[dave9t5]

[quote name='edge' timestamp='1312645653' post='10430']

What is the exact impact of post-distortion correction?

You lose a bit of angle of view and softer corners?

[/quote]





[quote name='Klaus' timestamp='1312645919' post='10431']

Yes

[/quote]



The article claims that they checked the field of view:



"It’s also worth mentioning here the field of view issue. We measured it for JPEG files using the method of panoramic sequence and the sky photo method - taking angular distance measurements between stars of the celestial sphere. Both methods produced the same result of 73.7 degrees on the longer side (with the margin of error not exceeding 0.2 of a degree) so exactly as much as we expect from a 12 mm lens on a 4/3 sensor. You should remember that the field of view in RAW files will be by several degrees wider. "



So seems the true focal length is "several" degrees wider. I don't know if it's always the case for m4/3 manufacturers to accurately label their lenses' corrected focal lengths or the true focal length. It must be tempting to label the true focal length (which cheats the user), so kudos to Olympus for being a bit more truthful about the effective focal length. Or is there a standard for m4/3 focal length labeling?