The Vivitar 24 mm f/2.0 is a very fast wide angle lens produced for different mounts. My copy was manufactured by Kiron (a brand of Kino Precision) and there is at least one other version of the 24 mm that was produced by Komine. It is disputed, which version offers better image quality. The Kiron version, however, is known to have problems with an oily aperture.
The short lens feels effortless on the NEX-5T and handles very nice. The effective focal length of 36 mm makes this lens predestined for everyday carry. The fastest f/2 aperture should be seen as an emergency stop for regular shots, though, as heavy blooming will appear in contrasty situations. But this may also be an advantage, if you’re specifically looking for that soft and glowy performance many appreciate in vintage lenses.
Condition of my copy
Optics: Good. One 5 mm scratch in the outer third of the front element. A handful of lonely dust particles inside. Fungus behind the first lens element that has been removed and left not trace.
Mechanics: Very good. Smooth focus, aperture clean and fast but had to be cleaned from oil.
Exterior: Excellent. Only slight signs of use on the mount.
Optical performance on NEX-5N / 5T
Hazyness and softness at f/2 are accompanied by relatively low contrast which, combined, give a rather flat picture. At f/2.8, the haze mostly disappears and contrast improves heavily, but the image still lacks sharpness. F/4 to f/8 are clean and show good contrast, but stay a tiny little soft. From f/11 on, diffraction further softens the image.
Chromatic aberrations are visible but not too apparent at f/2 and f/2.8 due to hazing. Heavy red and cyan CAs become clear at f/4 and grow further as the lens is stopped down. All in all, one of the worse CA performances I have seen. Luckily, the CAs present in a form that is easy to correct in post processing.
Vignetting is about 1/2 stop at f/2, improves massively at f/2.8 and is gone by f/4. The effective T-stop at f/2.0 is approximately T2.6 (-0.8 EV), which is pretty bad. The lens also shows a medium to strong barrel distortion of -1.5%.
The 24 mm f/2 performs very similar to the Kiron 28 mm f/2, especially CA-wise. The latter outperforms the 24 mm in terms of sharpness and distortion. This Vivitar is best used in conditions where the CAs don’t stand out and critical sharpness isn’t your main concern. As a fast reportage style focal length on APS-C, it qualifies for dim lighting conditions and indoor shots, where the image noise kills more details then the lens anyway.
The following images are pixel-level crops from the test chart. They may appear scaled in your browser window. Click on them to view the crops in full size and cycle through them easily. For more info on the test setup, visit the details page.
(Cropped areas marked in orange)