Question about aperture of Lumix 20/1.7 on Oly E-P2

[awilder]

I noticed the Lumix 20/1.7 opens to f/2.8 for normal viewing on my E-P2 but will fortunately open to the correct aperture selected when the shutter is released. I assume this is normal since the fastest u4/3 lens Oly make is f/2.8. Is this correct? I was also surprised at how noisy the lens was when autofocused. It's like a high pitched squeal. I assume this is normal too given mention in the instructions about noise when autofocused. Interestingly, the new Oly 9-18 is completely silent when focusing.

 

[efix]

It is my observation that in preview mode, the PENs stop down the lenses according to light levels, so that not too few and not too much light hits the sensor.

And yes, the 20 is quite noisy

 

[deirdre]

My 20mm isn't particularly noisy (though likely too noisy for video), but I'm using it on a GF-1. It seems weird that it'll only open to f/2.8 for normal viewing. In four-thirds, Olympus makes several f/2 lenses, and I'd expect them to behave like f/2 lenses on the E-P2.

Edit: well, someone else explained it above.

 

[igi]

It is my observation that in preview mode, the PENs stop down the lenses according to light levels, so that not too few and not too much light hits the sensor.

And yes, the 20 is quite noisy

Yup, I think this is correct. I have also noticed this even on my E-P1.

 

[PeterB666]

I have both of these lenses and yes, the 20mm is a noisy little thing. The aperture noise is the oddest thing out.

The 9-18mm lens is a little gem.

Hmm, imagine if they could breed. Something in-between like a 9-18mm f/2.8 constant aperture zoom would be nice.

Edit: - I have an E-P1

 

[deirdre]

Maybe I'm just comparing the 20mm to the camera that came before. Compared to the old Canon P&S I had, the 20mm is quiet.

 

[M4streetshooter]

The 20's not too bad but there are copies of the 17 that really sound like a truck....
It's strange that I had 3 copies at one time and 1 was very quiet the other 2 were very noisy.