What seems to be the main points of discussion around the legacy Vivitar MC 28mm f/2.8, a classic manual focus wide-angle prime lens acknowledged as an excellent example of a third-party lens manufactured in the 1980s, are not about the quality of their images, but rather the origins of its manufacturer.
The lens, known to have several variants, is primarily manufactured by Komine, is identified by the serial number 28xxxxxxxx. And is available in multiple mounts, including Canon FD, Minolta, Nikon, Olympus OM, Pentax K, and others.
The unit I have, however, has the serial number etched on the lower part of the lens barrel itself (rather than on the lens trim plate), and has the serial number starting with 98xxxxxxxx, which, as pointed out on PentaxForums, is manufactured by Cosina.
Nominally, as described for the Komine version, the lens is a 7-element in 7 groups design with multicoated elements, has 6 iris blades, a minimum focusing distance of 0.3 meters, takes 49mm filters, weighs around 206 grams, and comes with a non-rotating front element.
The Cosina version of the lens enjoys a rating of Sharpness at 7.7, Aberrations at 7.7, Bokeh at 7.4, Handling at 8.0, and Value at 9.1 on the forum.
Aside from the starting serial numbers already noted, there is also a version identified as Vivitar 28mm f/2.8 Close Focus Wide Angle, which differs from the 28mm f/2.0 version by having a slower aperture and an aperture click between f/11 and f/16, and a Kiron version of the lens with serial numbers starting with 22xxxxxxxx.
On the mirrorless Olympus PEN E-PM2, the lens is equivalent to a 56mm lens on a 35mm full-frame camera, with a versatile mid-telephoto perspective that is an excellent choice for portraits (headshots to half-body), with potentially excellent subject isolation and creamy bokeh.
The focal length is also excellent for detail shots in travel, and isolating subjects in street photography with compression that adds a pleasing, three-dimensional look.
On APS-C DSLRS with 1.5x crop sensors, the Vivitar MC 28mm f/2.8 will be equivalent to a 42mm prime, just a titch wider than the 40mm, which is considered the 'sweet spot' lens for photography for its natural perspective that mimics what the eye sees, ideal for everyday shooting, street, and travel, for its ability to balance wide scenes with subject isolation.
The Olympus PEN E-PM2, one of the smallest and lightest footprints among interchangeable lens cameras, is an entry-level MFT (Micro Four Thirds) system camera introduced in 2012. The camera features a 16.1MP CMOS sensor, the same as found on the OM-D E-M5, acknowledged for its excellent image quality and color reproduction, a 3-inch touch LCD screen, Full HD 1080p video recording with full-time autofocus.
