortion, vignetting and corner color correction, recordable for multiple lenses