On 3/1/2011 2:37 PM, usher99@xxxxxxx wrote:
> . . .
> I wonder how the Zuiko 500 performace compares to the Sigi 600 CAT.
I've never had a Zuiko 500/8. I'm perfectly happy to believe it has special
qualities. On the simple criteria in the
Modern Photography tests, though, it only stands out for contrast. As has
recently been discussed, and illustrated,
contrast is not the big thing it was in film days before scanners.
Resolution Contrast
_____________ _____________
FL Speed Distortion Falloff Center Corner Center Corner
Zuiko 498 8.27 1.04% pin 0.80 45 40 58 55
Tamron 508 8.00 1.2% pin 0.75 48 36 44 28
Sigma 597 8.35 <1% 0.82 50 40 37 29
Sigma - EQ 500 60 48
The final line is one I find significant. I have both the Tamron 500/8 and
Sigma 600/8. Since I got the Sigma, I
haven't, to my recollection, used the Tammy at all.
The vast majority of the time that I use a mirror lens;
1. My distance to the subject is fixed, or at least can't be shortened.
2. The subject of interest occupies less than the full image area.
Under those circumstances, the longer lens is more effective. The subject is
larger, and less cropping/magnification is
required for the same display image size.
Normal procedure for lens testing is to adjust subject distances equalize
subject magnification on film/sensor. MP uses
the generally accepted 1:40 repro ratio for their tests. However, were they to
shoot the same target, from the same
distance, using 500 and 600mm lenses, the longer lens would , in effect,
resolve 20% higher l/mm.
So - when I carry a mirror lens, it's the Sigma.
> The Zuiko I think is smaller. . . .
Well, in the absolute sense, yes. Per focal length, perhaps not:
FL Weight Length Dia. Vol. Cube Hood Front
Filter Rear Filter Tripod mount
mm g mm mm cc cm
Zuiko 500 590 97 81 500 7.94 Built-in 72mm
Screw-in na na
Sigma 600 756 120 92 798 9.27 Screw-in 86mm
Screw-in 22.5mm Screw-in Rotating
Diff. 20% 28% 24% 14% 60% 17%
Considering the 3D effect of FL on lens volume, and the tripod mount, only a
28% weight increase is pretty impressive.
Of course, the Zuiko weight includes the built-in hood and the Sigma doesn't
include the hood, although it's quite light.
Increase in length and diameter pretty much even out at the 20% increase in FL.
The column "Cube" is the length of the sides of a cube with the same volume as
the lens cylinder. It appears the Sigma
is actually more compact for its focal length than the Zuiko. Again, the hood
differences probably account for that.
My points, from big to more modest:
1. Longer is better for most of my use of teles like this.
2. The Zuiko isn't especially light or compact compared to the Sigma, when
adjusted for FL.
3. For me, the tripod mount is a plus. It adds very little bulk and weight, and
works smoothly and I prefer the balance
on a tripod.
4. Unless one needs 72mm filters for another lens, or already has them, the
Sigma's small, rear filter holder is a real
advantage.
> Perhaps need to search for one of these "monsters" too.
Could be; only time will tell. :-)
Summed Up Moose
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