Creating a 28-135mm around 1985 was a difficult task, especially when the lens was aimed at demanding professionals. Canon didn't have one (just a 35-105mm), Nikon wisely limited itself to 35-135mm and 35-200mm lenses, and Minolta had just introduced their groundbreaking autofocus 4-4.5/28-135mm lens. Pentax had their 4/28-135mm introduced in 1984 (a pretty mediocre lens), and then there was Tamron with the SP 4-4.5/28-135mm, introduced in 1983. Now bring in Konica and Tokina ...

The Konica AR 4-4.6/28-135mm is a pretty heavy superzoom computed by Konica and manufactured by Tokina. The lens certainly is one of the most complicated vintage MF lenses ever built, as it has 18 elements in 12 groups. The lens has five (!) independently moving groups. Unlike the Minolta AF 28-135mm, which uses a small group at the rear of the lens fro focusing, the Konica 28-135 is focused by moving two front groups independently. This has the advantage of a variable minimum focus distance (MFD). At f=135mm the MFD is 1.5 m, at f=80 mm it is 0.8 m, and in the 28-35mm range it is 0.5 m. Focusing from infinity to 0.5m takes only about 90°, and it "steepnes" is variable as well. Sounds complicated? Manufacturing must have been a nightmare, but the Minolta 28-135mm was a difficult-to-manufacture lens as well (allegedly sold for less than its production price).

The barrel is pretty well made - everything (at least at the outside) is metal, focusing is a bit stiff but precise, and the aperture ring turns reasonably easy (thank you, Tokina!). While my lens looks like new (and was new pold stock when I bought it), something must have come loose inside since I hear a slight "wobble", and objects at infinity are completely unsharp when using the wideangle setting. In addition, using the lens at cold temperatures has caused the front doublet to separate. Therefore all further remarks about the prefomance of the lens refer to test results from my Tokina AT-X 4-4.6/28-135mm!

At f=28mm, the Konica / Tokina has more CAs and less corner resolution than the Minolta and the Tamron. Center resolution is excellent for all lenses even at f4.

At f=50mm the Konica / Tokina improves - less CAs and better corners wide open, but the Minolta still is slightly better. Tamron is similar to Konica, but has nearly no CAs. Center resolution is excellent for all three lenses, again.

At f=90mm the Konica is at its peak - especially at f11 the entire image is really sharp, and no CAs are visible. The Minolta has an even better resolution (particularly at f5.6), but some traces of lateral CAs as well. The Tamron now is slightly weaker than the other two lenses.

At f=135mm CAs start to kick in - on all three lenses. Wide open, the Konica has quite soft corners - it clears up at f11. The Minolta has similar problems wide open, but is pretty much OK already at f5.6. The Tamron now struggles; even at f11 the corners and bordes are missing some detail.

Oh, and I forgot about the Pentax. Forget it, I must say. It's clearly inferior to the three lenses above, and I mean clearly. That's not due to a "lemon": Other users in the net are claiming the same.

KONICA HEXANON 28-135mm 1:4-4.6                 (18 Linsen / 12 Glieder)

* frühes "Superzoom" (ca 1983)

* Schiebezoom
* 18 (!) Linsen
* gerechnet von Konica, gefertigt von Tokina (später auch als Tokina AT-X 28-135mm für andere Anschlüsse lieferbar)
* wie üblich bei Konica-und Tokina-Objektiven sehr massig gebaut; geliefert inkl. Metall-Deckel und Metall-Sonnenblende

* Naheinstellgrenze von 0.5m (bei f=28mm), 0.8m (bei f=85mm) und 1.5m (bei f=135mm); deutlich praktischer als beim Minolta AF 28-135mm (1.5m über den ganzen Bereich)
* Filterdurchmesser 67mm

* offen bei f=28mm sehr unscharfe Bildecken, abgeblendet OK
* bei f=70mm offen in den Ecken eher unscharf, sonst OK
* bei f=135mm recht detailreich
* alles in allem einigermassen brauchbar, aber nicht so gut wie das (spätere) Minolta AF 4-4.5/28-135mm