The excitement from the Olympus PEN E-P1 
launch is starting to die down, and people are deciding weather or not they actually want the camera. Most of the specs look great, but let's take a closer look. Sure, I haven't used the camera yet, but that never stops some camera pundits (rhymes with Schlockwell) from making 'reviews'. Basically, I'm going to step through what we know about the camera to help myself (and maybe you) decide about pre-ordering it.
The LCD
Like it or not, the primary method of interacting with this camera will be the LCD screen. The optical viewfinder for the 17mm lens is a great idea, but it only works with one lens and doesn't let you know what the camera is focusing on. You'll still need to use the LCD to review your photos, use many of the camera's features (in-camera RAW development, etc.) and change your settings. This is why it's so baffling that Olympus chose to use a behind-the-times 230k-pixel 3-inch screen while the competition's screens have AT LEAST twice the resolution. The only reasons I can think of are cost-cutting or battery life. If it's the former, the center of the camera's interface a terrible place to skimp. If the latter, I can't imagine it saves too much power, since the back-light (which is the main power draw) would still be the same size.
Now the LCDs in Oly's DSLR offerings are pretty good as low-pixel-count ones go, so this LCD should still be better than the appalling one found in the DP2 (which has the same pixel count). I recently used a 230k-pixel SD880IS 
alongside a 5D Mark II 
, which has quadruple the resolution on the same size screen, for a prolonged period of time. While the 5D2's screen is incredibly good, I rarely found the quality 230k-pixel LCD of the SD880 lacking. Initial reports say that the screen is excellent for it's resolution, but viewability (and manual focusing) become very difficult in bright sunlight. Thus, the E-P1's LCD choice is unfortunate here, but I don't think it'll be a deal-breaker.
Performance
If the E-P1 is to be the DMD (decisive moment digital) of Mr. Johnston's dreams, it will have to very snappy in operation. I'm not worried about shutter lag, since all the previews say that it's mostly non-existent. Power-up and shut-down times seem good as well. 3fps and a big RAW buffer are also very nice. Since the processor in the camera is very similar to the ones in the latest Olympus DSLRs, we can assume that general camera performance, SD write speeds, etc. will also be very good.
The biggest concern here is the autofocus system. Let's see what initial previewers have had to say:
My time with the camera was too limited to say anything concrete about the autofocus system, except that it was not obviously slow in any way. More testing definitely needed there.
- Eamon Hickey on T.O.P.
The E-P1 uses essentially the same focus system as cameras such as the E-620, meaning that it feels sluggish even compared to most compacts (that said, we're playing with a very early IP (initial production) unit here - without the final firmware - so will reserve judgment until we've got the finished product).
- DPReview's Preview
The live view experience is better than on most digital SLRs, but not as good as I've seen. The camera uses the Live MOS sensor to focus (using contrast detection), and it's faster than on Olympus' D-SLRs, but the Panasonic G-series twins and the Sony A3xx series are all noticeably faster.
- DC Resource's Preview
I can attest to the fact that the Panasonic G1 
's AF speeds are excellent. Not nearly as fast as, say, and EF 85/1.8 on a Canon 50D 
, but certainly good enough for the vast majority of uses. Panasonic has not passed on the secret of super-fast contrast-detect AF to Olympus, and this might be a killer. Slow autofocus (among other things) is what killed the Sigma DP2 for so many people. From the comments above, the E-P1 will lie somewhere between the DP2 and the G1. That may or may not be good enough. It's important to note that firmware 1.0 (the one at least some previewers used) will not be the final production firmware version. We can only hope that they can considerably speed up AF before release. One silver lining is that contrast-detect AF can be used as AF-confirmation when using manual-focus lenses.
The m43 Lenses
The 17mm f/2.8 
pancake. This is the lens many have been waiting for. A nice 35mm (-ish) FOV and a fast (-ish) lens in a very small package. Many rangefinder people have been excited about the combination of this lens and the optical viewfinder 
. Unfortunately, the lens isn't all it's cracked up to be. Take a look at these samples from DPReview taken with the 17/2.8. Note the massive amount of chromatic abberation in the first photo, which is stopped down to f/6.3. The short lens-to-sensor distance, which typically requires light to hit the sensor at more of an angle, may be the culprit here. More telecentric designs like those found in the DP2 and most 4/3 lenses tend to have less CAs. None of the 17/2.8 samples I've found are taken with an aperture wider than 6.3. Update: there are now a couple shots at f/2.8: This one and this other one. The lens seems reasonably sharp at F/2.8 and very sharp by f/6.3. If a lens is going to be my main walkaround prime, it has to be exceptional, not just pretty good. The latest f/2.8 samples do seem to suffer from less CAs than some of the other samples I've seen, even in the first shot (backlit headshot). There are very few primes for the 4/3 system, and only this one (so far) for m43. The other 4/3 primes, especially the Olympus 50mm f/2.0 Macro 
macro and the expensive Panasonic 25mm f/1.4 
have excellent reputations, but it seems like the 17/2.8 is not quite there.
The all-important kit lens, the 14-42mm f/3.5-5.6 
. On paper this is very similar to the G1's kit (very good) kit lens. The coolest feature of this lens is its ability to collapse down much smaller than at its shortest focal length. This allows the kit to stay much thinner than the competition. It is still somewhat wider around than the pancake, but impressively compact for a kit lens. The samples from this lens also show far less chromatic abberations than those taken with the 17/2.8. The build quality will likely be like that of other cheap Olympus kit lenses, but that is still better build and image quality than most $100 kit lenses on the market.
Panasonic also has 4 m43 lenses of their own that are all compatable with the E-P1. The ultrawide 7-14mm f/4.0 
, the G1 kit 14-45/3.5-5.6, the telephoto 45-200/4.5-5.6, and the GH1's 14-140 "HD" lens. All of the current Panasonic m43 lenses other than the ultrawide offer optical image stabilization, but that apparently won't work on the E-P1, which has its own stabilization system. Initial reports on the 14-140 say it's not so great for stills, which isn't surprising given the 10x zoom ratio and the fact that it's focused on videos. Either way, the 14-140 would look very large and unweildy on an E-P1. The 14-45 kit seems redundant given Oly's very similar and smaller kit lens. The telephoto and ultrawide lenses could be interesting options for E-P1 users. They are still large, but offer fields of view not yet available from Olympus... at least not in native m43 mount. As with any new system, lens choices for m43 are currently somewhat limited, especially as far as fast prime lenses are concerned. Enter the adapters...
"Alternative" Glass
Since the flange-to-sensor distance of m43 is so much less than other interchangeable-lens systems, almost any lens can be adapted to m43 cameras. There are official and 3rd party adapters covering Four Thirds 
, Olympus OM 
, and Leica M, Leica R, Canon FD, and more. Much has been written about using adapted lenses (mostly M-mount as they are smaller than SLR lenses) on the G1. I'd love to try the ZM 35/2, FD 24/2, or even an LTM Jupiter-9 85/2 on the E-P1. Many who have tried it ended up sticking with the kit lens as they didn't like the hassle of stopping down manually, etc, but I think it would be interesting for a while at least. There are, however two HUGE problems with adapted glass on the E-P1.
First and most obviously is the smaller sensor on the m43 cameras. You get an effective field-of-view of a lens with 2x the focal length. Since most adapted lenses will be designed for 35mm film, this will make it difficult to cover the wider end of FoV range. That 35/2 becomes a 70/2, and even an "ultrawide" 15/4.5 becomes a 30/4.5. The flip side of this is that a) you only use the center (usually best) part of the image circle, and b) you can get compact long lenses. A 50/1.4 becomes a 100/1.4 portrait lens with in-body IS and more depth-of-field (given the same framing) than a 100/1.4 on 35mm.
The other problem with manual-focus lenses on the E-P1 is the act of focusing. Since the E-P1 has no viewfinder, you have to hold it out in front of you to see the screen. I have tried manually focusing MF lenses using live-view at arm's length on the 40D and the 5D markII, and it is not fun. It works well enough if you have plenty of time to set up your shot, but otherwise it's clunky. The low-res screen of the E-P1 doesn't help either. The G1's eye-level viewfinder would probably be better for adapted lenses, but Panasonic's cameras don't offer in-body IS and probably won't anytime soon. Fortunately, the E-P1 does offer a feature that zooms in the LCD while you're focusing your MF lenses. Update: It turns out that the auto-zoom feature in MF or MF+AF mode only works with lenses that can tell the camera the focus ring is being turned. That means you only get the auto-zoom feature with 4/3 or m43 lenses. You can still magnify the view, but you'll have to flip in/out of the magnified view manually (zoom, focus, un-zoom, compose, shoot).
Neither of these disadvantages apply to (Olympus branded at least) 4/3 lenses, which will all eventually have their firmwares updated to AF with the E-P1.
Image Quality
Putting this section near the end of the article may make it seem like I don't care about IQ, but the fact is we basically already know what kind of images we can expect from this camera. The same 12mp sensor has already been reviewed in several cameras (Panasonic G1, Olympus E-620, Olympus E-30) and has proven itself to be a solid performer. 4/3 and now micro 4/3 (m43) have always lagged about 1 stop behind the APS-C crowd in terms of noise control, but new noise-reduction algorithms make ISO1600 seem pretty useable on these latest cameras. Even the ISO6400 shot I saw looked decent, mainly due to the good control of chroma noise. Olympus has a reputation for excellent image processing, and the E-P1 is supposed to have a weaker anti-aliasing filter than the Oly DSLRs (due to the new, more powerful, image processor being able to get rid of moire). The camera will be correcting distortion, but it remains to be seen if it is done in the RAW files or not. Hopefully it will not happen until you process the files. My main concern is some serious shadow noise in the samples, even at base ISO (200), but it may be due to some post-processing issues. I'm not expecting 5DmarkII quality, but it will still be miles ahead of any small-sensored camera.
Design
The aluminum (top / bottom) and stainless steel (sides) camera comes in white / beige or...
silver / black. Even with the odd-looking extended kit zoom, the camera is very handsome. Olympus is clearly trying to appeal to "step-up" users that I mentioned in my G1 post. Many of the people who don't want the bulk of DSLRs are women, so the more "feminine" looks of the white model were a smart (and nice-looking) move. It's interesting that the E-P1 weighs more than the considerably larger Panasonic G1. This is probably due to the metal build. It is still, however, a decidedly lightweight camera.
This is evidenced by the familiar P&S-like controls on the rear of the camera. All-in-all, the design seems very well laid out. I'd prefer a 1-front / 1-rear dial configuration to two rear ones, but that's probably nitpicking. Many people are disappointed that there's no black-on-black option. I personally don't care too much, but it would be nice to have I suppose.
The only problem I can see with grip-less cameras is that even a pancake lens sticks out at least 1cm, so the thickness of the camera with a lens is never any less than the thickness at the mount + 1cm. This means that the grip area could always be a little thicker, which would accommodate a larger and longer-lasting battery.
Buy now, or wait?
If you've made it through this post still wanting this camera, there's one more issue to think about: more interchangeable lens digital (ILD) cameras set to release sometime in 2009. I say ILD instead of m43 because another similar system is supposed to be coming from Samsung (the NX system).
The Samsung NX system will use larger APS-C sensors with a 1.5x crop factor, so that system might be better for those who mainly want to use adapted lenses. However, the bigger sensor necessitates bigger bodies and bigger lenses, so you aren't likely to see an NX camera the size of the Pen.
Panasonic has announced that their long-awaited and much-hyped 20mm/1.7 will be available this Fall. There will probably also be a smaller Panasonic m43 camera on the way. The word is they started with more conservative DSLR-like design with the intention of getting more Pen-like in the future. The G1 is also a very viable competitor. It's considerably larger than the E-P1, but still a very compact and comfortable camera and very affordable. It would be a good choice for those who insist on an EVF or who like high-res articulating LCDs (which are great).
Olympus itself plans to release an m43 camera with an EVF:
We are now preparing for a future product with an EVF. But for this product [E-P1] we were concentrating on small size.
- Akira Watanabe, from a DPReview interview.
The quote does, however, imply that the EVF-equipped Olympus would be considerably larger than the E-P1. It almost seems like the E-P1 and G1 would compliment one another perfectly.
So, what'll it be?
Well, the E-P1 looks like a great camera with a couple of flaws. Namely: the low-res LCD and the sub-Panasonic focusing speeds. I almost kept the DP2 with it's WAY worse LCD and WAY slower focusing, and the E-P1 is only $150 more than the DP2. I think the E-P1 is a "buy" for me, so the real question is which kit to get:
I have some doubts about the quality of the 17mm prime, and f/2.8 isn't really fast enough for me. I'd also like to avoid paying $100 for a viewfinder which will make the camera larger and which I probably wouldn't use all that often. It's too bad that the lenses are $50 when bought with the camera yet $230 when bought alone. I think the 14-42 kit is the best option for now. Hopefully the Panasonic 20mm f/1.7 will be good enough to be my fast prime for this lens. Now to find a good M-mount to m43 adapter...
A Few Links:
for $899
more illicit-looking, but the build-up and pay-off of the E-P1 announcement has been incredible. The long and frenzied threads over at 
