105 Xenotar & 90 Angulon

[John Hicks]

For the fwiw department, a casual comparison of two old lenses on 6x7, the 105 f 2.8 Xenotar (first purchased by a user in South America in 1956) and a 90 f6.8 A ngulon. Subject was film boxes in a row, photographed from about 10 feet away.

The first "decent" aperture for the Xenotar was f8, with the center getting pr etty crispy while the outer thirds were progressively soft. Sides improved at f1 1, then decent overall at f16.

In case you're wondering, performance is horrible at f2.8 with a _very_ slight improvement at f4, but focusing at f2.8 is wonderful.

For the Angulon, it lagged behind by a stop.

An unintended part of this test involved film flatness. I'd shot a series of s ix on HP5+ in a Graflex RH-10 leverwind back, the let the film sit overnight. Th e next day I shot some infinity-focus shots with the Xenotar; there were no appa rent flatness defects in either the frame that was flat across the pressure plat e overnight or the following four. Infinity remained at infinity, at least at f1 6.

[Erik Ryberg]

I love reading stuff like this. I wish more people would submit their test results. Of course you can never take another person's results as gospel but this kind of thing gives you a really good place to start with your own queries. Thanks very much for posting it. If anybody is interested, I posted a result of a lens coverage test of the 90 mm angulon on www.gnushack.com. Barely gets to the corners of a 5x7 and is pretty soft when it arrives there.

[M.]

Hi John. Your test report makes my glad that you outbid me for that lens. But are you sure that you don't have an imcorrectly located focal plane? I once bought a used camera where the ground glass had been reversed -- drove me crazy! Regards, Mitch

[John Hicks]

> imcorrectly located focal plane

I don't think so; there's no sign of the plane of sharpest focus being ahead o f or behind where it's supposed to be.

[David A. Goldfarb]

I recently picked up a Xenotar 105/2.8 for use with rollfilm backs, and I think it's a pretty decent lens, sharp even at f:4. Mine dates from 1964, and I tested it with a Linhof Super-Rollex 6x7 back on my Tech V 4x5" camera. Here's a sample shot at f:6.8, old TX in PMK, magnification ratio is about 1:4:



http://www.echonyc.com/~goldfarb/temp/Chickering.jpg



and here's a detail at 1000 dpi from my Agfa Duoscan:



http://www.echonyc.com/~goldfarb/temp/Chickeringdtl.jpg



There's something a bit smoother, I think, about the Zeiss 135/3.5 Planar, but the Xenotar is a sharp fast lens that usually goes for a much more reasonable price than the Planar.