EDITORS NOTE:All underwater images in this article were shot with the Olympus E-PL1 camera, Olympus PT-EP01 underwater housing, and the Zen WA-100 dome port. Shooting locations included our recent Cocos Expedition, the Digital Shootout, and our Backscatter staff training trip in the Channel Islands.Introduction to the Micro 4/3 System Olympus and Panasonic launched the exciting Micro 4/3 system of cameras in the summer of 2008, and today the system's promise is finally coming to fruition for underwater use. The concept of the system is simple: use camera bodies that support a wide range of interchangeable lenses, but are much smaller than SLR cameras due to the removal of the viewfinder mirror and prism. These new compact SLR cameras lack a traditional viewfinder, but offer high quality interchangeable lenses and use a high resolution LCD screen to compose the shot. This new breed of compact cameras go by the unusual nicknames of mirrorless or EVIL (Electronic Viewfinder Interchangeable Lens). Together, Olympus and Panasonic have launched a wide variety of mirrorless camera bodies and lenses, and best of all, these lenses are interchangeable between brands. Panasonic lenses can be used on Olympus bodies, and vice-versa. The Olympus E-PL1 camera body is surprisingly small and compatible with interchangeable SLR lenses from Olympus and Panasonic. At the time of this writing, the basic body and 14-42mm lens kit is only $499.The Olympus E-PL1 camera body and Olympus PT-EP01 underwater housing.Meet the Olympus PENHoney - I shrunk the SLR . . . and the price! Olympus brought considerable excitement to the photography world earlier this year when they announced the third model in their line of PEN cameras, the E-PL1. Not only is the E-PL1 the smallest micro 4/3 camera body to date, it's also the most affordable. The Olympus E-PL1 has advanced features for such a small camera. The E-PL1 is a 12 megapixel camera, capable of shooting three frames per second up to 10 raw frames, and features 720p video at 30 frames per second in AVI Motion JPEG format. It features a high-resolution LCD, useful for framing images with the camera at arm's length and dedicated physical dials and buttons for important controls. Advantages of the PEN system over smaller point & shoot cameras So what is so special about the micro 4/3 system? Micro 4/3 sensors are much larger than the sensors found in compact cameras. For example, the E-PL1's sensor is nearly 5 times the size of the one found in the Canon G12. This has a significant impact on image quality, especially at higher ISO settings. For low-light situations, the E-PL1 produces less noise (smoother images) than other compact cameras with similar megapixel ratings because its sensor has so much more area with which to collect light. Furthermore, the E-PL1 handles more like a low-end SLR than a high-end compact. Autofocus is quick, shutter lag is non-existent, and the camera is ready to fire again immediately after shooting an image. As it is built upon a foundation of interchangeable lens, the E-PL1 offers an opportunity to invest in a future-proof system. When future camera bodies offer improved image quality, the optics used with the E-PL1 today will still shoot sharp images and work in your next underwater housing in the future. This macro shot was taken with the Panasonic 45mm macro lens. The micro 4/3 system allows you to choose the best lenses from each manufacturer as cameras and lenses are interchangeable among brands.Olympus PT-EP01 Underwater Housing Features At first look, the Olympus PT-EP01 has a surprisingly high quality feel and function for a plastic camera housing. It's a fraction of the weight of larger SLR housings making it easy on the arms to carry the unit topside. The housing allows space for the optional electronic viewfinder, but due to the high resolution LCD screen on the back of the camera, we found the electronic viewfinder unnecessary. Unfortunately this additional viewfinder space makes the housing taller than it needs to be, but the extra air space gives buoyancy to the system and makes it near neutrally buoyant in water and easy to swim and shoot with one hand. Despite its small size, dedicated dials and controls on the Olympus PT-EP01 Housing allows for better ergonomics and quicker access to key controls over the other micro 4/3 and mirrorless cameras on the market. One nice touch that was not present on previous PEN bodies is a dedicated movie button, allowing the user to start recording at any time. The shutter release also has a great feel, allowing the user to feel half press even with dive gloves. Camera installation and removal is a breeze. There's no camera tray like SLR housings and the camera just easily drops into place on rubber guides. The latch system has a lock to prevent accidental opening. Many new shooters have commented that they like the clear back door as it allows them to see the o-ring and verify any leaks at the beginning of the dive. Our critiques on the PT-EP01 underwater housing It's important to remember to pop up the cameras flash prior to putting the camera in the housing. There is no way to pop the flash up underwater. Since the pop-up flash is required to trigger your underwater strobes, forgetting this step can be a deal killer on an important dive. The zoom gears are of a flexible but firm material that is easy to install on the lens. However, the zoom knob on the housing is just stiff enough and positioned is such a way that one finger operation isn't possible. While we didn't find this problem a huge issue in our tests, cold water divers and frequent zoomers should take note. Automatic flash results with the E-PL1 are excellent even in tricky situations with a bright foreground and a dark background. Unlike most compact cameras, the PEN allows you to shoot the camera in manual exposure mode while the strobes are set to TTL. With this technique, the strobes are automatic, but you can control the background with shutterspeed.Optional Zen WA-100 dome port for a wider view While the flat port that comes with the Olympus housing is great for photographing macro subjects, photographers who want go wide need a better option. Fortunately, Zen Underwater rose to the challenge and developed an affordable dome port for the Olympus PEN Housing. The Zen WA-100 dome port is designed to match the Olympus 9-18mm lens, creating a combination that gives substantial versatility allowing the photographer to shoot anything from fish portraits to wide-angle scenes. Shooting the 9-18mm lens through this port instead of the stock flat port affords a 33 percent increase in angle of coverage over the flat port, getting it back to the full 100 degree field of view that it has on land. The Zen WA-100 is user-installable, and it's a simple matter to switch between ports in the field. Zen Underwater has also announced the development of dome ports to match the Panasonic 7-14mm and 8mm fisheye lenses, so the E-PL1 truly has a wide variety of options when it comes to optics. The optional Zen WA-100 dome port adds 33% wider coverage underwater with the Olympus 9-18mm wide angle lens over the stock port. We were impressed by this dome port's flexibility and sharpness from 100 degree wide to full zoom close-ups.This photograph was taken with the Zen WA-100 dome port and Olympus 9-18mm lens at a distance of only 6 inches. The 100 degree coverage of this setup allows you to get very close to your subject, but still maintain a wide field of view.Should I consider moving up from a compact camera to a PEN system? The PEN represents the next step up from a top level compact camera such as the Canon G12. With the PEN, you get a larger imaging sensor, better image quality, and faster shooting. However, even though the PEN is smaller than traditional DSLR cameras, it is still larger than the Canon G12 and can't slip into a shirt pocket like a Canon S95. The menu system on the Olympus E-PL1 is more complex, and it is more expensive to outfit the Pen with a wide angle lens and a dedicated macro option than it is to configure a similar package for the Canon G12 or Canon S95. If you currently shoot a compact camera and would like to upgrade performance, but you find a full DSLR is out of your price range, the Olympus Pen is a compelling alternative. Should I consider moving up to a traditional DSLR over a PEN? When compared to a traditional DSLR, the PEN is significantly lower priced than entry level DSLR's like the Canon T2i or NikonD7000. The PEN's smaller camera body, smaller lenses, and smaller housing result in a system that can easily be taken as carry on luggage. However, when you compare the PEN to entry level DSLRs like a Canon T2i or NikonD7000 its slower shooting speed, smaller sensor size, limited selection of lenses, and lack of full 1080p high definition video should encourage the serious photo enthusiast to consider a full size DSLR if the budget allows. Camera Feature Comparison ChartCanon S95Canon G12Olympus E-PL1Canon T2iShutter delayYesYesNoNoManual FocusYesYesNoYes*Focus LockNoNoYesYesFocus SpeedGoodGoodBetterBestShooting SpeedGoodGoodBetterBestTTL strobe in Manual Exposure ModeNoNoYesYesImage QualityGoodGoodBetterBestMax Video Resolution720p720p720p1080pSizeSmallSmallMediumLargeCamera and Housing Cost From $598 From $698 $1098 From $2128 *With non-zoom lenses. Conclusions Olympus has scored a hit with its smallest and most affordable micro 4/3 body yet, and we're very impressed with the small size and quality of the Olympus PT-EP01 housing. This system bridges the gap between compact and DSLR. The PEN's larger sensor produces lower image noise than all other compact cameras, has no shutter delay, is more future-proof with its interchangeable lenses and priced and sized well below traditional DSLR options. The custom ports from Zen Underwater offer additional flexibility with this system, allowing underwater photographers to maximize their investments in high quality interchangeable optics. If you're looking for a lower cost pocket sized camera, we'd recommend you consider the Canon S95 and Canon G12. If underwater photography is becoming a serious hobby, we'd recommend you consider the higher performance DSLR such as the Canon T2i and NikonD7000. However, if you find yourself in the middle on size and price, the Olympus E-PL1 and Olympus PT-EP01 housing might be the perfect package for you.