Godfrey DiGiorgi wrote:
On Dec 13, 2005, at 10:45 AM, David Oswald wrote:
... An SMC Pentax-M lens doesn't support AF nor does it have an
auto-diaphragm. In other words, it doesn't support auto aperture.
Mounted on one of Pentax's DSLR's, you have to jump through an extra
hoop to get it to meter for you. Many people here don't see this as a
big deal. YMMV.
Previous to that, Pentax had SMC Pentax and Pentax K lenses. They'll
work about the same as a Pentax-M lens. ...
David,
All Pentax K-mount lenses (including M series) have an automatic
diaphragm mechanism.
What the pre-"A" series lenses are missing is the "A" position on the
aperture ring and the electronic contacts needed to communicate with the
*ist DL for fully automatic exposure. With these lenses you use the
aperture ring on the lens to set the desired lens opening, set the body
into Manual exposure mode, and press the AE-Lock button (Green button on
the D model) to meter a scene.
If you want pretty much full functionality, get an SMC Pentax-FA 50mm
f/1.4 or f/1.7. The SMC Pentax-F 50mm f/1.4 or 1.7 is essentially an
equally acceptable alternative.
I agree with that. And, if you are happy enough with Manual focus, an A
series 50/1.4 or 50/1.7 works very well too. But I would strongly
recommend the Pentax FA50/1.4 anyway ... I find this to be a superb lens
for both manual and auto focus operation, with top notch image quality,
resolution and contrast.
Godfrey
Thanks for the clarification, Godfrey. You are right. I was blurring
the distinction between auto aperture, and auto diaphragm, and there
certanly is a difference.
I too have the SMC Pentax-FA 50mm f/1.4, and love the lens. My wife
calls it her lens. Not sure why, except that whenever I grab the camera
after she has used it I find the 50mm mounted on it. :) Strictly
speaking, I've had the lens at least twice as long as I've had her. lol
While on the topic of lenses, I have a love hate relationship with my
16-45. I love it because it's so good that I don't get that feeling of
"I wish I had taken that shot with a prime." I hate it because it is so
good that I can't seem to justify buying standard and wide primes within
its zoom range. It is the only thing standing between me and a 35mm
f/2, a 20mm f/2.8, or a 14mm f/2.8.
