# Sigma UltraCompact Macro Zoom MC 70-210mm f/4-5.6 (for pentax k mount) any good?



## Caldas (Jun 5, 2014)

Hey guys,I've just bought a new lens to use on my Pentax K1000 mainly because it was cheap and looked decent enough (30 USD on ebay), do you guys have any experience with older ultracompact sigma lenses? I'll add some pictures (that the seller provided) to make it easier to identify.​
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## Derrel (Jun 5, 2014)

I have a Sigma of the next era, a 70-210mm f/4~5.6 autofocus, but in most ways size-wise it looks a lot like that one, but for Canon. It's "okay". Has a little "purple fringing" at the long end, on some subjects, but not too bad. Lenses of that specification are not that challenging to design or build. At f/5.6 and f/8, it's probably close to the equal of camera-makers lenses that used to cost 4x as much. What made those Sigmas nifty WAS the ultra-compact length they were able to achieve! MOST earlier 70-200 or 70-210 or 70-205 zooms were significantly longer, like 30 to 50% longer when compacted to their shortest overall length.


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## Caldas (Jun 5, 2014)

Derrel said:


> Has a little "purple fringing" at the long end, on some subjects, but not too bad


So do you think that if I leave it at 150~180 I can eliminate some of the fringing?


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## Derrel (Jun 5, 2014)

It shows up mostly on strong, high-contrast subjects like tree branches against bare sky and stuff like that. In normal use, or with smaller prints like 4x6 color prints, the fringing is not really that big of a deal. But yeah, it seems worst at the long end. I bought the lens on a Canon Rebel film camera, and shot it on my 20D digital, and the fringing was really the only issue I noticed--except that the "chip" in the lens was not up to standards for a d-slr-era camera, so the lens "err99"'d out a lot on the d-slr, but it is FINE on a film camera.

It's really not that big a deal on "most" subject matter, but I could see that was the lens's biggest problem issue. It was amply sharp, and focuses easily and well. And again, on a d-slr, I was looking at BIG images on-screen on a 30-inch wide monitor; on a 8x10 print, that's not going to be a deal-breaker. And for $30...that's about what a lens like that goes for.I would definitely shoot something like say a bare (no leaves) tree against a white sky, or telephone wires or chain link fencing against a white sky, and you can see the color fringing, but then shoot a "real picture", not with everything silhouetted against the sky, and you'll see that the color fringing issue becomes a LOT LESS of a real issue, and more of just "it is there, but not that meaningful". Like dead summertime bugs on your car's front bumper...yeah...they're there, smashed and dried on...


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