The E-P1 ships in a kit with one of two kit lenses; a 14-42mm zoom and a 17mm f2.8 pancake. the lenses' full designations are:
M. ZUIKO DIGITAL ED 14-42mm 1:3.5-5.6 (black or silver) - 28-84mm equivalent
M. ZUIKO DIGITAL 17mm 1:2.8 Pancake (silver) - 34mm fixed wide equivalent
As mentioned earlier Olympus is also launching two new adapters for the E-P1, allowing the use of standard Four Thirds lenses (with full functionality including autofocus) and OM mount manual focus lenses (obviously you'll only get manual focus but you do get metering)
E-P1 with its two kit lens options: 14-42mm and 17mm pancake. Note the 'PEN' branding on the lens boxes.
With the 17mm F2.8 pancake lens attached the E-P1 really is very small (approaching pocketable if you're wearing an overcoat), but the zoom is, inevitably, a bit bulkier, although it does have a nifty trick up its sleeve; a collapsible barrel that almost halves it in size when it's not in use.
Although it looks a little front heavy when extended, the E-P1 and 14-42mm combination is incredibly compact when collapsed, and the lens is very light and feels well balanced in use.
When collapsed the M. Zuiko zoom is tiny - just over 41mm deep with diameter of about 59mm at its widest point. Press the unlock button and give the barrel about 1/8 of a turn, and the rest of the lens pops out from inside, almost doubling the length of the lens to 75mm (at the 14mm setting).
The 14-42mm M.Zuiko has a small locking button on the zoom barrel. This allows you to turn the barrel way beyond the 14mm point, collapsing the lens to just over half its length.
It's a neat solution to the problem of how to make a zoom lens small enough to match the EP-1's diminutive body.
Even when extended the zoom is nicely balanced on the E-P1's body. The 28-84mm equivalent zoom range makes it the perfect all purpose kit lens, though (perhaps inevitably given the size) it's a little slow at the long end (F5.6).
The 17mm only adds around 20mm to the depth of an already slim camera, making the perfect walkaround street or landscape camera that is - if not pocketable - certainly highly portable.
Micro Four Thirds (MFT) is an extension of the Four Thirds standard that Olympus, Leica and Panasonic have used for their recent DSLRs. At the moment the choice of MFT lenses is sparse (but growing); a couple of kit zooms and the lovely new 7-14mm from Panasonic (with a 20mm F1.7 pancake coming soon) and the two lenses announced with the E-P1, but the system is backwardly compatible with standard Four Thirds, and you can (via an optional adapter) make use of the extensive range of 4/3 lenses from Olympus, Panasonic, Sigma and others.
The ultra short flange back and small lens mount actually makes Micro Four Thirds, theoretically, the most 'lens compatible' system on the market - you could in principle produce physical adapters for just about any lens designed for 35mm (or larger), specifically manual focus lenses from older film SLRs. Olympus has already launched an adapter for its own legacy OM (manual focus SLR) lenses, Panasonic is promising one for Leica M and R lenses, and third parties are looking at a range of other options. It's not surprising camera geeks are excited by the possibilities offered by the new format.
Although at the moment there's not many dedicated Micro FT lenses on the market (above right you can see the new Panasonic 7-14mm mounted on the E-P1), you do have the option to mount standard Four Thirds lenses, and they should all autofocus (albeit slowly).
The MMF-1 adapter allows existing Four Thirds lenses to be used with the Micro Four Thirds mount. The adapter is not designed to work with other accessories, such as tele-converters and extension tubes.
Using the adaptor, the E-P1 can mount the full range of legacy Four Thirds lenses. However, the camera's small size means some lenses - such as the 25mm pancake here - are better balanced than others.
Olympus is being a lot more accommodating to those wanting to use nonstandard lenses on the E-P1 than it ever was with standard Four Thirds, and is launching an OM adapter at the same time as the camera. The MF-2 lets you mount all your old Zuiko lenses