Replicating "aperture request" mode with Olympus

Ellsass wrote:

I just got an E-PM2 and have been using a GF5 for about a year. I'm trying to figure how to copy a behavior I became accustomed to on the Panasonic.

I shoot in P mode, though I mostly fiddle with the aperture, often keeping it as wide open as possible without overexposing. On my GF5 I could simply spin the dial on the back of the camera to widen the aperture. See the meter at the bottom of the screen here:

That red area is where the camera would consider the photo to be overexposed — the lens maxes out at f1.7 and apparently this shot would be blown out anywhere above ~f2.5. As I spun the dial, the aperture would "stop" once it hit the red zone. (If I wanted, I could momentarily let go of the dial and spin it again to force an overexposed picture.)

But as far as I can tell, my EPM2 offers no such "danger zone" hint. In A mode it will gladly open the aperture all the way and provide me with a nice white photo souvenir (the overexposure is annoying not shown in the live preview, only in the recorded image). In P mode I can't seem to directly change the aperture.

Any ideas?

This is the program shift feature (called that by both Olympus and Panasonic).  As you mention severe overexposure resulting, I wonder whether, on the E-PM2, you are actually accidentally engaging exposure compensation rather than program shift?  Generally, once you get to the end of the available range for adjustment with Program Shift, it just stops, rather than letting you impose incorrect exposure.  The dial is so configurable on the Olympuses that some owners will have a plain spin of it set to carry out program shift (as I have my Olympuses set) whilst on others this will instead give exposure compensation, and if memory serves, out of the box (once you have unlocked the dial), the default for just spinning the dial in P mode is indeed exposure compensation.  You generally switch between the two functions of the dial by pressing the "up" direction, as marked by the +/- square symbol, to access the secondary function, so in the out-of-the-box configuration, you'd need to press "up" before getting Program Shift as the dial action.  One of the first things I do is to swap this over in setup so that moving the dial engages program shift, and a press "up" is needed to switch it to exposure compensation, since Program Shift is far less destructive if engaged accidentally.

Regarding forewarning of over and underexposure, Olympuses do have a useful display mode that you can engage where you get live "blinkies" - red and blue flashing areas signifying over and under exposure, similar to what many cameras will show in playback only (which you can also have, of course).