Sigma UC Zoom 70-210mm 1:4-5.6

[parabellumfoto]

I bought one of these on Saturday.

I still don't know what to make of it. Sometimes its okay-ish and other times it is pathetic.

It glows in sunlight. CA seems to be bad. At f8 it seems to sharpen up and also at certain focal lengths and distances.

I've taken a ton of shots - most of them bad. Either they are out of focus or glowing too much.

This is manual focus on my Nikon D3200 but I still get to control the aperture automatically through the camera.

[parabellumfoto]

[parabellumfoto]

The lens seems to like birds at close distances. This Australian Myna was about two metres away from me.





These have been resized but I hope you can see the detail. Looks reasonably sharp. Colour is nice and it seems to shoot well in shade.

[parabellumfoto]

The sharpest bee shot I have managed to take with this lens and it still looks a touch soft.



Notice the glow on the far flower petal?

[parabellumfoto]

The flower in this shot looks fairly sharp.

[parabellumfoto]

Long distance shots seem ok

[parabellumfoto]

Here's another.

It's in focus but something does not look quite right. The leans doesn't seem to be able to resolve the image quite right.

This is 100% crop.

[buerokratiehasser]

Yes, I couldn't put my finger on it either.
There is some haze, or microglow, or whatever.

It does resolve fine details like twigs on horizon but it all looks unsharpy, or film if you want.

Maybe it's just very low contrast and microcontrast/MTF.

This lens is generally regarded as donotbuy, also mine literally broke, it is now a 180/5 after gumming it up with tape.

[buerokratiehasser]

Um yeah I made some 1:1 crops some time ago

http://fototalk.de/album_pic.php?pic_id=75634
http://fototalk.de/album_pic.php?pic_id=75635
http://fototalk.de/album_pic.php?pic_id=75636

(unfortunately the filenames were mangled by the uploader. That's 100% crop 10Mpix APS-C, F8/F9)

[parabellumfoto]

[buerokratiehasser]

It may be microblur, or even microCA (when looking 200% zoom at the 1891 1991 post and the small wires), something is smearing, high contrast details still get resolved like the microhairs on the flies, but it's just not impressive.

I also experienced that quite many shots (AF version) were out of focus, maybe due to the rough mechanics of that thing - the gears may also have been damaged from the start, giving some way to tolerances. This shouldn't be important with your MF version though.

[philslizzy]

The lack of contrast, to me, indicates perhaps there is something in the lenses??

I dropped an AF Sigma 80-300 in the sea and rinsed it out in fresh, boiled water and let it dry slowly for about 2 weeks. I lost some contrast but couldn't see anything in the lens itself. I got a softness too.... Eventually the lens ground to a halt literally, the aperture stuck and the focus got rough. It ended up in a Spanish dustbin.

[buerokratiehasser]

Hrmm, I went through some shots again and some were, resolution-wise, not that bad. Both bird and horizon. I think you need F9 or worse and really contrasty target (full sun on overdrive would be nice, or flashhhhh), and spot-on focus. Many of the unsharp shots I got with this one are probably damaged/too fast AF missing by some inches.

Yeah but it's still do not buy unless for a buck or if you really need a tele and can't afford better, 5-10 bucks. The colors, contrast always look a bit like you're filming a TV screen, and while it's better than no tele, sticking a 75-200/4.5 or 60-300/4-5.6 umcs (@210) on your kit provides for immediate fun - you just know when looking at the images.

[parabellumfoto]

[buerokratiehasser]

People from another forum also experienced overexposure and said the rom was bad.
Now the rom on M-AF doesn't do anything. Except telling the camera focal length, lens ID and the aperture-to-aperturelever curve.
That would mean F8 isn't really F8. Which is not so good.

Don't know how it works on Canon.