[rollei_list] Re: Sweet spot: f8/f11?
- From: CarlosMFreaza <cmfreaza@xxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Sun, 23 Oct 2011 09:37:37 -0300
2011/10/23 Marc James Small <marcsmall@xxxxxxxxxxx>:
>
> I would approach any camera magazine test of lens quality with a bit of
> caution. Burt Keppler was a good commentator but, then, he was also a man
> of pronounced biases.
Yes, I agree, any lens test needs to be taken with caution, anyway
"Modern Photography" had a good optical bench to test lenses at the
time, those tests are valid for the specific lenses they tested of
course, however the test shows a very similar performance for Planar
and Xenotar 2.8/80 (between them) and 3.5/75 (between them) when
camera and lenses were new indicating the performances seemed to be
within the Rollei specs.
> The Carl Zeiss MTF data seems to set out that the 2.8/80 Planar used in the
> GX and FX cameras achieves its best performance from f/5.6. I am not aware
> of similar scientific tests done on the earlier versions of this lens or on
> the Xenotar. In my personal experience, both lenses as used in the 2.8F and
> earlier cameras peak from f/8 but, again, my own experience is hardly any
> more a scientific test than were the musings of Burt Keppler.
Yes Marc, my experience with the Xenotar 2.8/80 indicates that this
lens achieves the best performance from f/5.6 too, however there are
performance differences from f5.6 to f22 for every f/stop, at f22
performance decreases more significantly due to refraction issues.
Carlos
---
Rollei List
- Post to rollei_list@xxxxxxxxxxxxx
- Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe'
in the subject field OR by logging into www.freelists.org
- Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with
'unsubscribe' in the subject field OR by logging into www.freelists.org
- Online, searchable archives are available at
//www.freelists.org/archives/rollei_list
Other related posts:
