If you like wide angle lenses you will love the 20mm Prakticar/Flektogon.
The 20mm Flektogon has the same advantages as its’ little sister the Carl Zeiss Prakticar/Flektogon 35mm (close focusing, sharpness and a good bokeh). It offers a much wider angle of view with 93° compared to the 62° of a 35mm lens (on full frame cameras). What really sets the 20mm Flektogon apart from other super wide angle lenses is not only the close focusing distance but also that it is a relatively sharp lens at f2.8. This makes it suitable for available light photography in most cases. Obviously all this goodness comes at a price premium with the 20mm Prakticar being about twice as expensive as the Carl Zeiss Practical 35mm.
The Practical Flektogon does not only offer outstanding image quality but this lens is also remarkable due to its’ extremely short focusing range of only 19cm, which is pretty amazing for such a wide angle lens. This enables you to get really close to your subjects creating almost fish-eye looking images and distorting effects. Obviously this rules out “natural looking” portraiture images if the subject is too close.
When you focus to infinity, the distortion is really minimal and you do get authentic looking pictures. The lens offers a massive field of view which is especially handy for landscape and architecture photography.
The colours and sharpness are really good, although in my opinion not as good as the Carl Zeiss Prakticar/Flektogon 35mm. Especially in the corners you do get some softness when shot wide open.
If you have the opportunity to acquire one of these jewels go for it – you won’t regret it!
Type: ultra wide-angle
Name: Carl Zeiss Jena Prakticar 2.8/20mm
Coating: Multi-coated glass
Focal lenght: 20mm
Mount: Praktica PB + Canon EF adapter
Maximum aperture: f/2.8
Minimum aperture: f/22
Quantity of ap. blades: 6
Lens scheme: 9 elements in 8 groups
Closest focusing distance: 0.19m
Serial number: 7358
Filter/attachment size: 67mm