Bad 70-200 =(???

i Really think this is too soft Even for the Sigma F/2.8 70-200....

had this since september 23, Should i ask for another copy?

First one is F/2.8

Second is F/4.5

third is F/8

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3rd

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I don't know if this is representative for this lens, but in absolute terms, that f/2.8 image looks poor (and under-exposed). f/4 is pretty sharp, and the f/8 is great. There could be a very slight back-focus, but I don't think it would be a problem in nomal use.

See what others who have this lens say about the 2.8.

You are not using the focus chart right. To correctly indicate whether that focus is off you need to set the camera up on a tripod at 45° from the piece of paper, which is on a VERY flat surface. You can be a bit off 45° but try and be as close as possible.

Use Mirror Lock Up with a remote release if possible to reduce any camera shake and mirror slap.

Try that and post your results.

All three shots are almost unusable for focus testing.
f/4.5 and f/8 should be deleted, they tell nothing and f/2.8 is hardly usable.

Focus test should be done at the widest aperture at the angle of (roughly) 45 degrees.
If they are shot from right above (as in this case) focus accuracy is hardly visible.

F2.8 on this lens is fairly sharp, but not tack... Do some real world tests and post back.

Is this Focus test or Sharpness test?

Hermeto wrote in post #4294272
Is this Focus test or Sharpness test?

Yeah, thats what I was wondering too. I just assumed a focus test because of the chart.

Probably better to post this in the lens talk forum.

He's probably trying to test for sharpness.. perhaps inadvertently thinking that's what the focus chart was for.

To the OP: What are your images like? Suppose your copy exhibited the performance demonstrated with that f/2.8 shot (and that your technique wasn't really flawed).. how come you took so long to realise? It's often not good to wait so long before trying to exchange it.. you might find the best Sigma/your retailer might do is try to repair it.

How do your normal, everyday pictures look?

The OP is suspecting eccessive softness.

Even so, it's not a bad idea to check with a focus test chart, so as to be able to tell how much of it is real overall softness and how much it's a result of front/back focusing. Both issues can lead to just unsharp main subjects.

Anyway, the test should be done under 45 degrees, as everyone is suggesting.

Well, i did see people complaining about 2.8, but its too excessive to me, and ill take some more test shots in incandesent light (i think its spelled that way)

Ps: all my shots were taken on a tripod, and sorry for the section mistake, happens ^^.

Here we go.

Same order as before.

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3rd.

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Adamora, do a focus test with that sheet. That sheet is designed for testing focus, not sharpness - basically, you're not using it correctly. Read the instructions and you'll notice you should be focusing on the sheet at an inclination of 45 degrees.