frieder.faig@xxxxxxxxxxxx-stu wrote:
> Well, coner quality isn`t a real issue to justice this type of lens! They
> are designed to shoot 3D scenes and not to reproduce flat objects ( =
> test board). The lens designer often resign to correct the focus area
> exact even, to get better over all results. When you want exact even
> field (=sharp corners) use a Macro lens.
I do not think you are entirely correct. The 50/1.2 would appear to have
very good performance from centre to edge, going by tests done by
Photography magazine and Modern Photography. In particular, it would
appear to have very much better performance at the edge than the 55/1.2.
The 50/1.4 MC would appear to be a close match for the 50/1.2 but the
latter would appear to have more even performance from centre to edge and
to have better contrast performance on the whole, based on the the first
set of test data below, courtesy of Shawn Weber.
This also is borne out by the Modern Photography tests of the 50/1.2 - the
second set of test data reproduced below. At F8 the contrast numbers are
78 in the centre and 74 at the edge. Looking at their tests of other
Zuikos these contrast numbers would appear to be the highest of just about
any Zuiko they tested!
Of course one shouldn't depend too much on test data, but bar being able
to borrow lenses and try them out ourselves, we haven't much else to go
on, except perhaps George Andersons anecdote about having a photograph
taken with a 50/1.2 published in a National Geographic calendar and the
editor phoning him to ask him what lens he had used ;-)
The test data below does not appear to concur with Gary Reeses tests of
multiple samples of the 50/1.2, where I believe he found a >1,100,000 SN
MC 50/1.4 to have superior resolution, however, I thing the strong suit of
the 50/1.2 is its contrast performance, not outright resolution.
I think Doris could even find a use for a 50/1.2 - wide open ;-)
Giles
-----------Courtesy Shawn Weber---------------------------------------
As a result of some of the questions regarding the performance of the
various Zuiko standards, multi-coated(MC) and single coated(SC), I dug
around in my magazine collection and came up with an issue of
Photography(March 1983) that tested out all six Zuiko 50s. I shall
summarise the results below :
Key : C=Centre, E=Edge, Hi=High contrast target, Lo=Low contrast target
Results are cycles per mm
55/1.2(SC) C/Hi C/Lo E/Hi E/Lo (7 elements/6 Groups)
1.2 36 21 24 18
2 54 33 27 27
2.8 60 42 30 30
4 66 42 36 36
8 66 48 36 33
Tester's comment: Distortion low, flare not as good as 50/1.2
50/1.2(MC) C/Hi C/Lo E/Hi E/Lo (7/6)
1.2 42 36 42 30
2 60 42 48 36
2.8 66 54 54 48
4 72 60 66 54
8 66 60 72 60
Tester's comment: great performance regardless of speed, distortion,
flare low
50/1.4(MC) C/Hi C/Lo E/Hi E/Lo (7/6)
1.4 54 42 48 33
2 60 48 48 33
2.8 72 60 60 48
4 72 54 54 54
8 72 66 54 54
Tester's comment: Very good overall performance, good flare resistance,
mild barrel distortion.
---------------------------------------------------------
Modern Photography
50/1.2 MC (11/83 p. 131): Resolution (lines/mm) at 1:50x
1.2 2 2.8 4 5.6 8 11
16
Center: VG 45 Gd 50 Gd 56 VG 63 VG 63 VG 63 VG 56 VG 56
Corner: Ex 35 Ex 40 Ex 45 Ex 50 Ex 56 Ex 56 Ex 50 VG 45
Contrast (%) at 30 lines/mm
Center: Hi 58 Hi 60 Hi 64 Hi 68 Hi 76 Hi 78 Hi 75 Hi 67
Corner: Med 26 Med 30 Hi 44 Hi 60 Hi 73 Hi 74 Hi 66 Hi 81
--------------------------------------------------------
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