Thursday, February 3, 2011

Ricoh GXR A12 50 mm F2.5 Macro Preview

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Review based on a production Ricoh GXR body with firmware v1.05 and A12 50mm lens unit with firmware v1.05

This is the first of two reviews of the GXR; as each module is effectively a completely different camera we've decided to treat them as such and produce separate reviews. This review covers the GXR with the A12 50mm equiv f2.5 (12MP APS-C sensor) module, the next will cover the GXR/S10 24-70mm equiv (10Mp 1/1.7" sensor) combo. The first half of both reviews is the same, covering the GXR camera body and system.

In the short, frenetic history of the digital camera it has often been the smaller, less high profile manufacturers who have taken all the risks and experimented with more unconventional designs and solutions. For despite all the technological advances in the last decade the majority of digital cameras have designs that follow the same basic blueprint as their analog predecessors: they're essentially the same cameras with a sensor in the place of film.

This is especially true in the interchangeable lens camera sector, where the big players (coincidentally those who led the market in the days of film), hampered by the need (desire) to retain compatibility with their legacy analog systems, produce digital SLRs that would feel reassuringly familiar to any photographer from the late '80s or early '90s who by choice or circumstance had missed out on the digital revolution.

Last year saw the first serious challenges to the dominance of the single lens reflex (a design that can trace it roots back over 100 years, and that hasn't changed fundamentally since the 1950s) in the interchangeable lens camera market - thanks to the introduction of Micro Four Thirds by Olympus and Panasonic. Since then Samsung has also introduced a very similar system ('NX') which is based on a larger APS-C sensor.

So when we first heard from Ricoh that they wanted to come and show us a new system camera we presumed it too was going to be variation on the 'mirrorless' design. Then we started to get hints that it was actually a totally new idea (or, as mentioned at the bottom of this page, a very old idea resurrected).

Where Micro Four Thirds and similar systems aim to cut bulk by removing the mirror box, which slims down the camera body and somewhat reduces the size of the lenses (though by how much depends on the sensor size used), they still end up pretty big once you add zoom lenses (and if we're talking about long zooms or telephotos the advantage is all but lost - large sensors require large lenses). Thus the idea that these 'hybrid' cameras can offer SLR quality and versatility combined with compact camera size is simply not possible.

Ricoh's answer to this problem is, to say the least, novel. Rather than selling a camera body with a fixed sensor, the GXR system uses interchangeable lens/sensor units - every lens comes in a sealed unit complete with sensor, shutter, aperture, processing engine (there's also one in the camera body) and the motors necessary to focus the lens (and drive the zoom mechanism if present). You are, essentially, buying a new 'camera' every time you buy the lens: the GXR body is little more than a shell containing the screen, card slot, controls and flash. This radical rethink of the 'interchangeable lens' has some important consequences:

Different lens units can have different sensor sizes and technologies (CCD or CMOS, for example)By using a smaller (compact camera) sensor the GXR system can offer very small zoomsLens units can be designed for specialist applications (video optimized lens and sensor for example)The overall performance of the system is essentially defined by the lens unit, not the bodyEach lens has its own leaf shutter - which will generally be quieter, and offer faster flash sync than the focal-plane shutters used by Micro Four Thirds

The GXR body (which is like a slightly over-sized GR or GX model) can thus be anything from a high speed compact super zoom (a la Panasonic TZ series) to an APS-C compact with a fast prime lens (think Sigma DP2 or Leica X1) simply by swapping lens units. By replacing the lens unit with a compact projector, printer or high capacity storage device it could stop being a camera completely, at least that's the theory.

Unique flat sliding lens mountInterchangeable sealed lens/sensor unitsCompact Magnesium Alloy die-cast body with 'GR coating'Extensive customization options and external controls3.0" 920,000 pixel LCDBuilt-in flash and accessory shoeOptional electronic viewfinderHDMI connector

The standard components of an interchangeable lens camera are split between the GXR body and the lens unit in such a way that the performance of the camera (focus speed, image quality and so on) is to a large degree defined by the latter, with the body taking care of operational aspects and the actual process of taking the picture. Both camera and lens unit have their own Ricoh Smooth Image Engine processor (complete with RAM), though it appears the one in the lens unit is only used for capture and to get raw data off the sensor and convert it from analog to digital before it is sent to the body for processing and file creation. A fast, wide data bus connects the two halves together. To get a rough idea how the components and tasks are split see the table below (or check out the block diagram on the next page).

 JPEG processing and file creation Live view processing and display AV and PC interfaces (external I/O) Raw file processing (incl noise reduction if used) Image stabilization (gyro and sensor shifting) LCD screen and EVF (if attached)

Each lens unit contains instructions and parameters specific to its own sensor and optics, meaning that different lens units will change slightly the features, behavior and performance of the camera body when attached. Some of the lens unit dependant attributes (that we currently know of or can deduce) include:

Image processing parametersNoise reductionMenu options - lens units define what menus you seeDistortion correction (and, presumably, other lens corrections)Shutter speed and aperture rangesProgram mode parameters ('program lines')Specific features (manual focus ring, sensor-shift stabilization etc)Focus speedContinuous shooting speedBuffer (no of frames and speed)Movie capture capabilities (resolution and frame rate)

Essentially, as mentioned elsewhere, with each lens unit you're getting a completely new camera with very different capabilities. Whether this is a good thing or not is going to depend on how well Ricoh does with its stated aim of using highly optimized lens/sensor combinations, and how much it is prepared to invest in producing a range of options that's compelling enough to tempt buyers away from more conventional systems such as Micro Four Thirds.

In the first part of this review (pages 1-12) we will have a close look at the GXR's body, features and user interface. In the second part (studio and real-life tests) we focus on the GXR with the A12 50mm module. The tests with the S10 module will be published in a separate review.

If you're new to digital photography you may wish to read some of our Digital Photography Glossary before diving into this article (it may help you understand some of the terms used).

Conclusion / recommendation / ratings are based on the opinion of the author, we recommend that you read the entire review before making any decision. Images which can be viewed at a larger size have a small magnifying glass icon in the bottom right corner of them, click to display a larger image in a new window.

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Dpreview use calibrated monitors at the PC normal gamma 2.2, this means that on our monitors we can make out the difference between all of the grayscale blocks below. We recommend to make the most of this review you should be able to see the difference (at least) between X,Y and Z and ideally also A, B and C.

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