Following on Part 1, I will present some sample images of the Olympus G. Zuiko 40mm f/1.4 and discuss its usability.
First, to consider the focal length. This lens is DOF/FOV equivalent to an 80mm f/2.8 on full-frame, which is a capable telephoto configuration. The equivalence for APS-C is 51mm f/1.8, which means that it corresponds to a typical fast fifty on the Pentax system I know and love. This is a field of view I enjoy, since I prefer something either tighter than the "normal" field of view (which is 21mm on the Micro Four Thirds format). That's why you'll find me shooting 43mm or even 77mm as a general "walk around" lens on APS-C.
The Zuiko is a pleasure to hold and use in the hand. The focus ring is smooth and tight, so it's easy to lock in focus at the correct point. The design of the E-P1 helps here, since one gets a definite "shimmer" effect on the LCD when focus is achieved. With practice one can depend on this and on use the focus magnification only in extreme cases (narrow DOF at close distances).
The design does have one peculiarity. As you can see from the picture above, the aperture dial is in front of the focus ring. Furthermore it is marked in f-stops on the underside, where you cannot see them. But the visible top-side portion of the ring instead notates the aperture in arbitrary numbers from 0 to 6. I am not sure what the rationale was behind this!
The "0" setting corresponds to wide open, that is, f/1.4. The "1" stop corresponds to f/2.8, which unfortunately means that there is no setting for f/2. It is possible to set the aperture between these two detent clicks, as I did for the tests in the previous article, but I find this annoying. Whole stop clicks continue up to the minimum aperture of f/16 or "6" as this dial would have it.
The lens takes a 43mm filter; since I am still waiting for a hood in that size, I took care to avoid perspectives that might induce flare. Since the glass is near the front of the lens I would definitely mandate a hood both for protection and image quality.
The shot above is deliberately out of focus, and wide open, to show some distinct bokeh effect. The five blades are curved in order to form a smoother perimeter, but they do not form a perfectly symmetrical pattern. I should point out that this is true even on my Pentax FA 43mm Limited.
I shot the mauve flowers at the top of the article at f/2.8, if I remember correctly. My usual portrait sitter Schweppes, below, is pictured at or near wide open. All of these images have been processed using my usual work-flow, in order to get a good result out of the RAW files.
In conclusion, I have to say I enjoy the slim profile of this lens and the field of view it gives me to work with. Focus and handling are a joy. I especially like the ability to get close to my subject. The lens is suitably sharp and renders a neutral image, without "swirly bokeh" effects or mystical aberration glow. Use from wide open is perfectly acceptable, with a peak in sharpness at f/4. For kicks I shot a brick wall and found no overt distortion. (Since I enjoy street art, I do in fact find myself shooting walls.)
On the down-side, the lack of proper f-stop marks and the omission of a detent at f/2 is annoying. The need to compensate the exposure when stopping down is a puzzle. It won't annoy me excessively as I imagine I'll be using this lens mostly at f/2.8 or f/4.
When introduced in the sixties this lens sold for $70. Though it is likely the most abundant PEN lens on the secondary market, copies sell for between $200 and $325, depending on condition and how lucky you get.