Media Technology

This third round of 24mm camera lens testing on the Sony a7R will focus on one item in particular, the Konica Hexanon AR 24mm f/2.8 prime lens. The first priority is to evaluate how much lens curvature interferes with picture quality, by using full width photos from a Sony a7R.

This lens is one of those mythical pieces of Japanese glass, from the halcyon days of film. Internet legend has it that Hexanon lenses were used by the Japanese government, as the standard against which all other lenses were measured. This particular 24mm lens is the latest f/22 version, reputed to have been made by Tokina, for Konica. You can find out more about these Konica lenses at:

http://www.buhla.de/Foto/Konica/Objektive/e24_28.html

Ease of focus at long distances: The focus ring on this lens is well damped, to the point of being stiff, and it has somewhere around 50-55 degrees of rotation. It was fairly easy to focus on the “5610” street number, 3 points.

Lens contrast: Certainly decent, but difficult to compare, since the conditions were cloudy. It’s worth at least 2 points.

Sides of the images: f/8 is a disaster, and f/11 cleans up significantly, but none of it is up to par with the Canon FDn 24mm f/2.8, the current points leader. Zero points.

Center of the images: f/8 is slightly sharper than f/11, look just above the roof on the “5610” street number building.

Summary: This lens goes straight from f/8 to f/11, there isn’t any half-stop detent point, which makes it feel a bit cheap. The addition of the f/22 aperture stop, that the earlier versions didn’t have, doesn’t do much to alleviate that impression. If you look at the lens diagram picture at buhla.de, it appears that there is more curved glass on this lens, verses the previous design. Could that have played a role in the blurry sides we are seeing? The third comparison picture, in the group shot below, shows how much the sides clean up with a very slight misfocus on the center “5610” number. Focusing around like that could be difficult, if not impossible, with the optical viewfinder on a DSLR, but it’s easy with the EVF in the Sony a7R. The question is, can you make misfocusing a part of your shooting workflow, and is it worthwhile? Given that you don’t have to do that with the Canon FDn 24mm f/2.8, probably not, so this lens gets kicked back to the consolation round.

Here is the test image, it’s nearly 13mb in size, **be sure and view it at 100% size**:

https://www.codectest.com/images/24mmLensComparisonKonicaFocusPointTest.jpg

Dan Euritt

24mm camera lens shootout, on the Sony a7R: first round

24mm camera lens shootout, on the Sony a7R: second round

24mm SLR prime lens test, fourth round, shot on the Sony a7R