John Hicks
6-Aug-2000, 23:46
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.
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.