Great Bustard wrote:
qianp2k wrote:
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.
Ah.
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).
In general, I agree that sharp corners wide open are not a big deal. There are times they are important, such as astrophotography, but other times they are important, IS matters more.
Why someone shoots astrophotography in wide open?
However, as to whether or not soft corners are a benefit at wide apertures in terms of enhancing the shallow DOF effect for central composition is a good topic for another thread.
Indeed it's. Wide open portrait in shallow DOF has least concern in corners.
Funny LR shows at F2.0, Canon is slightly sharper than Sigma in center that actually is what I prefer over corners, LOL
It doesn't. As I said, at f/2, LensRentals shows the Sigma 9% sharper in the center (915 lw/ph vs 840 lw/ph) and 40% sharper in the corners (545 lw/ph vs 390 lw/ph).
I have updated in my last post that you replied too quick. I looked at wrong low.
There's also the matter of vignetting -- the 35 / 2 IS vignettes a lot more at wide apertures than the Sigma 35 / 1.4, although that is not necessarily a bad thing, as long as it fades when stopped down to f/4 - f/5.6 (and it does).
http://www.dxomark.com/Lenses/Compare/Side-by-side/Canon-EF-35mm-F2-IS-USM-on-Canon-EOS-5D-Mark-III-versus-Sigma-35mm-F14-DG-HSM-A-Canon-on-Canon-EOS-5D-Mark-III___1086_795_1056_795
DXO lab test shows 35/2.0 IS @F2.0 has -1.8EV vegnetting vs Sigma 35 A @F1.4 has -2EV, so Canon has less at respective wide open. True Canon has more if both at F2.0.
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.
Sure.
That is the #1 my consideration to get 35/2.0 IS.
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 is 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 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 cross entire FL).
Is that so? According to LensRentals:
http://www.lensrentals.com/blog/2013/01/canon-24-70-f4-is-resolution-tests
The 24-70 / 2.8L IS II is ahead of the 24-70 / 4L IS at f/4 across the image circle, just as the Sigma 35 / 1.4 is ahead of the Canon 35 / 2 IS at f/2.
It seems Lensrentals may get a great copy of 24-70L/4.0 IS while DXO may get a great copy of 24-70L II in opposite as DXO shows 24-70L II at F2.8 beats 24-70L/4.0 IS @F4.0.
DXO 24-70L/2.8 II @F2.8 vs 24-70L/4.0 IS @F4.0
Sure, they are not exactly the same -- only a fool would think that the differential between the Sigma 35 / 1.4 and Canon 35 / 2 IS would be exactly the same as the differential between the 24-70 / 2.8L II and 24-70 / 4L IS.
In any case, those lenses were not even mentioned in this thread until you brought them up. and completely irrelevant to the discussion at hand. Perhaps in another thread when someone writes a review of the 24-70 / 2.8L II and/or 24-70 / 4L IS.
Just quoting an example that by picking up 35/2.0 IS you don't sacrifice optical quality if you don't have to shoot at F1.4 most times. Sigma 35 A advantages (except body build quality which I don't really care as I am not going to use it for 30 years) are really in two areas - F1.4 and sharper F2.0. Canon 35/2.0 IS advantages are also in two areas (that matter to me) - 4-stop 'IS' and much lighter/smaller body. I call them even and a person picks up at his/her priority.
