First of all I want to state that I do not take any scientific tests on sharpness or ISO comparisons with other cameras. I just evaluate the pure shooting experience by going out taking photos.
This one is my second oldest lens for Micro Four-Thirds. I bought my G2 together with the kit lens, the 14-42mm, and the 45-200mm. Soon I felt limited with those two lenses and wanted something faster to shoot under low-light conditions and have a little more control over the depth of field and separation of the subject from the background when shooting portraits. Two years ago the lens selection for mFT was not as big as it is today but the 20mm was exactly what I was looking for: Small, lightweight, fast, reasonably priced and able to deliver amazing results.
Soon this lens became my most favorite lens for my G2. Nonetheless I had to get used to using a fixed aperture lens like the 20mm prime. You have to move more frequently to get the shot you want and have to think more carefully about the shot you want to take and what should be in the frame. Where you can crop out disctracting elements by zooming on a zoom lens you have to move and reframe more often with a prime. But after a little while I liked this way of shooting and today I am almost using primes exclusively.
When I first looked at some sample images I took with my new lens on the G2 I was amazed. The images retained much more detail than my kit lenses and the artistic possibilities due to the maximum aperture of f1.7 were incredible. But now on the OM-D this lens really shines. The sharpness it offers coupled with the new 16 Megapixel sensor in the EM-5 is amazing. In addition the images are contrasty and offer great colour.
Now two years later I still use this lens regularly on my EM-5. Even with all the competition caused by all the great Olympus primes like the 45mm, the 75mm and even the 60mm macro lens. Indoors this lens is unbeatable as a portrait lens. But you have to leave enough space between you and your subject to prevent distortion this lens might cause due to its wide focal length. Another thing some users have reported is the so-called banding issue with this lens and the EM-5. This issue appears when you shoot this lens with ISO sensitivities of 3200 and higher and presents itself with horizontal stripes in some areas of the frame. I noticed it once when I was shooting at night and used higher ISOs. But following a tip on the internet to warm up the sensor by taking four to five shots at the beginning of the shoot I got rid of the issue.
The only downside of this lens in my opinion is the slow autofocus. Especially in low-light situations you can see the autofocus hunt and take time to lock on. This is less of an issue for me since I normally shoot static subjects with this lens and when I do shoot portraits with it the conditions are usually well lit but it may be a concern for some.
- - very sharp from corner to corner even wide open
- - fast with max. aperture of 1.8
- - small and lightweight
- - reasonably priced
- - great build quality
- - slow autofocus
- - possible banding issues on EM-5 with high ISOs