Almost flawless! 35mm f/2 IS USM review

Great Bustard wrote:

qianp2k wrote:

Jonathan Brady wrote:

qianp2k wrote:

Good review!

Thanks!

However I disagree your conclusion that Sigma 35/1.4 Art @F1.4 is sharper than 35/2.0 IS @F2.0. You might have a soft copy.

I don't dispute that as a possibility.

DPR 35/2.0 @F2.0 IS vs 35/1.4 A @F1.4 on 5D2

DPR 35/2.0 IS @F2.0 vs 35/1.4 A @F1.4 on 7D

TDP 35/2.0 IS @F2.0 vs 35/1.4 Art @F1.4

In either case, it shows 35/2.0 @F2.0 is sharper than Sigma 35/1.4 Art @F1.4. At F2.0, Sigma is sharper. Canon captures up at F2.8 and as sharp as if not slightly sharper at F4.0.

PZ tells a different story...

http://www.photozone.de/canon_eos_ff/848-sigma35f14eosff?start=1

http://www.photozone.de/canon_eos_ff/847-canon35f2isff?start=1

MTF charts show the Sigma resolving 3587 lines at f/1.4 and the Canon 35IS resolving 3069 at f/2. It's possible their copy of the Sigma is REALLY good, the 35IS is a soft copy, or both. Same for me.

This is a major disagreement between me and a few regarding PZ Tests that I found that they are not reliable and not very scientific. I trust DXO, LensRentals far more.

LensRentals also found 35/2.0 IS @F2.0 is sharper than Sigma 35/1.4 Art @F1.4. So I have to believe the other three tests - DXO, TDP and LensRentals but not PZ. I'd suggest you to get another copy and test again.

http://www.lensrentals.com/blog/2012/12/another-35mm-lens-for-canon

...doesn't that show that that at f/2, the Sigma is sharper across the frame (9% higher in the center and 40% higher in the corners)?

That is not what I disputed but actually what I agreed upon if you read. I only dispute on Canon at F2.0 vs Sigma at F1.4 that all other 3 reviews and the video don't show latter is sharper. I personally don't care much in corners at a lens' wide open (any lens' wide open) that I wide open lens for the two reasons - low light (don't care dim corners such as in a building) and portrait (softer corners/edges actually help to popup subject better).

Whether or not that sharpness matters, of course, is another matter all together, just as whether f/1.4 matters more than IS, or vice-verso, is also another matter all together.

As I said in my usage, 35/2.0 IS doesn't not have sharpness disadvantages than Sigma 35 Art in low-light hand-held on static or slow moving subjects (I don't use this lens to shoot sports or fast moving subjects). By stopping down to F2.8, 4-stop 'IS' effectively overcome sharpness advantage of Sigma 35 Art at F2.0 and likely Canon at F2.8 still ended at lower ISO (or at least at the same ISO) than Sigma at F2.0 or F1.4, therefore likely ended in better IQ. By this regard in my usage, I don't see I actually sacrificed optical quality in picking up 35/2.0 IS instead of Sigma 35 Art. But if you shoot lots at F1.4, then no contest, just not in my usage for a 35mm prime lens.

The difference between 35/2.0 IS and Sigma 35 Art is different from between 24-70L/2.8 II and 24-70L/4.0 IS. As in former case, by stopping down to F2.8 or F4.0, the lenses basically have the same sharpness, Canon copy is even very slightly better in bokeh and slightly faster in AF while in latter case, no matter how you stop down, 24-70L/4.0 IS is never better than 24-70L/2.8 II (as a matter of fact, 24-70L II at F2.8 is sharper than 24-70L/4.0 IS at F4.0 cross entire FL).