I have no personal knowledge of the Tamron, but I do recall Winsor's
repost of an old post showing that Vivitar & Tokina 17/3.5s were
significantly poorer performers than the major camera manufacturer's
lenses, so don't assume what Walt found with his Tamron applies to those
others. Original post copied below.
Happy owner of the winner,
Moose
Brian Swale wrote:
Hi Walt & co,
Thanks for the endorsement of the Tamron 17/3.5.
Very useful to know it is so sharp. Presumably the other characteristics are
OK as well.
----------------------------
Winsor Crosby wrote:
I thought I might recycle an interesting submission from the past.
Richard Schaetzl was a list member who always had something interesting
to say.
Ladys and gentlemen,
here are some reasons, why you shouldn´t sell your 18mm Zuiko,
congratulations to the buyer.
Based on a lens test by the Magazin Color Foto, published in 9/89, 11/89.
...and the winner is:
Lens Sharpness Contrast Distorsion Vignetting
---- ---------------- --------------- ----------- ----------
Stop Cen. Cor. Tot. Cen. Cor. Tot. in stops
Olympus Zuiko Auto-W 18mm 3,5
3,5 8.4 7,3 8,0 9,0 7,8 8,6 waveform, 2,6
5,6 8,5 7,6 8,2 9,3 8,1 8,9 slightly to 1,7
8,0 clear 1,3
Contax Zeiss Distagon T* 18mm 4,0
4,0 7,6 6,4 7,2 7,9 6,9 7,6 barrel, 2,3
5,6 8,7 6,8 8,1 9,0 7,6 8,5 slightly to 1,7
8,0 clear 1,4
Leica Elmarit-R 19mm 2,8
2,8 8,4 5,4 7,4 8,6 6,6 8,0 waveform, 2,6
5,6 9,2 6,4 8,3 9,3 7,6 8,7 slightly to 1,5
8,0 clear 1,2
Nikon Nikkor 18mm 3,5
3,5 8,0 6,9 7,6 8,5 7,4 8,1 waveform, 2,6
5,6 8,6 7,2 8,1 9,2 7,9 8,8 slightly to 1,6
8,0 clear 1,2
Canon FD 17mm 4,0
4,0 7,4 6,1 7,0 8,3 6,4 7,7 waveform, 2,3
5,6 8,1 6,6 7,6 8,9 7,6 8,5 slightly to 1,5
8,0 clear 1,2
... and now some really bad performer.
Vivitar 17mm 3,5
3,5 6,7 3,1 5,5 6,2 3,6 5,4 waveform, 2,4
5,6 8,3 4,7 7,1 9,1 6,8 8,3 clear 1,5
8,0 1,3
Tokina SL 17mm 3,5
3,5 7,7 5,4 6,9 7,7 5,2 6,9 waveform, 2,3
5,6 9,0 6,7 8,2 9,3 7,9 8,8 slightly to 1,6
8,0 clear 1,4
If somebody complains, that the test is pretty old and new lens designs
migth be better, to whom I like to tell, that CoFo tested recently the new
18mm 2.8 AF-Nikkor and it showed,that the old 18mm 3,5 Nikkor is
slightly better. Neither Leitz(Leica) nor Zeiss have changed there lens
design since.
Remarkeble is the high performance of the Zuiko with wide open aperture,
stoping down has not much influence on sharpness and contrast.
Interesting is the difference in quality of the Tokina and Vivitar
lenses, as far as I know, they are the same design. I owned the Vivitar
lens and
found it a quite decent lens (this means either my standard for quality
is low :-( or i got a better lens they send to the test :-) or even
better the Zuiko is supernaturely good =8-O ).
The quality numbers are basing on MTF measuring, the difference of one
whole number marks an, for the critical observer, just noticable
difference in sharpnes, contrast. The maximum number is 10, which stands
for a flawless lens. The number are computed and weigthed for the
central half diameter
to 2/3 and the rest to 1/3, the extrem corners are not rated. Vignetting
is the combined effect of light fall off and vignetting through the lens
barrel.
Waveform distortion is a combination of pincushion distorsion in the
corner and barrel distorsion in the center.
Richard
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