Comparison Carl Zeiss Flektogon 20mm f2,8 and Carl Zeiss Flektogon 20mm f4


Today I took some test shots to compare the Zeiss Flektogon 20mm f2.8 and the Zeiss Flektogon 20mm f4.

Both of these old vintage lenses have the m42 mount and can be adapted to every modern camera (Sony, Canon, Nikon, Pentax, Fuji etc.). The M42 mount is the best to adapt.

The design of both lenses is almost indestructible. They are completely made from metal and glas.

When it comes to the price, the f4 version (160€ at is about 100€ cheaper than the f2.8 version.

Optical Quality

When you compare the optical quality of the lenses, you soon realise that the Carl Zeiss Flektogon f2.8 is the better lens.

click the image to enlarge it

The Flektogon f2.8 is sharper even wide open at f2,8 compared to the f4 version at f4.

This better sharpness continues through all apertures.

The vignetting is almost the same when you compare f2.8 with f4. But when you stop down the f2.8 version to f4 its almsot gone.

The sharpness in the corners and with subjects far away, the Flektogon 20mm f2.8 is better wide open compared to the f4 version. From f8 there are no significant differences between the both. At f16 the f4 version is almost a little bit sharper.

click the image to enlarge it

Last but not least a comaprison of the “star” both lenses create.

Conclusive opinion

Its hard to tell which of these two lenses is the better one. In my opinion the Carl Zeiss Flektogon f4 is a really good lens for landscape and architecture photography for all Sony, Nikon, Canon, Fuji, Panasonioc (and all others) photographers. When you use a tripod and can stop it down to aperture 8 or 16 there is almost no difference to the f2.8 verison.

Because the f2.8 version is way way better wide open, i recommend this version for astro photography.

Final request

As this is my first “lens review” I would kindly ask you to leave a comment how you liked it. I’d love to read some lines of wishes, criticism and suggestions.


4 thoughts on “Comparison Carl Zeiss Flektogon 20mm f2,8 and Carl Zeiss Flektogon 20mm f4

  1. Lieber Daniel, das ist super geschrieben. Ich bekomme Lust langsam doch mal “Altglas” zu verwenden.
    Gene mehr interessante Fakten! 🙂

    1. Thank you for the feedback.
      1. Yes there were huge clouds passing by. Used the exact same settings and this is what came out.
      2. Nope never heard of that. Thanks for sharing the link

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