How do you manually focus with E-PL1?

Just press magnification button (it's right under your thumb) and E-PL1 will show you magnified view.

However, when I used E-P1, I found manual focusing on the LCD to be unreliable. Of course, E-P1 can't use Olympus excellent EVF, so I ended up buying LCDVF (a cheap knock-off, not the real thing) and using it for manual focus. With E-PL1 I strongly recommend getting Olympus VF-2 - it's much better than Panny's DMW-LVF1 for GF1. If I had GF1, I would probably use LCDVF for manual focus instead of EVF.

 

No, this control wheel is for changing shooting parameters. You must focus with your lens' focus ring.

 

Also you have to options, you can us af with manual access. That way you let the camera get close with the AF and fine tune the critical focus with MF. But it does well if you use the lcd when you zoom it. But the VF2 is much better for MF applications.

 

The OP asked with reference to the 20mm lens, but it may be worth noting that with MF on legacy lenses, a push of the GF1 control wheel magnifies the view.

This is very useful, and especially so when using the EVF as you can easily find the control with the camera to your eye.

While the EVF for the EP2 has much higher resolution the that for the GF1, this does not (for my purposes) mean the latter is bad. I find it very effective, and considerably more compact too.