One of the reasons I invested heavily in the Olympus system was the E-3 body. The E-3 body is built of molded magnesium, has a bright full-frame optical viewfinder with 1.15 magnification, image stabilization in the body, an articulated LCD with live view, is dust- and splash-proof, and has IMHO one of the best 4/3rds sensors on the market.
Full Frame Viewfinder
The viewfinder, more than just about any other feature, was the deal-maker for me. It's an optical penta-prism design that shows 100% (or nearly 100% according to the ad copy) of the image that will hit the sensor, while providing a magnification factor of 1.15x. This helps produce a bright, sharp viewfinder that's very easy to focus with, especially compared with my older E-300. Don't get me wrong. I love that E-300 and still continue to use it, but the E-300's viewfinder, a porro-based penta-mirror, is darker and at times difficult to use, especially in low-light situations. The E-3 in comparison is blindingly bright.
The E-3 also comes with a built-in eyepiece cover. The eyepiece is closed when using Live View (more about that below), where it's closed to avoid exposure inflation due to light coming in through the eyepiece.
All is not perfect harmony with the finder. A minor nit is the clip-on eye cup. It can be easily knocked off; I've spent more effort than I care to admit noticing it's gone and having to re-trace my steps to find and put it back on again. I've lost the original that came with the body; I ordered its replacement and an additional spare (at $8 a pop).
Body and Environmental Protection
The body is constructed from injection-molded magnesium alloy, wrapped in fiber-reinforced plastics and rubber-like coverings. It's the biggest body you can purchase in the Olympus line, and the heaviest. In spite of being the biggest and heaviest, it's not too big nor too heavy for me. The size and shape of the body fits my hand like a glove, especially when I slip my hand under the attached AS-GS3 grip/hand strap; it feels like one with my hand. The body is "balanced" with an HLD-4 vertical grip/battery holder bolted onto the bottom. Over the past ten months I've learned where everything is (reading the manual, practice, and with the occasional questions on forums about certain features). I'm quite comfortable with operating the camera, and the more I use it the more I grow to like it.
In spite of how well the whole assemblage feels to me, there is a problem with the body and grip combination mounted on a tripod. I own a Benro A-269 M8 tripod. I discovered during a Labor Day weekend shoot that with the E-3/HLD-4/50mm macro mounted on the tripod head and with the camera on, that moving the entire assemblage (camera + gear + tripod) will cause enough of a flexure between the grip and the body that the camera momentarily looses electrical connectivity with the grip and causes the body to reset itself. I'd read of this issue before. Once I encountered it I simply turned off the camera before picking everything up to move it. It's the most annoying quirk in an otherwise excellent system, and the obvious work around is to turn off the camera before you move it mounted on the tripod, but that problem shouldn't be there. I have heard that the E-30 and HLD-4 combination do not have this issue.
The sensor measures 17mm by 13mm (hence the aspect ratio of 4/3) and is capable of 10mp resolution. There have been more than enough reviews of Olympus DSLR models and their various sensors; I'll let you hunt them all down. However, if you want the definitive reason why Olympus developed the 4/3 sensor, you can read about the benefits of the four thirds system here.
While there are now higher resolution sensors (12.3mp) in newer models (E-30, E-600/620, and E-P1), the resolution, dynamic range, and noise are more than adequate for my needs. I have discovered that the range from ISO 100 to 800 produces excellent results. In a pinch, and keeping prints and images down to 5x7, I can shoot all the way up to ISO 3200 and get very good results.
The E-3, like so many current Olympus models, has image stabilization built into the body via the sensor support assembly. This is one key advantage over other systems that insist on adding image stabilization to the lens; with a contemporary Olympus body (E-5x0, E-6x0, E-30, and E-P1) every single lens, from the least expensive to the most, benefits from image stabilization.
Articulated LCD and Live View
This was a feature I didn't appreciate immediately; it's usefulness to me grew with time until I find it almost indispensable, especially combined with live view and macro work.
I own the Olympus 50mm f/2 macro. When used for its primary purpose, macro photography, its performance is second to none. The best way I found to use it with the E-3 is to mount the E-3 on a tripod and then rotate the LCD out and enable live view, using the now-comfortably positioned LCD to compose and critically focus the image. I can not only immediately view what I'll eventually capture, but I can also view the effects of aperture, exposure compensation, and color temperature selection as well. I'd much rather take the time setting up a good shot rather than blindingly shooting away.
The only problem with near-perfect feature is the heat generated by the sensor in live view. While shooting outdoors in direct sun one hot Florida day (temperature in the mid-90's), the sensor overheat indicator illuminated on the LCD. I shut the camera down momentarily (it would have shut down on its own) and moved out of the direct sunlight for several moments before turning the camera back on and continuing. In the future I'm going to put up a small umbrella to shade the camera if it's out in the direct hot sun. That's the only time I've ever had a heating problem. Other than that, it's been a stellar feature.
In-body Image Stabilization (IS)
A key feature that I have found useful in low-light situations is the in-body IS. Unlike other manufacturers that add IS to their lenses (such as Nikon, Canon, and Panasonic), having the IS in the body means that any lens attached to the body becomes image stabilized. To give you an idea of how useful IS can be, consider the image of Ruby and Max to the right. This image was shot, hand held, with the 12-60mm at 60mm, f/4 (wide open), ISO 800, at 1/5 second. The image is sharp enough that you can easily see the stitching on the sofa as well as details on the dogs (Ruby's eyelashes, for example).
IS is best for those shots in low light where the subject is fairly static; active subject will blur anyway due to their motion, which negates the reason for turning it on. Most of my experience has been with IS1. I've tried IS2, but I've not been too satisfied with it, and prefer to just turn off IS and pan with the subject (like I did in the 'old days' with film). And there have been several instances, specifically with flowers blowing in a breeze, where IS caused the image to be blurrier than if I had just left it off. In all cases I was shooting outdoors during the day in direct sun and the flowers were in sunlight.
Once again though, thoughtful application of the feature can return excellent results.
Oh, and one other peculiarity of the IS feature. If you leave it enabled and turn the camera off, the camera will emit a low buzz or 'rattle'. This is the sensor calibrating itself. It is disconcerting to hear it when it goes off, and I have never quite gotten used to the noise. Call me silly but I've learned to automatically turn it off before turning off the camera.
Complaints aside, I consider the E-3 an excellent camera. The E-3 has opened up a whole new world of photography for me with respect to the E-300, and has helped to build upon the capabilities of the Olympus system I first discovered with the E-300. The E-3 combined with High Quality lenses such as the 12-60mm, 50-200mm, and 50mm has produced impressive results for me and for others for whom I have taken photographs. I'm very glad I purchased the camera, and look forward to adding new bodies and lenses to the system.