Body & Design

The GXR Mount A12 module slots into the GXR body, just as all previous modules do, meaning that, to a great extent, the ergonomics and handling are the same as in previous reviews of the system. In general we consider the Ricoh interface, with its jog switch/button on the right-hand shoulder and control dial on the front, to be one of the most photographer friendly systems in the mirrorless field.

The ergonomics of the GXR M-mount module are unchanged from the existing models - it's a well-built, solid feeling body that fits very comfortably in the hand.

The use of magnesium alloy with a rubber grip gives a high-quality feel and the jog switch and control dial makes it easy to operate the camera quickly without moving your hand from the shooting position.

Pressing the jog switch brings up the a selection of four user-definable settings. Jogging the switch left or right cycles through these options, and the front dial can be used to adjust the settings. The fifth, always present, option in the array is the ability to reposition the cursor around the screen, making it possible to position your magnified live view position pretty quickly. This use of the two controls, combined with exposure compensation on what would otherwise be zoom buttons on the camera's top right, makes for an easy and enjoyable shooting experience if you're the kind of shooter that enjoys changing shooting settings.

Unusually for the system, the Mount A12 module bulges out to one side of the camera. This is necessary to incorporate the focal-plane shutter design used in this module. Alongside the Mount A12 module, Ricoh has launched a leather case. The top and bottom halves of the case are available separately if you want the retro look without the inconvenience of constantly having to unhook the top cover.

The GXR Mount A12 comes with a plastic 'lens checker' that allows you to ensure your lens won't foul the camera's mount.

If your lens doesn't comfortably fit in the checker, you risk damaging both the camera and lens by attempting to use it.

Meanwhile, Ricoh is checking a wide range of lenses and will publish a compatibility list on its site.

The M-mount on the Mount module is of the original, 'dumb' design - it doesn't feature the ability to read the lens coding that Leica introduced in 2006. Instead all lens information and correction parameters need to be set and saved manually.

Lens correction options

The Mount A12 module offers the ability to correct certain lens aberrations on a per-lens basis, by selecting the most appropriate correction parameters from a menu list. Real perfectionists may therefore choose to shoot a test chart of some description, to assess the need for correction of distortion, corner coloring and vignetting. Since the camera doesn't know which aperture you've selected when you shoot, the same degree of vignetting correction will be applied at all apertures and the lens will always report its maximum aperture in EXIF (if you've programmed it in). This means correction parameters will need to be chosen carefully - for example setting the module for complete correction of vignetting with the lens wide open will result in over-correction at smaller apertures.

Several different lens corrections can be applied and then subsequently saved, as part of the camera's 'My Settings' system.
 
It's also possible to specify the name, focal length and aperture of the lens you've mounted. This data is then written in to the EXIF metadata of the images you shoot.
 
Unless you have really fond memories of adding your name to the 'Hi Score' table of arcade games, it's worth remembering to save your lens settings, so that you don't have to re-enter them too often.
 

The decision to make lens details part of the user settings might seem odd at first but it has a couple of benefits - the first is that it means you can assign lens settings (and your favoured focus assist method) to one of the three 'My mode' positions on the mode dial. The other great advantage, when working with fixed focal length lenses, at least, is that you can specify the shutter speed limit used by Auto ISO on a per-lens basis (allowing you to enforce the 1/effective focal length shutter speed 'rule,' or tailor it to your level of steadiness).

Manual focus assistance

As an all manual-focus module, it was essential that the GXR should make it easy to precisely focus whatever lens you choose to mount. It does this this using two mechanisms - magnified live view and with a 'focus assist' mode. Live view magnification offers two ways of working: a picture-in-picture magnified region or a full-screen magnified view. The degree of magnification (2, 4 or 8x) is customisable and is applied to both modes. We found the full-screen option gives a higher-resolution preview, while a quick half-press of the shutter allows re-confirmation of composition, making it a pretty usable way to work.

Magnified live view gives a choice of either picture-in-picture magnification (Enlrg Part.), or full-screen magnification (Enlrg All).
 
As you can see, the full-screen preview makes better use of the screen's resolution, to give a much clearer impression of the state of focus. A choice of 2, 4 or 8x magnification is available.
 

There are also two modes of focus assist. Much like the 'focus peaking' option recently introduced to Sony's NEX system, Mode1 highlights high-contrast edges. Mode2, meanwhile, effectively shows a 'High Pass Filter' display - showing the high-contrast regions against a grey background, for really fast working.

Helpfully, Focus Assist can be assigned to one of the camera's two 'Fn' buttons, making it easy to toggle the mode on and off whenever you wish. Perhaps more importantly, both modes remain available in magnified live view mode, giving plenty of different ways of working and making it easy to balance speed and precision of focus.

Without focus assist, even the GXR's high-res 920,000 dot screen (640x480 pixels), isn't really detailed enough for fine focusing.
 
Focus Assist Mode 1 highlights high contrast edges. These suddenly glimmer as you sweep through the focus range, making it easy to see when you've reached (or passed) perfect focus.
 
Mode 2 just provides the high contrast markings against a grey background, making it easy to use in bright light, where you might not be able to see the more subtle differences of Mode 1.
 
Either mode can be used in conjunction with both forms of magnified live view, if that's the way you prefer to work.