IQ verdict needed quickly please!

[Kermit power]

Over here, I was querying what sort of zoom to get second hand, and eventually decided on giving a Sigma 70-200mm f/2.8 a go.

When I got it this morning and had a quick play with it, I was rather underwhelmed, to put it mildly. This afternoon, however, I've had a bit more of an opportunity to try it out, and I'm not so sure any more.

The shot below was taken at f/2.8, ISO 100 1/80th sec and 159mm zoom with a tripod and remote shutter release. I've done absolutely nothing to it either in the RAW conversion or in Elements - the exposure, contrast, white balance, clarity, saturation and the like are all exactly as they came out of the camera. The first is the whole image, and the second is approximately a 100% crop, assuming Photobucket will display it as such.

I'm still not stunned by the image quality, but to be fair the weather is still pretty murky and grey. Am I being unfair in questioning the lens quality, or should I be concerned? I could wait until nice bright conditions return, but by that stage, it might be too late to take it up with the guy I bought the lens from on Ebay. Please could some of you experts let me know if you think I'm just expecting too much, given the weather?

[ThatPhilBrettGuy]

Looks ok to me. A 100% crop from one of the corners might be more telling.

[Kermit power]

ThatPhilBrettGuy said:

Looks ok to me. A 100% crop from one of the corners might be more telling.

That's maybe slightly unfair, as the stuff in the corners wasn't at exactly the same distance from the camera as the sign, which was the point of focus, but this one is probably the closest...

[_dobbo_]

You don't really say what you were expecting from the lens. What isn't it delivering that you thought it would?

[Kermit power]

_dobbo_ said:

You don't really say what you were expecting from the lens. What isn't it delivering that you thought it would?

The shots I took this morning seemed horrifically soft at f/2.8. These ones look better, so now I'm questioning myself as to whether there's an issue or not? I don't think the focusing is off, but do people think the sharpness is good?

[ThatPhilBrettGuy]

Not bad in the corners either. Lenses are never at their sharpest wide open anyway. Best test to negate focus issues is to use LiveView zoomed to the max, manually focus then see.

[SamHH]

Maybe have a look at others' photos or post your own here:

http://photography-on-the.net/forum/showthread.php...

[Gemm]

This is where I thought was the major difference between the Sigma and Canon. The Sigma copy I had wasn't quite as sharp as the Canon wide open. So I often had to stop down to f4 or 5.6, but I can shoot without any hesitation at f2.8 with Canon. AF is significantly better too.

Edited by Gemm on Wednesday 25th February 20:40

[Colin RedGriff]

I'd have said try it at a higher aperture. Most lenses won't give their best at the limits of zoom and aperture.

Give it a try again at something like f9.

[Gemm]

Colin RedGriff said:

I'd have said try it at a higher aperture. Most lenses won't give their best at the limits of zoom and aperture.

Give it a try again at something like f9.

But the whole point of getting a f2.8 lens is to be able to shoot at f2.8?

[Colin RedGriff]

Agreed it is. I'm not saying you can't shoot at f2.8, just that to get the sharpest image then he should try a higher aperture.

There's always a trade-off

It's like ISO values you can shoot at ISO 1600 to keep the shutter speed high but you trade that with increased noise.

[Gemm]

Colin RedGriff said:

Agreed it is. I'm not saying you can't shoot at f2.8, just that to get the sharpest image then he should try a higher aperture.

There's always a trade-off

Yes, this is true but I think this is definitely where there's a difference between a good lens and an average lens. But this often comes with a good price tag too.

[Kermit power]

Gemm said:

This is where I thought was the major difference between the Sigma and Canon. The Sigma copy I had wasn't quite as sharp as the Canon wide open. So I often had to stop down to f4 or 5.6, but I can shoot without any hesitation at f2.8 with Canon. AF is significantly better too.

I don't doubt that the Canon f2.8 L is a stunning lens, but it's also well over twice the price of the Sigma, so wasn't up for consideration. It was either the Sigma 2.8 or the Canon 4.

I am increasingly though accepting that this morning was an exception. The shot below is cropped to roughly 50%, and I've sharpened it up a bit. For such poor light, I'm happy with this. Not sure why it's gone so small in Photobucket though!

[RobDickinson]

Shoot a proper test subject which is flat at f2.8 across the whole frame, also do a focus test.

more likely its misfocusing that soft.

But those dont look too bad, remember raw does need sharpeing some too.

My sigma 70-200f2.8 is plenty sharp enough to be usable wide open without worry, focus though is tricky.

Edited by RobDickinson on Wednesday 25th February 21:10

[VxDuncan]

RobDickinson said:

Shoot a proper test subject which is flat at f2.8 across the whole frame, also do a focus test.

more likely its misfocusing that soft.

But those dont look too bad, remember raw does need sharpeing some too.

My sigma 70-200f2.8 is plenty sharp enough to be usable wide open without worry, focus though is tricky.

Edited by RobDickinson on Wednesday 25th February 21:10

Spot on. At the longer reaches and F2.8 the AF has to be spot on. I know what a difference AF errors can make when I got the AF Fine tune setting wrong on mine. What body is this on?

Those images look fine as said, esp as there's no sharpening. I'd be happy with that performance in crap light at 1/80 s (even on a tripod)

[Kermit power]

VxDuncan said:

What body is this on?

It's on a 450D.

[Pixel-Snapper]

Chris,

I'm interested to hear how you get on over the next few weeks with this lense im in the same boat mate looking for a 70-200mm to take to Lemans but want the biggest F-stop i can afford and the canon 2.8 is way out of my budget.

Do you mind me asking what you payed for it on flebay?

was it second hand if so do you know how old it is?

feel free to PM me.


ow PS shots look good to me.

Edited by Pixel-Snapper on Thursday 26th February 14:19

[Kermit power]

Pixel-Snapper said:

Do you mind me asking what you payed for it on flebay?

was it second hand if so do you know how old it is?

It was £301. They usually seem to go for around £360-370 from what I saw, but this one has a slight crack on the filter ring, although it's purely cosmetic rather than functional damage, so that knocked the price down somewhat.

The second hand Canon 2.8 lenses I watched on there were mostly in the £650+ price range.

[Pixel-Snapper]

Kermit power said:

Pixel-Snapper said:

Do you mind me asking what you payed for it on flebay?

was it second hand if so do you know how old it is?

It was £301. They usually seem to go for around £360-370 from what I saw, but this one has a slight crack on the filter ring, although it's purely cosmetic rather than functional damage, so that knocked the price down somewhat.

The second hand Canon 2.8 lenses I watched on there were mostly in the £650+ price range.

Well it is a small world, I was watching that same one but couldnt bring myself to bid on it with the crack in, so it wasnt as worse as it looked then bugger!. Well im glad that it went to another PHer and we didnt have a biding war over it.

Enjoy and please post some more examples im still on the hunt on ebay.

Edit for typing to fast

Edited by Pixel-Snapper on Thursday 26th February 14:51

[Kermit power]

Pixel-Snapper said:

Well it is a small world, I was watching that same one but couldnt bring myself to bid on it with the crack in, so it wasnt as worse as it looked then bugger!

That's why I've been so quick to get out taking shots with it. I wanted to be sure it was fine internally!