This is an unusual lens. Not only is it a macro lens capable of photographing subjects as small as 2x the sensor size (hence the 1:2 designation), but it is also a fast short tele suitable for portraits, with a maximum aperture of f/2. The focal length is 50mm, however, with the 2x crop factor associated with Four Thirds, it will have the same field of view as a 100mm lens on a traditional 35mm camera.Since this is a Four Thirds standard lens, it cannot be used on a Micro Four Thirds camera without an adapter. It is shown here with the Panasonic DMW-MA1 adapter attached. The Olympus MMF1/MMF2 adapter would have done the same job, as it is functionally the same, albeit usually somewhat more expensive at retail.
Focus
Unfortunately, you cannot use autofocus with this lens together with the first series of Panasonic Micro Four Thirds camera bodies (G1, GH1, GF1). The Olympus cameras, and newer Panasonic cameras, on the other hand, can do autofocus with this lens, albeit operating at a slow speed. Here is a demonstration of the autofocus using Panasonic GH2, which takes five seconds to focus down to 45 cm distance:
Here is a demonstration of manual focusing with this lens on a Panasonic Lumix GH1.
Some Four Thirds lenses can autofocus on Panasonic Micro Four Thirds bodies.
The closest focus distance is 0.23 m. Be aware, though, that the focus distance is measured from the focal plane (the sensor), and so the distance between the front lens and the subject at closest focus is about 0.1 m.
The lens is also special in that it is one of the few Four Thirds lenses that feature a focus scale.
Size
Compared with the Lumix G 20mm pancake lens, the Olympus 50mm macro, including adapter and hood, is enormous. However, it is of course more natural to compare it with other 100mm equivalent macro lenses, in which case it is remarkably compact.
It is somewhat smaller than the Lumix G HD 14-140mm kit lens.
Macro lens
Most macro lenses have a maximum aperture of f/2.8 or slower, e.g., Sigma 105mm f/2.8 and Tamron 90mm f/2.8, both in the same focal length range. Hence, a f/2 macro lens is unusual, and some might say this speed is not needed. You would rarely photograph small subjects with such a large aperture, since the depth of field (DOF) becomes very narrow. Unless the subject is more or less flat, only a small part of it will be in focus at f/2. Stopping down to at least f/5.6 may be needed to have a sensible depth of field at close focus.
Here is a series of photos that illustrate the depth of field at 25cm distance, and various aperture sizes. The focus is set to the centre face. The distance in the axis of the lens between the three heads is one LEGO unit, or 8mm, if your not familiar with this measure. You must stop down to f/16 to get a depth of field that covers this distance.
At such a small aperture as f/16, you are going to see some lack of sharpness at the pixel level due to diffraction. You may still choose a small aperture like this, however, if you need a wide depth of field, and can live with some dullness at pixel level. For web use, for example, where you will normally scale down the image, this should not be any problem.
In macro photography, it is uncommon to use autofocus, since you will need to fine tune the focus anyway to get the desired effect. So the lack of autofocus on Panasonic Micro Four Thirds cameras is not a problem for macro photography.
Bokeh
I've made a study of the bokeh of the lens. My conclusion is that the bokeh is very pleasing, although the out of focus highlights have a somewhat hard edge. But in general, you're unlikely to be dissatisfied with the bokeh using this lens.
Portrait lens
When taking headshots, it is common to keep some distance to the subject. This is done to avoid perspective distortion. Taking a picture of someones face from a short distance will usually give unwanted distortions, e.g., showing an unnaturally large nose or a large chin. Traditionally, an 85mm lens has been used on a 35mm camera to be able to fill the head and shoulders of a person in a picture frame, and still keep enough distance to the person to avoid perspective distortion. The Olympus 50mm macro lens corresponds to 100mm focal length on a 35mm camera, and so it is useful for portraits.
A traditional portrait lens will be around 85mm f/1.4. The Olympus 50mm macro has one stop slower aperture at f/2, but it is still large enough to isolate the background when taking portraits.
In studio photography, the lack of autofocus is not likely to be a problem. If you're photographing people in a more dynamic environment, you may see the need for autofocus.
Other uses
You could also use this lens for concert photography, given that you're placed not too close to the stage, and the people on the stage are not moving around too much. If you've got something to rest the lens against, you may be able to use longer shutter speeds.
Sharpness
This lens is generally considered to be among the best in the Olympus Four Thirds lineup. It is remarkably sharp from f/2, but close it down a bit for even better sharpness. At f/5.6 it is probably around the sharpest.
Chromatic aberrations
I have made a study of the chromatic aberration (CA) artifacts of this lens, and some other prime lenses. It shows that there are quite some red/green fringing artifacts even in the centre of the image. You will note this if you photograph high contrast images.
Image stabilization
Using this lens with a Panasonic Micro Four Thirds camera, there is no image stabilization available at all. You'll normally want to use a fairly short shutter speed, e.g., 1/60 second or faster, to avoid camera shake affecting the image when handholding the camera.
Olympus Micro Four Thirds cameras have image stabilization built into the bodies, which will work with this lens.
It is perfectly possible to use this lens when recording videos. However, you can only focus manually on Panasonic cameras. With the lack of image stabilization, and a pretty long focal length, it is more or less impossible to handhold the camera stably while recording movies. Using the electronic viewfinder and pressing the camera against your face may help you to stabilize it a bit. But using a tripod is preferred when filming with this lens.
Hood
The lens comes with a bayonet hood, to protect against stray light. I found the hood to be a tad bit long, making it difficult to fit the camera with lens and hood inside my small camera bag, so I chose to use a 52mm screw-in hood from B+W. The hood also protects the front lens element from objects touching it accidentally.
Example picture
Here is an example picture of a broken Leatherman tool taken at maximum magnification (closest focus distance), f/10, 1/5 s, ISO 100.
Other macro options
It is also possible to achieve macro close up photos by using macro extension rings.
Another, more expensive, option is to use the Panasonic Leica Lumix 45mm f/2.8 1:1 Macro lens, which is a native Micro Four Thirds lens.
