Olympus Zuiko ED 7-14mm f/4

Firstly I'm surprised it's taken WDC so long to review this lens ... (I bought mine, early 2006! It's certainly bulky & heavy, but suspect this is due to being of Retrofocus and Telecentric design. Whilst there is a very small amount of barrel distortion, one of the major features of this optic in comparison to others, (Prime & Zoom-wise) the 1-1.5 f-stops in exposure variation between the centre and edge (C to E)of images, is quite outstanding. Maybe this lens applies some in-lens processing to correct this, as this is quite common 'trait' with ultra-wide lenses. For instance, the 12mm f5.6 Helier, has a 3 f-stop C to E variation and some users buy a Heliogon circular grad filter to correct this, reducing it's maximum apeture down to f11 ... The lens hood is non-detachable and extends beyond the front element, offering some protection when placed face down on a smooth surface. The lens cap is very deep, covering the depth of the hood. This hood could be improved by employing some form of 'bayonet lock' on the cover and lens to offer additional security to the front element ... The cap hasn't as yet ever shown signs of becoming a looser fit, but it isn't a really tight fit. Focussing is 'fly by wire' rather than mechanical, which initially feels a bit 'odd' but you soon adapt to it. The large barrel diameter means that one usually cradles the lens in the palm of the hand, reducing any chance of camera shake. The build quality is superb, and although it is impossible to fit filters over the front lens, looking at the shrouding provided on the rear element, it may well be that a MkII version, might introduce the fitting of filters on this end instead, (as per some mirror lenses) but I highly doubt that a Polariser will be one of these! It's certainly expensive, but the the extreme angle of view (max 114 degrees horizontal) and very fast f4 (fixed) apeture more than make up for this.