http://www.dpreview.com/lensreviews/panasonic_20_1p7_o20/

Here it is! I just put in an order for one here in Japan.

One question (basic photography question): the 17mm Olympus pancake stops down to f22, where the Panasonic 20mm only goes to f16. What sort of difference will this make in usage and sharpness ?

I just read the review and the lens achieves all my expectations, I can´t wait to have it and try by myself.

the lens barrel  diameter size should have been , and could have ,been similar to the panny 14 -45 or smaller imo ,also this huge hockey puck of a lens [but  sufficently flat i concede] , which dismayingly, [for panny owners ] does NOT have OIS , looks pretty good  for olympus owners in the image quality dept , which is what really counts for me

im beginning to trust the objectivity of dp reviews less and less in the  past year, in the cons of this lens review conclusion it only lists price ,land not the lack of ois in a lens designed by a manufacterer that does not offer in body stabilization in any of its m4\3 cameras. this in a 400 dollar lens?? also i cannot understand why this lens is not  1.4 or even 1.2...

ive said it before and ill say it again here , the lens looks to me like a hockey puck with a coin sized optical element in the middle.. even at these very wide f stops  0f f 1 .4 or faster, the glass and mechanics would not have exceeded the size  that  is used in , say the "normal' 1.8 full frame nikon that  sells for about $110 dollars, and is a fine, well made lens designed for an image circle 4 times the size that  employed in m4\3

lack of ois is most definately a  BIG con for most of the intended users [gf-1, other g series users] of this otherwise fine lens, dp reviews decision not to mention a stronger objection to this defecit is curious to me , it should have been mentioned in cons  

Remember that pancake designs are quite different from standard optics, and require smaller elements...going to a 20 f/1.4 or f/1.2 would probably have not been possible keeping it in the pancake optical design...it would have necessitated a change to a standard optical design, which would likely have doubled the length.

And, um, the Pen DOES correct the distortions on the 20/1.7.  Distortion correction is contained in the lens firmware, not in the bodies.  DPReview confirms this.

I was just wondering the same thing. I know I've seen e-p1 users raving about that lens. Are they not noticing the flaws, or is the camera actually correcting them. I was fairly certain that all the micro four thirds lenses were supposed to work on any body AND communicate with the camera. If anyone can confirm or deny it, that would be very helpful.

On a related note, I am smitten with the e-p1 but after reading up on all the lenses I feel like getting the Lumix lenses instead, so it would be very important to find if they work as they are designed. Has anyone tried them and compared? I don't plan on getting a bunch of lenses, just a few, so I'd like to get the best ones I can (without breaking the bank).

Popo is correct...  Federico, you said distortions...it does correct distortions, it doesn't correct CA.  The Oly bodies don't correct CA on Oly lenses either (easy to fix in Lightroom anyway). 

I guess if you really want an auto-focus lens that sort of works in low light, it's a good deal.  Otherwise, if you have a low light lens, just get an adapter if you haven't already.   I don't know what the advantage is in having a pancake lens other than it makes the camera look like a G10.  Hopefully, Olympus will release a faster 17mm in October within the same price range.

i do feel that is is necessary to have ois on a 20 mm lens..... remember the vibrations will be approx doubled as if a 40 mm lens was employed
the ois in camera of the ep-1 offers a manually settable 8 mm if im not mistaken , it must be usable at wider focal lengths if it offered by the camera designers, no?

a 40 mm normal- wide equiv prime will certainly benefit from ois in my opinion, even one stop is a wonderful benefit  , but g series owners will get no benefit unfortunately
a 20 on a full frame however is alot more forgiving and could probably get away without it

i would love to own the 7 -14  lens i hope tamron offers a similar lens for 5 or 600 soon so i can afford it

I guess some people here don't shoot low light. I have found myself using a f/1.4 lens, with sensor shift stabilisation, at high ISO, and still needing more without reaching for a flash or tripod.

f/1.7 is a good start, particularly for a pancake. I still hope for longer/brighter pancakes in future.

You're right on the price....but they know GF1 and E-P1 owners are going to be all over a decent fast pancake so it's priced accordingly.

I'll still be getting one :S