Thank You Godfrey and Brian
I'm not exactly sure what causes aperture chatter. It seems to occur with Panasonic glass mounted on Olympus bodies and in shooting modes which allow the camera to control the aperture (e.g. program or shutter priority). If that is true, would not shooting in aperture priority prevent it from chattering?
I have been considering an EM-1 to replace my ancient G1 and it's kind of disheartening to hear some Panasonic optics aperture chatter (25mm, 45mm macro) and some color fringe with bright light sources in the frame (7-14mm and 20mm).
http://forum.getdpi.com/forum/images/smilies/frown.gif
Since all my glass is Panasonic, perhaps I would be better off staying with a Panasonic body.
Paul
Regards the aperture chatter. I'm certain either. It was clearly an annoyance with the E-PL1 body I first tested the Summilux 25 on—I'm not certain whether it's worthy of being called a "problem" as I don't know that it has any effect other than to make some annoying noise. My cameras are almost always exclusively in Aperture priority mode, with some minor trips to Manual exposure mode BTW.
All these cameras do make coordinated, dynamic adjustments to the aperture opening to maintain the viewfinder brightness when viewing and focusing. That's why both Panasonic and Olympus provide an explicit "preview" function which will hold the set aperture for scene evaluation. The difference between the TTL electronic and SLR world in this respect is that the latter worked more simply: auto diaphragm operation just held the lens wide open for focusing, so any noisy aperture jittering around wasn't an issue.
I had the G1 too, it was a great piece for being the first Micro-FourThirds offering and returned a heck of a lot of excellent photos for me. The E-M1 is a far more mature and up-market replacement for it, IMO. Never used the 7-14mm. The Panasonic 20mm I had and was never quite pleased with, the M-E 45 was a delight on the G1 and proves the same delight on the E-M1 if not more so (the brief moment of aperture chatter notwithstanding), and the Summilux 25 is as much of a delight as the Summilux-D 25/1.4 ASPH for FT SLRs was (it had rather noisy aperture operation too, although you didn't hear it very much due to being used on the SLRs most of the time).
The color fringing with the Panny 7-14 is the most serious negative you list, and why that occurs I haven't the foggiest notion. I'm happy I have no urge for such a wide lens ... the ZD 11-22 and the Panny 14 with Sony wide converter do wide very nicely for me.
So ... well, you have to decide for yourself what you're willing to risk. I rarely let the online reviewers and commentary sway me much one way or another: I buy what I think will work, test it, and figure out where the warts are, avoid them, where the goodness is, exploit it, and then figure out whether I want to keep the stuff.
With the lenses I've got now, I haven't found too much in way of warts to bother me with the E-M1. I'm pretty happy with it.
G