I've been 'listening' to this endless chatter about Albert's 28/2.8 with
half an ear. It occurs to me that there are 2 questions I haven't
noticed being asked.
1. Is it SC or MC? It appears from the SIF that the 28/2.8 came as both,
although I've also heard it is only MC.
2. Was it used with a 'protective' filter, like a Skylight or UV filter?
A bad filter can make a good lens look bad and you can't tell about the
filter just by looking at it.
All 'testing' of lenses should be done without a filter first or with a
filter vs. non filter comparison.
This is from Gary Reese's lens tests:
50mm f/1.4 Zuiko (multi-coated)
OM-2000 with mirror and diaphram prefire; lens with >1,100,000
serial number
Vignetting = D @ f/1.4, B @ f/2, A- @ f/2.8, A @ f/4
Distortion = none
No filter
Aperture Center Corner
f/1.4 B B
f/2 A- B
f/2.8 A A-
f/4 A A
f/5.6 A A-
f/8 A- A-
f/11 A- A-
f/16 B+ B+
Notes: High contrast, except moderate in center at f/1.4, moderately low
in corners at f/1.4 and moderate in corners at f/16; remarkably even
performance across all apertures.
With poorly made Vivitar VMC ND3 neutral density filter
Aperture Center Corner
f/1.4 C- C
f/2 C C
f/2.8 B B
f/4 B B+
f/5.6 A- A-
f/8 A- A-
f/11 A- A-
f/16 B+ B+
Notes: Differences are significant at the 1/3 grade level in this paired
comparison evaluation. Contrast was slightly lower with the filter, but
lower resolution was the most important factor in image deterioriation.
Please note that this particular filter is not indicative of Vivitar or
Vivitar VMC filters, in general. It just tested as a poor sample. Other
filter makers, even the most highly regarded, have been found to have
poor samples in selections taken from used and new stocks of filters.
The use of the term "poor" means star test images, viewed on
a vertical auto collimeter, which show images that are: multiple and
overlapping, fuzzy, off center, and images which rotate when the lens
is rotated. More often than not, only one of these faults are found in
an examined filter. These filters (including the test filter) often look
perfectly good when examined without the aid of instrumentation!
OT-Philosophy content: You can't tell a lens by it cover.
Moose
Olympus wrote:
I do keep that in mind Chip, so I'm getting rid of "this" 28mm/2.8, not
going to throw the baby out with the bathwater.. It doesn't mean I think
all Zuiko's suck, and will never buy one again.. But it's my hopes that my
28mm or 24mm will be razor sharp... regardless of brand..
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|