The sharpest autofocus lens is...a Sigma??

If we're only considering sharpness, it would seem that the Sigma 70mm f/2.8 Macro is actually the sharpest autofocus SLR lens in existence.

Interesting that Sigma can make a lens which is sharper than the best Canon/Nikon macros...

Of course, the Sigma won't autofocus as fast or as nice mechanically, but the sharpness is quite amazing:

Sigma 70mm:

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Take that site with a grain of salt... I mean I have spent some time there before but looking at charts will make you go mad.

Best advice I can give is buy a lens try it out and check out it's sharpness in real world shots for the photography you do and decide from there.

Any chance to put down Canon, huh? Funny that you only posted the 100L results, and no Nikon. You're consistent, i'll say that much.

1Tanker wrote in post #15152215
Any chance to put down Canon, huh? Funny that you only posted the 100L results, and no Nikon. You're consistent, i'll say that much.

Don't be so quick to jump to conclusions next time.

I'm certainly not trying to put down canon. I just think it's interesting the multiple sites tested this Sigma to be the sharpest AF lens out there.

The Sigma is certainly sharper than any of the Nikon macros, as I stated in the original post.

The real reason I did not post the Nikon results is because they were done on a different camera, and so are not directly comparable. In the results above, both lenses were tested on the 5D by SLRGear, and on a 5D 2 by Photozone.

I can already imagine a topic on POTN "This lens is fantastically sharp, but I can't get it to focus at the right place."

Wilt wrote in post #15152217
I can already imagine a topic on POTN "This lens is fantastically sharp, but I can't get it to focus at the right place."

Yep, Sigma's QC is obviously not up to the same level as Canon or Nikon, hence why I had to clarify "if we only consider sharpness" in the first post.

If you look at Photozone's APS-C charts you'll see that the EF-S 60mm is sharper than the Sigma 70mm.

raptor3x wrote in post #15152224
If you look at Photozone's APS-C charts you'll see that the EF-S 60mm is sharper than the Sigma 70mm.

Can you substantiate that statement?

photozone.de says

• FF camera with with the Sigma 70mm has MTF rating of 3736 line-pairs per frame height.
  
• APS-C 15 MPixel camera with the Canon 60mm has MTF rating of 2573 line-pairs per frame height.
  
• And photozone.de carefully prefaces with the disclaimer, "Please note that the tests results are not comparable across the different systems."

Isn't it funny how two endings on words can generate the most visceral of results? 'st' and 'est'

st as in best, worst,

est as in sharpest, fastest, clearest, quickest, flattest...

I'm not the sharpest (there's that damn est-thing again) arrow in the quiver, but I pored over someone else's charts I really didn't truly comprehend before buying a lens, and ended up buying a couple chunks of glass which I thought were good, and bad. But, given that I am not an Adams, or LaRoussech I've been only able to actually say that I was better than one lens in my lifetime. It was the Sigma 28mm f/1.8 and there was just nowhere and nothing I could shoot and obtain a sharp image. Send it back (this was years ago) and it was determined one of the elements was actually installed crooked. So it wasn't that I was better than the lens and my photographic and creative skills has surpassed the lens's ability to render a crisp image, it was that I had a lemon out of the box.

Maybe if I had the best, fastest, cleanest, and strongest lenses available, I would be the best photographer!

Nah, I didn't think so either.

Have a great evening.

996gt2 wrote in post #15152219
Yep, Sigma's QC is obviously not up to the same level as Canon or Nikon, hence why I had to clarify "if we only consider sharpness" in the first post.

Wilt wrote in post #15152217
I can already imagine a topic on POTN "This lens is fantastically sharp, but I can't get it to focus at the right place."

Really ? I have 4 Sigma lens , 2 of which are macro , and they all focus at the right place . They are all built very well also . The 150mm macro is actually very sharp and has a fast AF for a macro ..

I have a the sigma 50mm 1.4.
When I bought it about 1.5 years ago or so, the first one I got had terrible issues focusing, constantly hunting. I got another one and it was very accurate. That same lens on the 5D3 and 1D4 had some back focus issues even with MA, so I took it to the local sigma dealer for recalibration, and they decided to replace the lens for a new one because they had issues calibrating it (their choice, I was told about it only when I came to pick it up).

I also played around with a friend's sigma 150 macro. On his 7D and my 5D3 its spot on without any MA. On the 1D4 it needed a +4 MA for some reason.
My 70-200 and 100L were both tested, and they are both at MA of +0 on both my bodies.
All were tested with the FoCal plus software.

Note that this didn't stop me from ordering a sigma 85mm not long ago. Mainly because the local dealer has very good customer service and a decent price on lenes.

I have the Sigma 70mm macro on a 5D, and yes, it's a very sharp lens, even wide open

Titi

Talley wrote in post #15152187
Take that site with a grain of salt...

Yup, I'm still waiting for the DxO lens test results. Apparently the Canon 75-300 is the best.

Wilt wrote in post #15152344
Can you substantiate that statement?

photozone.de says

• FF camera with with the Sigma 70mm has MTF rating of 3736 line-pairs per frame height.
  
• APS-C 15 MPixel camera with the Canon 60mm has MTF rating of 2573 line-pairs per frame height.
  
• And photozone.de carefully prefaces with the disclaimer, "Please note that the tests results are not comparable across the different systems."

And MTF values depict the relationship between detail resolution and contrast, but make no direct inferrance to 'acutance' which is the characterization of 'sharpness'

Check again, there are APS-C tests for both the EF-S 60 and Sigma 70 on the same body.

EF-S 60mm

Photozone did not report the number of copies they tested. I suspect in many cases, they test only 1 copy and for that reason I find it difficult to trust their absolute numbers. My 100 2.8L is super sharp wide open, noticeably sharper than 70-200 at f4 and 135L but the result of this lens on photozone is not that impressive relatively. In reality I find it hard to believe that any sigma or tamron macro lens can be sharper than Canon 100L on average.

On the side note, the quantitative comparison I trust the most is not from a review side ( guess ? )