Gary's own words on interpreting the test results:
"* Subjective quality factor style grades are relative, with A+ = best,
then B, C, D, and F (worst); differences are significant across full
letter grades only (unless a paired comparison was made - as noted).
Corner grades are measured at 66% out from center and are less rigorous
than center grades. An A+ grade for centers and corners is set to the
performance of a 50mm f/2.0 Zuiko Macro at f/8."
Note that the test of the Zuiko 50/2 and Leica 50/2 Summicron is
described as a paired test "with differences significant at the 1/3
grade level." Of course, the main comparison of interest here (the
50/1.2 Zuiko) is not paired with anything.
Extract of Gary's test data:
50mm f/1.2 Zuiko (multi-coated)
OM-4T with mirror and diaphragm prefire
Vignetting = C @ f/1.2, B @ f/1.5, B+ @ f/2, A @ f/2.8
Distortion = slight barrel (none?)
Aperture Center Corner Contrast
f/1.2 C C+ Mod. high
~f/1.5 B- C+ High
f/2 B- B- High
f/2.8 A- A- High
f/4 A- A- High
f/5.6 B+ A- High
f/8 A- A- High
f/11 B+ A- High
f/16 B+ B High
Notes: Average of three different samples (except contrast grades from
one sample).
50mm f/2.0 Zuiko Macro (multi-coated)
OM-2000 with mirror and aperture prefire, same lens as above
Aperture Center Corner
f/2 B- B-
f/2.8 B- B
f/4 A- A-
f/5.6 A- A
f/8 A+ A+
f/11 A A-
f/16 A- B+
Notes: Moderate contrast at f/2, f/2.8, f/4, f/5.6, f/16, moderately
high contrast at f/8 to f/11. Paired comparison to the Leitz 50mm f/2
Summicron-M in the Other Camera Manufacturer's Lenses section, with
differences significant at the 1/3 grade level.
Leitz 50mm f/2 Summicron-M (4th generation 1978 "Mandler" design,
multi-coated)
Leica M2 with self-timer
Distortion = none
Vignetting = B @ f/2, A- @ f/2.8, A @ f/4
Aperture Center Corner
f/2 B- B+
f/2.8 B A-
f/4 B+ A-
f/5.6 A A+
f/8 A- A-
f/11 B+ B+
f/16 B+ B+
Notes: Moderately high contrast at f/2.8 to f/5.6, and f/16; high
contrast at f/8 to f/11. Paired comparison with Zuiko Macro 50mm f/2.
Leitz 90mm f/2.0 APO-Summicron-M
Leica M4-P with cable release
Vignetting = none
Distortion = none
Aperture Center Corner
f/2* B C+
f/2 B C+
f/2.8 B+ B-
f/4 A- B
f/5.6 A+ B
f/8 A- B
f/11 A- A-
f/16 B+ B
Notes: * = with a B+W filter. High contrast images at f/2 to f/2.8; very
high contrast images at all other apertures.
Chuck Norcutt
On 4/28/2012 8:28 AM, Sawyer, Edward wrote:
>
> What I think about it is his testing regimen was far too subjective
> to draw any meaningful conclusions like that from the data. For more
> objective data, check the workof Modern Photography back in the day.
> I have many of those tests scanned at posted at
> www.edsawyer.com/lenstests
>
> Ed
>
>
> On Apr 28, 2012, at 6:16 AM,
> "olympus-request@xxxxxxxxxxxxxxxxx"<olympus-request@xxxxxxxxxxxxxxxxx>
> wrote:
>
>> [OM] Gary Reese's test of the Zuiko 50/1.2 (really?) To: Olympus
>> Camera Discussion<olympus@xxxxxxxxxxxxxxxxx>
>> Message-ID:<EE5C60DE-9AAF-4B91-81F8-75F5E09406A7@xxxxxxxxxxxxxxx>
>> Content-Type: text/plain; charset="US-ASCII"; format=flowed;
>> delsp=yes
>>
>> Hi All,
>>
>> So, at f/2.8 (a pretty nice aperture to shoot at for subtly
>> shallow DOF), gary reese tested the Zuiko 50/1.2 to be superiour
>> not only to the Zuiko 50mm f/2.0 Macro, but also superior to the
>> Leica M-mount 50mm Summicron, and the Leica M-Mount 90mm f/2.0 Apo
>> ASPH. I find that incredible - what do you guys think about that?
--
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