Panasonic G1 Hands-On Preview

Panasonic G1 Introduction

Hands-On Preview: 09/12/08
UPDATE 10/2/08: We've gotten our hands on a G1 prototype that's final hardware/late firmware, and put it through its paces timing-wise. It's pretty zippy, check out the Performance tab of this review for all the details.
UPDATE 10/23/08: Test shots from a production-level G1 posted! Click on the Samples tab for all the test images we've taken so far, including links to select RAW files.
UPDATE 11/04/08: Full Test Results posted from a production unit! Click on the Optics, Exposure and Performance tabs and subtabs for all the details, and stay tuned for the full review.

At the start of August, 2008, Panasonic and Olympus Corp. -- its partner in the Four Thirds coalition -- jointly announced the development of a new standard for interchangeable lens cameras, dubbed "Micro Four Thirds." At the time, we described the news as perhaps the most significant camera-related announcement of the year. Just over a month later, the Panasonic G1 has been unveiled as the first Micro Four Thirds product. That Panasonic was first to bat for Micro Four Thirds, rather than its imaging industry partner Olympus, is newsworthy in itself. It shows just how seriously the consumer electronics giant is taking digital imaging, and indeed how much acceptance Panasonic now has in a market once dominated by the traditional camera companies. Just a little under five years since it first became a Four Thirds partner -- and only two years after it shipped its first digital SLR -- Panasonic is now in the position to really push development forward in a big way.

We'll discuss the Micro Four Thirds standard in a bit more depth below, but let's first take a look at the camera, which is certainly looking like an impressive debut for the new standard. The Panasonic Lumix DMC-G1 definitely fulfills the size promise of Micro Four Thirds, coming in at 0.25 - 0.3 inches (6 - 8mm) smaller in every direction than the current joint title-holders for world's smallest digital SLR, Olympus's identically sized Four Thirds-system siblings the E-410 and E-420. Body-only weight is just a scant 0.2 oz (5g) more than that of the E-410, which is the current record-holder for the crown of lightest digital SLR. So it's not quite the lightest we've seen for an interchangeable-lens digital camera, but definitely very close.

In this svelte frame, the Panasonic G1 has placed a 12.1-megapixel Live MOS image sensor with 4-channel readout, and a newly developed Venus Engine HD imaging processor. Together, these are capable of providing a 60 frames-per-second Live View function, as well as three frames-per-second shooting for up to 7 Raw or unlimited JPEG frames (to the available card / battery capacity, obviously). Panasonic has included a Supersonic Wave Filter dust reduction system in the Lumix G1, as seen in past Four Thirds cameras, which helps to clear dust from the image sensor and avoid the possible adverse effect on image quality.

As well as accepting Micro Four Thirds lenses, the Panasonic G1 can also use existing Four Thirds lenses courtesy of a special converter. Obviously this won't be a totally optimal solution, since Four Thirds lenses will be larger and heavier (and there's the slight added size and weight of the converter to take into account as well), but it will likely prove a useful stopgap measure for photographers shooting with both systems, especially until a wider selection of Micro Four Thirds lenses are available. (Note though, that not all current Four Thirds lenses are able to support contrast-detect autofocus: Some current Four Thirds lenses will only support manual focus on the G1.)

Two Micro Four Thirds lenses have been announced alongside the Panasonic G1: a LUMIX G VARIO 14-45mm/F3.5-5.6 ASPH/MEGA O.I.S. lens, and a complementary LUMIX G VARIO 45-200mm/F4.0-5.6/MEGA O.I.S. lens. The names should immediately suggest it, but it bears mentioning anyway: both of these first Micro Four Thirds lenses include mechanical image stabilization, important given that there's no provision for stabilization in the camera body itself. The 14-45mm lens will be included in the camera bundle, and the 45-200mm lens will be available for purchase separately.

On its rear panel, the Panasonic G1 sports both a large 3.0-inch LCD panel with a resolution of 460,000 dots that's mounted on a tilt-swivel mechanism allowing viewing from a wide range of angles, as well as an electronic viewfinder (or EVF). Knowing that this would have to compete with the true optical viewfinders on digital SLRs, Panasonic has wisely selected a rather impressive EVF display. Using a responsive Liquid Crystal on Silicon design that is alternately front-lit by a trio of red, green and blue LEDs some 180 times per second, this display has an impressive 800 x 600 pixel resolution with full color at every pixel location, and no gaps between pixels. (Most electronic viewfinders have adjacent red, green, and blue dots for each pixel, and gaps between pixels, resulting in a perceived loss of quality and "graininess" that makes them off-putting). The LCOS display takes advantage of the human eye's persistence of vision, to provide a high-res full color image at the same 60 frames-per-second rate that the live view is being streamed off the Panasonic G1's image sensor.

Focusing is achieved by contrast detection using data streamed from the image sensor, with either single or continuous modes available. There's a choice of 23-area or single-area autofocusing, with the latter allowing the AF spot to be positioned anywhere in the frame. There's also a face detection AF mode, and AF tracking is possible. While contrast detection AF systems are generally quite a bit slower than the phase detection AF found on most digital SLRs, Panasonic is claiming focusing speeds in the order of 0.3 to 0.4 seconds from infinity to two meters, using the kit lens.

The Panasonic G1 offers the regular Program, Aperture-priority, Shutter-priority, and Manual modes you'd expect to see on an interchangeable lens digicam, and also includes an improved version of the Intelligent Auto mode that we've seen on some of the company's past compact camera models. There's also a nifty Aperture and Shutter Speed Preview function, which simulates the effect of changes to either variable, allowing novice photographers to see what the effects of their adjustments will be. ISO sensitivity ranges from 100 to 3,200 equivalent plus Auto ISO, and there's also an Intelligent ISO function which determines if your subject is in motion, and then raises the sensitivity as necessary to freeze the action. Shutter speeds range from 60 - 1/4,000 second, plus a bulb setting which is limited to a maximum of approximately four minutes, and x-sync is 1/160 second or less. Metering is achieved with a 144-zone multi-pattern system, and offers a choice of intelligent multiple, center weighted, or spot metering modes. The Panasonic G1 offers both a built-in, seven-mode popup flash with a guide number of 11 meters at ISO 100, as well as an intelligent hot shoe to cater for external flash strobes such as Panasonic's FL220, FL360, or FL500.

The Panasonic G1 stores images on Secure Digital cards (including the newer SDHC types), and is also compatible with MultiMedia cards. The Panasonic G1 draws its power from a proprietary 7.2V, 1250mAh lithium-ion rechargeable battery pack that's rated for about 350 shots per charge when using the electronic viewfinder, or 330 shots when using the LCD display, both figures complying with CIPA testing standards, when using the kit lens. Connectivity options include both USB 2.0 High Speed for computer connection, and both standard and high-definition video. For standard-def television, there's NTSC / PAL switchable composite video output, while high-def is achieved via a MiniHDMI Type C (version 1.3b) connection.

Panasonic will be selling the Lumix G1 digital camera in the USA from mid-November 2008. The Panasonic G1 will be sold as a kit which will include the camera body in either black, red, or blue colors, plus the previously described 14-45mm Micro Four Thirds-mount lens, battery with charger, and a software bundle including PHOTOfunSTUDIO viewer 2.1 E and SILKYPIX Developer Studio 3.0 SE. A second Micro Four Thirds lens, the aforementioned 45-200mm model, will be available separately during November 2008. Pricing for all of these products has not yet been disclosed, but is expected to be announced in early October.

What Exactly is Micro Four Thirds?

Given that the Panasonic G1 is the first Micro Four Thirds camera to be announced, it might be good to take a quick look at just what Micro Four Thirds is all about.

Panasonic and Olympus' Micro Four Thirds standard is aimed at allowing a significant reduction in the size and weight of interchangeable lens digital cameras, achieved by eliminating the bulky mirror box from the design. With the mirror box gone, the "back-focus distance" (or back focal length) of compatible lenses can be reduced. Technically, back focus distance is defined as the distance from the vertex of the lens's rear element to the sensor, but for practical purposes, it's easier to speak in terms of the distance from the lens-mounting flange to the sensor surface. In the existing Four Thirds system, this dimension was 40mm; for Micro Four Thirds, it has been slashed to just 20mm. Obviously, this change allows for a significant reduction in the size and weight of the camera body while retaining the same sensor size.

That's not the only benefit, though. As well as smaller and lighter camera bodies, Micro Four Thirds also offers the possibility of a significant reduction in the size and weight of the lenses, too. While the physical size of a lens depends somewhat on the size of the image circle it must produce, it turns out to depend even more strongly on the back focus distance the lens was designed for. Reducing the back focus distance can dramatically decrease the length of the lenses needed to cover the area of a Four Thirds image sensor. Lenses for the new system can also be somewhat smaller in terms of diameter as well, and indeed the new mount is some 6mm smaller (44mm vs 50mm) than that called for in the original Four Thirds standard.

Removing the mirror box does have some possible disadvantages, though. Obviously, it removes the possibility for any Micro Four Thirds camera to offer a true through-the-lens optical viewfinder, with no way to divert the optical path to the viewfinder between exposures. Hence, Micro Four Thirds cameras will be limited solely to using a Live View function as seen on certain recent digital SLRs, where data streaming from the image sensor can be displayed on an LCD display, electronic viewfinder, or both. For similar reasons, with nowhere to put a phase detection autofocus sensor, Micro Four Thirds cameras are limited to using contrast detection autofocus. While this can offer higher focusing accuracy, and negates problems with front or back focusing, contrast detection has in the past always been slower than the phase detection systems found in digital SLRs. Panasonic claims to have addressed this in the Lumix G1, and our first impression is that they've achieved their goal.

Bottom line, the Micro Four Thirds system promises interchangeable-lens cameras with good performance at significantly smaller overall sizes. With the Panasonic G1, early indications are that the platform is off to a solid start.

Panasonic DMC-G1 Hands-On Preview

by Dave Etchells

I first saw a very early prototype of the Panasonic G1 back in June of 2008, when I and a handful of other key editors from around the world were briefed on the Micro Four Thirds concept in Osaka, Japan by Panasonic engineers and product planners. At the time, I was quite taken by the G1's physical appearance and compact size, but had reservations about the concept of a high-end digital camera that would be restricted to contrast-detect focusing (the main reason digicams have such poor shutter response relative to SLRs). Now that I've been able to hold and shoot with a fully functional sample, I'm happy to say that many of my concerns have been addressed. Our final judgement on the Panasonic G1 will of course depend on how a production sample performs in our laboratory and shooting tests, but indications so far are very encouraging. Even with the rather preliminary firmware that exists at this time, the camera seems to perform quite well, and image quality frankly appears higher than I had anticipated. Read on for more about my experience with this first G1 sample:

While its compact size is one of its primary selling points, the first thing that really caught my eye about the Panasonic G1 was its overall elegance, more so than its spare dimensions. The camera has a two-part wrapping, with the bulk of the exterior covered in a slightly soft-feeling material that can be either black, dark blue, or dark red. I'm not normally a fan of color on cameras (and would probably still opt for the all-black version myself), but have to admit that the blue and red versions look awfully classy. It's hard to define, but something about the Panasonic G1's design just makes you want to pick it up and hold it in your hand. I think it might have something to do with the way light reflects softly from the matte finish of the camera's covering, but whatever the reason, Panasonic's designers deserve high praise for the work they did on this camera body.

Then too, while I'm not a big fan of colorful cameras, I don't really fit the profile of the Panasonic G1's target market. This is a camera that's been designed specifically to appeal to people moving up from point & shoot cameras, but who've been put off by the size and complexity of typical SLRs. I expect the colored bodies will be very popular with a lot of soccer moms and other women who'd prefer a camera that's a bit less aggressively masculine looking than the stereotypical big, black SLR.

Though it is slightly heavier than the E-420, the Panasonic G1 is smaller than any current SLR body. The images above show the G1 posed next to an Olympus E-420, one of the smallest SLRs currently on the market. The difference in size isn't dramatic, but it's enough that the Panasonic G1 does feel smaller and more compact when you hold it in your hand. This shot also illustrates how much smaller the Micro Four Thirds lenses are than equivalent ones for the normal Four Thirds system: The two lenses above have nearly identical specs (14-42mm f/3.5-5.6 on the left, 14-45mm f/3.5-5.6 on the right), but you can see that the Micro Four Thirds lens is noticeably smaller, despite its inclusion of lens-based image stabilization.

So, while the Panasonic G1 is definitely smaller than the smallest SLR on the market, it's not (yet) pocket-sized. On that topic, a senior Panasonic product planner who briefed us on the camera said that they actually could make even smaller bodies using the Micro Four Thirds standard, but they were concerned that US users in particular would find them too small. I suspect that's the case in general, but I'd bet that a really small "rangefinder-style" Micro Four Thirds camera would find a lot of takers among people looking for a very small camera for street photography and other traditional rangefinder uses.

Despite the Panasonic G1's small size, though, its large grip makes it well-suited to a range of hand sizes. The shot above shows a woman's hands holding the camera, so it's easy to see that the grip isn't so big as to be awkward for people with small hands to hold. Surprisingly, though, I found it quite comfortable to work with, despite my long-fingered appendages. Another well-executed design element.

The shot above also shows the tilt/swivel LCD screen extended. This is a beautiful screen; it's big (3 inches) and bright, and quite sharp, with 460,000 dots of resolution. There's also an auto-brightness option that will brighten the screen by as much as 40% when you're in bright light. Any LCD is hard to read in sunlight, but the G1's brightness boost does help some.

Panasonic G1 Full-time Live View

By its nature, the Panasonic G1 is always in "Live View" mode: In that respect, it's like any point & shoot digicam with the combination of an electronic viewfinder and rear-panel LCD that works as a viewfinder as well. The differences with this camera are that it has interchangeable lenses, focuses a lot faster than the average digicam, and has a larger sensor to provide better low-light performance than typical pocket cameras.

To their credit though, Panasonic seems to have made more of an effort in the G1 to have the viewfinder display accurately mimic what you'll see in the final image file once you've snapped the shutter. They seem to be trying to go the point & shoot market one better with their viewfinder display accuracy and simulations, and based on my brief time with a prototype, seem to be succeeding.

The shots above show two options the camera gives you for viewing your subject in record mode. On the left, the subject fills a larger area of the display, but the exposure information is overlaid on the bottom of the image. This gives more image area, but potentially makes the exposure info a bit harder to read. If you'd like, you can instead opt for a smaller view of the subject, putting a sharply contrasting black background behind the exposure readouts, making them easier to see. The row of camera-mode information across the top of the display is always overlaid, Panasonic perhaps figuring that this data is less critical on a shot-by-shot basis, and so not worth spending the screen real estate to put a black background behind it.

There are a couple of grid options available, as well as a histogram display with a nifty trick: You can position it pretty much anywhere on the display screen that you like. Here, I've put it in the lower right corner.

Now here's a feature that really made me take notice when I saw it: An LCD preview mode that simulates the effect of long shutter times! The shot above is a simulation that I lifted (with permission) from a Panasonic presentation, because the simulation apparently isn't output on the NTSC video output: I couldn't capture it with the little frame grabber I had along when I was checking out the G1 prototype sample. (We'll try to capture an actual example with a video camera aimed at the screen, once we get a production model to test.) This will be great for novices learning about the effects of shutter speed on their shots, as it makes those effects "what you see is what you get" in the viewfinder. In the prototype demo, we pointed the camera at little race cars running around a track, and the increase in motion blur as we reduced the shutter speed was quite obvious. Pretty slick!

We'll have more about the Panasonic G1's user interface in another day or two, but for now we've prepared a page showing its operating modes and menu layouts. See our Panasonic G1 Modes and Menus page for those details.

Super High-Res Electronic Viewfinder

The keys to the Panasonic G1's exceptional EVF performance lie in two technologies. First, the active element of the display is an LCOS (liquid crystal on silicon) chip. This technology actually controls the state of the liquid crystals by electric fields projected through the silicon. This means that all the active circuitry can be on the back side of the chip, so the entire display surface is active: With no dead areas between pixels, light is reflected from the entire surface, so there are no distracting black areas surrounding each pixel.

Because the LCOS chip is reflective, you generate an image by bouncing light off its surface, rather than by passing light through it as in a conventional transmissive LCD. It turns out that LCOS chips can also change states very rapidly; fast enough that you can display the red, green, and blue color channels in very quick succession with no blurring or crosstalk between the color channels. Human persistence of vision blends these together into a single pixel displaying a full range of color. Looking into the Panasonic G1's EVF then, you don't see individual red, green, and blue stripes or dots, you just see a surface of continuous color. To be fair, this isn't a new innovation with Panasonic: The original Minolta A1 digicam used similar technology, but its EVF had much lower resolution, and considerably lower image quality overall. The concept has certainly been seen before, but the Panasonic G1's EVF seems to take the technology to another level.

Light for the G1's EVF comes from a trio of red, green, and blue LEDs: They strobe on and off in very quick succession (180 times a second, for a 60 frames/second overall refresh rate), as the LCOS chip displays the red, green, and blue image planes in lock-step. In playing with the G1, I expected to see some tearing of the display, or perhaps a rainbow effect if the subject moved rapidly, but actually saw very little evidence of this in my limited time with the camera.

The second key technology in the Panasonic G1's EVF is a holographic diffraction grating that's curved above the LCOS chip. This optical element reflects the RGB light from the LED array onto the LCOS chip's surface, but lets the light reflected from the imaging chip pass through unobstructed, out the eyepiece and to the user's eye. Other technologies could be used to make a reflective imager work in a viewfinder, but the holographic grating allowed Panasonic's engineers to squeeze the whole assembly into an incredibly compact package.

As befits its heritage in the high-end broadcast TV field, the Panasonic G1's EVF has impressive specs. It has unusually high resolution for a camera EVF, displaying 800x600 (SVGA resolution) full-color pixels. (A total of 480,000 full-color pixels.) Panasonic equates this with 1.44 million dots in a conventional display, as most displays would need three separate dots for each full-color pixel. In practice, the effective perceptual equivalent of 480,000 full-color pixels is more like 960,000 RGB dots, but the fact remains that this is a very high-resolution, very smooth-looking display. As noted above, the G1's EVF also refreshes at 60 frames/second, so there's very little flicker or tearing with moving subjects.

Thanks to its LED illumination, the Panasonic G1's EVF also has a very wide color gamut, covering 100% of the NTSC color space, an unusually broad range for a camera display. As you'd expect, it also covers 100% of the field of view of the camera, since it's getting its image directly from the camera's image sensor. Finally the the EVF's optics give an effective magnification of about 0.7x relative to a 50mm lens on a 35mm camera. This is about the same viewing magnification as found on most higher-end SLRs. In practical terms, it means that with a 35mm lens attached (roughly equivalent to a 50mm lens on a 35mm camera), the image in the viewfinder will match what you're seeing through your other eye. This makes it easier to shoot with both eyes open, so the eye not looking through the viewfinder can give you much better peripheral vision of subjects about to come into the field of view, etc.

All in all, the G1's electronic viewfinder clearly sets a new quality standard for EVFs in digital cameras.

Panasonic G1 Intelligent Auto Mode: "Trust IA"

The Panasonic G1 has the usual PASM set of exposure modes (Programmed, Aperture priority, Shutter priority and Manual exposure), plus Auto, but also offers what Panasonic calls Intelligent Auto. Panasonic introduced IA mode on their digicams a year or two back, and has continued to refine it since then.

The idea behind Intelligent Auto is really what "Auto" mode should have been all along: The camera does its utmost to figure out what sort of subject you're shooting and the conditions you're shooting under, then adjusts its settings to deliver the best picture possible. This turns out to be a lot easier said than done, though, given how easily most camera's Auto modes are thrown off by backlit shots, incandescent lighting, sunsets, even macro subjects. (Why should we have to tell the camera to switch to macro mode? Can't it figure out that the subject is too close for normal focusing?)

In the Panasonic G1, the engineers responsible for exposure and white balance have continued to extend the camera's intelligence in figuring out what it's being asked to do. Intelligent Auto in the G1 has six sub-functions that look at different aspects of the image being viewed, making its decisions accordingly. These include:

• Shake Detection - Mega O.I.S. turns on automatically to reduce blur from handshake.
• Motion Detection - When the camera detects a moving subject, Intelligent ISO Control boosts the ISO setting to reduce blur from subject motion.
• Scene Detection - Intelligent Scene Selector recognizes common shooting conditions such as Night Scene, Macro, etc., and adjusts white balance, exposure and focus accordingly.
• Face Detection - If the camera detects faces in a scene, it judges focus and exposure based on them, rather than surrounding objects.
• Subject Detection - AF Tracking can automatically lock-on moving subjects.
• Light Detection - Intelligent Exposure pulls details out of shadows.

Early versions of IA were only a bit better than conventional Auto mode, but with the G1, it's really possible to "Trust IA," as Panasonic's marketing slogan suggests.

Fast (for contrast-detect) Autofocus on the Panasonic G1

When I first heard of the Micro Four Thirds concept, my initial reaction was concern over whether shutter lag wouldn't be a problem, given the sluggish response times of conventional point & shoot digicams. Without a mirror assembly, there's no place to put a phase-detect autofocus sensor, and it's those sensors that account for much of the responsiveness in conventional SLRs. Without a mirror box, Micro Four Thirds cameras would have to resort to contrast-detect AF, generally a much slower focusing process.

You can imagine my delight, then, when I picked up the G1's prototype, pressed the shutter button and... the camera quickly focused and snapped the picture! It was by no means instantaneous, and I didn't have any way of measuring the exact lag time, but the camera certainly felt responsive. I'd say it isn't as fast as a higher-end DSLR, but is certainly in the ballpark relative to entry-level models; exactly the part of the market the Panasonic G1 is aimed at.

While speed has been problematic in the past, contrast-detect AF systems win big time over phase-detect ones when it comes to focus accuracy. Panasonic says that typical phase-detect AF systems can focus to within +/- 100 microns at the sensor plane, while contrast-detect systems routinely achieve accuracies twice that high, on the order of +/- 50 microns. Beyond basic accuracy, though, the fact that the G1's contrast-detect system will always be judging focus based on what the main imaging chip sees means that it will never have a problem with front- or back-focus, a common issue in conventional digital SLRs.

The contrast-detect approach also lends itself to much greater focus flexibility, including many more focus areas, movable focus areas, face detection and enhanced subject tracking. The Panasonic G1's default focus system looks at 23 areas across the frame before deciding what to focus on. Alternatively, you can switch to Advanced 1-point AF mode and move a single focus point anywhere in the frame you want it. That single point can also be a spot, normal-sized, large, or extra-large area. Likewise, face detection can recognize a number of faces in the scene, focus on the nearest one, and then use that area to also set exposure. Standard fare for digicams, but something SLRs can only do in Live View mode - And then often somewhat slowly.

The Panasonic G1's AF system also has a handy AF tracking option: Once you've locked onto a subject, it can optionally track the subject wherever it moves in the frame. I can see this being handy for people taking pictures of wiggly kids, pets, or other subjects that rarely cooperate by staying in one place for any appreciable time.

We're hoping to get our hands on a prototype of the Panasonic G1 soon, so we can test its shutter response in the lab and see just how good it is. I'll be surprised if its shutter lag is much over 0.4 second though, as it really did feel quite responsive when I played with it, however briefly.

Panasonic G Series Lens System

Because of the changes in flange diameter and back-focus distance, the new Micro Four Thirds system will require its own lens line. With the G1, Panasonic has announced the first two of what they promise will grow to become a broad line of lenses in the years to come.

Two things immediately struck us upon seeing the Panasonic G1 and its lenses for the first time. First of all, these lenses really are a lot smaller than equivalent ones in the current Four Thirds world. The second thing that caught our eye were the lens flanges: The two lenses introduced with the G1 both feature solid metal mounting flanges, a relative rarity in entry-level removable-lens cameras, and something that speaks well of their build quality.

The first two lenses in the G-series lineup are a 14-45mm f/3.5-5.6 image-stabilized zoom and a 45-200mm f/4.0-5.6 tele zoom that also sports Panasonic's excellent Mega OIS stabilization. On the G1, these lenses will be equivalent to 28-90 mm and 90-400 mm lenses on a conventional 35mm film camera. That's a really excellent range, and the image stabilization will be particularly welcome when you get out to the 200mm (400mm equivalent) end of the tele zoom.

Coming Attractions
While not giving any specific delivery dates, Panasonic is promising at least three new lenses next year (2009), a 7-14mm f/4, a 20mm f/1.7 super-compact prime (great for street photography!) and a long-ratio 14-140mm f/4-5.6 OIS "HD" lens. - The "HD" indicates that this lens will support on-the-fly focusing during HD movie recording, on a camera that will also be announced sometime in 2009.

It's important to note that all the G-series lenses from Panasonic support the G1's contrast-detect autofocus system, while some current Four Thirds system lenses will not.

Using your current Four Thirds Lenses

This brings us to the issue of using current Four Thirds lenses on the new Micro Four Thirds system. It is indeed possible to use all your old glass, by virtue of the MA1 mount adapter, although there may be limitations with some lenses.

The shots above show the MA1 adapter by itself and attached to the 14-50mm lens that shipped as the kit optic with the Panasonic DMC-L10 SLR. The adapter is quite easy to use, just attach it to the lens and then attach the combination to the camera. Since all it's doing is adapting between the different flange sizes and adding 20mm of increased back focus distance, the mount adapter needs no optics in it, so it has no effect on image quality, lens speed, or any other optical characteristic.

That all sounds great, so what's the limitation? It turns out that not all lenses are able to move their elements quickly enough to work with the G1's contrast-detect autofocus. Normal phase-detect AF systems are fairly forgiving of focusing speed, because the correct focal distance setting is determined independently of the lens elements' motion: The camera looks at the subject, calculates the correct focal distance, commands the lens to move, and then snaps the shot once the lens reports back that it's moved to the correct setting.

With contrast-detect autofocus, though, the lens has to move multiple times, and must come to rest before the camera can take each "look" at the subject, to determine whether the focus is better or worse than it was at the previous focal setting. In order for the overall focus cycle to be performed quickly, the lens needs to be able to shift focal settings very quickly, multiple times per second. This is a demanding requirement, and not all lenses are up to the challenge. Olympus offers contrast-detect AF on some of their recent SLRs, but the feature only works with a few lenses that have focus motors both strong and fast enough to move the lens elements very quickly. Other manufacturers offer contrast-detect AF that works with any of their lenses, but at the cost of very slow AF times. (It's for this reason that Nikon refers to the contrast detect AF option in their SLRs as "tripod mode.")

So, while some current Four Thirds lenses will work just fine on the new Micro Four Thirds system, with full support for AF operation, other lenses will be reduced to "guided manual" focus, in which the user will need to adjust the focus setting, looking to either the viewfinder (less accurate) or the camera's focus indicator (more accurate) for focus confirmation.

Panasonic G1 Live MOS Sensor

Apparently, one issue that led to the choice of a greater back focus distance in the original Four Thirds specification was the problem of self-shadowing on CCD sensors. CCDs have a very significant three-dimensional surface structure, so the tall walls of metallization and insulation around each pixel's active area can shadow portions of the pixel's surface if the light arrives at an angle too much off vertical. Designing lenses with a greater back focus distance helps reduce the angle of the light rays around the edges of the sensor, so this was the direction taken by the original Four Thirds committee.

Besides being one of the world's largest CCD manufacturers, though, Panasonic also makes NMOS sensors (which they call Live MOS). These have much less three-dimensional structure on their surface, and so are less subject to self-shading, making this technology a key part of the Micro Four Thirds system. With a shallower surface structure, you can bring the back of the lens much closer to the sensor's surface, without having problems with self-shadowing. Other desirable characteristics Panasonic claims for their Live MOS technology are "the superior image quality of a CCD sensor and the low power consumption of a CMOS sensor" -- a claim we'll be putting to the test.

The Panasonic G1 uses a brand new 12-megapixel Live MOS sensor, incorporating several improvements over prior designs. The new chip has a redesigned cell layout, with more active area and therefore higher sensitivity and lower image noise for a given pixel size. It also sports four channels for data readout, necessary to deliver the 60 frame/second Live View images and equally fast autofocus measurement/adjustment cycles required to make the Lumix G1's contrast-detect autofocus so responsive.

We'll see how a production sample of the Panasonic G1 fares in our laboratory tests, but I can say now that a few shots I snuck with the prototype at ISO 1,600 looked surprisingly clean; especially for an early-stage prototype. The more I see of it, the more interesting the G1 and the whole Micro Four Thirds concept looks: We'll be very eagerly awaiting the availability of a production sample, so we can test its performance and share the results with our readers.

Panasonic G1 Dust Reduction

Dust reduction systems are all the rage these days, and for good reason: Dust is public enemy number one when it comes to removable-lens cameras. If a speck of dust got onto a piece of film, one frame would have a spot on it. If a speck of dust gets onto a digital sensor, though, every frame will have a spot. In our experience, dust removal systems are only a partial help: You're still going to need to wet-clean your sensor from time to time. A good dust-removal system is definitely some help, though, lengthening the interval between manual cleanings.

With the G1, Panasonic has taken dust removal technology up another notch. The shot at right shows the Live MOS sensor mounted behind the cover glass and dust-removal assembly. The piezoelectric dust-removal actuator is the black ring that surrounds the sensor. What's significant here is that the piezo actuator surrounds the imaging area, rather than being restricted to just a small patch on one or two sides. Panasonic claims that they're the first company to design a dust-removal unit with the piezo actuator fully surrounding the cover glass. This provides much more uniform and stronger shaking than conventional systems. The increased area of the actuator also let them increase the maximum shaking frequency to 50,000 cycles/second, up from 30,000 cycles in earlier models. The combination of higher frequency and more uniform application of the vibrating force should translate into a noticeably more effective dust-removal system.

Venus Engine HD "Duo"

Next to its image sensor and lens, a digital camera's image processor is its most important component. Image processing is extremely compute-intensive, and noise reduction in particular gobbles CPU cycles like there's no tomorrow. Then of course, there's frame rate: A 12-megapixel sensor generates a lot of data, so it's a challenge to digest all that and keep up with a three frame per second continuous shooting speed.

The Panasonic G1 not only uses the latest version of the Venus processing engine, the Venus IV, but uses a dual-core Venus chip as well. This is a huge increase in processing power relative to previous Panasonic cameras, and the Panasonic execs seemed rather excited by the dual-core Venus IV. For our part, we're looking forward to seeing the G1's images, and hoping that the greater processing power will translate into improved noise performance, without loss of subject detail. Noise processing aside, the Venus IV is impressive just for its ability to move image data around: With a fast SD card, the Panasonic G1 can capture full-resolution JPEG images continuously at 3 frames per second until the card fills up.

Another nice feature of this latest Venus chip is its support of HDMI output, for direct connection to HDTVs for image viewing. With HDTVs appearing in more and more homes, the prospect of producing HD-quality slide shows directly from your camera is increasingly appealing. The shot above shows the HDMI cable plugged into the side of the G1. (Note that the camera's connector is the mini-HDMI variety: You'll need to find a mini-to-standard HDMI cable to make the connection.)

Panasonic DMC-G1 Pricing and Availability

In the US, the Panasonic G1 will be available body-only, or in a one-lens kit (kit contents shown above), with the 14-45 mm lens included. Internationally, there'll also be a double-lens kit available, including the 45-200 mm lens as well, but it appears that that variation won't be coming to the US, at least not initially. Olympus has had great success in the US market, selling two-lens kit versions of its Four Thirds SLRs at attractive prices. I suggested to the execs present that Panasonic consider bringing the two-lens version to the US as well. We'll see if they follow my advice or not. ;-) I think the two-lens kit would be very popular with the stereotypical "Soccer Mom," as the image-stabilized tele zoom would make for great shots of kids' sports.

The Panasonic DMC-G1 will be on retail shelves by mid-November, 2008. The suggested retail price is US$799.95, which includes the LUMIX G VARIO 14-45mm F3.5-5.6 ASPH MEGA O.I.S. kit lens. The LUMIX G VARIO 45-200mm F4.0-5.6 MEGA O.I.S. telephoto lens will also be available in November, at a suggested retail price of US$349.95.