Little basic information about me: I am Calvin, an enthusiastic part time photographer based in San Diego. It just happens that I have both 85L II and Sigma 85mm f1.4 at the moment. I know there has been many questions regarding which one to go for people who want to upgrade from 85mm f1.8 for a better portrait lens. I hope this post can contribute a little to those who are trying to make a decision at the moment.
I am not qualified to give any good suggestion on which lens to get, I can only list my observations and facts of the two lenses. In the end, only the person knows what is the best for him/her.
Introduction (Brief Comparison)
Let's start off with some basic facts about the two lens.
Canon (+) Shoot at F1.2, Canon's quality control and service, metal body, bokeh.
85L II shoots at F1.2 instead of F1.4; it is more likely to be calibrate to your Canon body unlike third party lenses; it has a metal body instead of Sigma's plastic body; it has a strong background dissolving power than Sigma. Canon has better overall customer service than Sigma. Personally I find it a big hassle to send anything back to Sigma for whatever reason.
Sigma (+) AF speed, price, sharpness(slightly better depends on copies), size/weight.
Sigma's AF speed isn't as fast as 135L/85 f1.8, but it is still significantly faster than 85L II; my Sigma seems to have a slightly better sharpness and contrast than my 85L II; Sigma weights 27 ounces while 85L II weights 36 ounces, and Sigma has a slimmer body that fits better in my camera bag.
(=) Both are fringing monster. It hasn't caused any problem to me so far because my clients don't pixel peep. Sigma's AF accuracy has been proven to be as good as Canon's to me. In fact Sigma's keeper rate is higher because of its faster AF. However,unfortunately, in the market there are bad copies which suffer from severe AF inconsistency. I bought my Sigma from a reputable photographer who'd been using it without a problem and luckily it works on my 5D perfectly.
Built Quality
Metal vs Plastic
These lenses aren't toy. They feel like a tank when I hold them in my hand. The Keg (85L II) is full metal, and it probably does contain more glasses than Sigma does, hence it weights a bit heavier than Sigma.
In contrast to Keg's fatness, Sigma has a slimmer body with smooth finish. Sigma's plastic doesn't feel cheap at all. In fact I think for durability, Sigma feels safer than Keg. Keg's back element touches the metal mount; it is so fragile that it could be easily damaged. Sigma seems to have a better protection for its back element.
Image Quality
Bokeh
Before I start, I would like to show three images of 85L at F1.2, 1.4 and Sigma at F1.4 which are under the exact identical exposure. Let's take a look at the bokeh quality instead of the subject. It is actually quite easy to distinguish 85L from Sigma.
1.
2.
3.
Image 1 is from 85L at F1.2, Image 2 is 85L II at F1.4, and Image 3 is Sigma at F1.4.
These images came straight out from the camera without any post-process.
They shot with the same camera setting with camera mounted on tripod.
All temperature and tint are manual adjusted.
Overall 85L has a smoother rendering across the entire image. This is where the creamy bokeh honor came from.
Let's look at background with more complexity, with more elements like tree branches and leaves.
85L wide open
And Sigma wide open as well
What we can see is that Sigma has a higher contrast and image tends to look a bit darker than the other from 85L II. Sigma at F1.4 actually has lower light transmission rate than 85L at F1.4 and also vignette kicks in and block out some light average intensity across the image.
For bokeh (background blur), 85L II renders a softer and more diffused bokeh than Sigma does (throughout the apertures; and this is what you paid the extra $1,000 for.)
Sharpness
85L II @1.2
85L II @1.4
Sigma @1.4
And again, we see image from Sigma appears to be darker and more contrasty.
Now let's look at 100% crop and pixel peep
85L II @1.2
85L II @1.4
Sigma @1.4
Surprisingly, the Sigma turns out to be a bit sharper than 85L II. I took multiple shots with each lens and picked out the best one. This is why the model looks little sleepy and annoyed in the pictures at the very end.
However, we can see that the sharpness isn't a mile away from each other, it should not be a deciding factor between these two lenses. Both lenses perform very well on sharpness. Sigma has a higher contrast therefore it seems to be a bit sharper.
Conclusion
So the question comes down to "which one is better for me?". Advantages with Sigma are the AF speed and price, while 85L II has extra 1/2 stop of light in theory(however, as many had pointed out for me, in reality it's 1/3) and softer bokeh rendering. Does 85L II's 1/3 stop of light and bokeh rendering worth the extra $1000 and the loss of AF speed? Does it worth the time for playing the lottery with Sigma for the extra $1000 saving?
I don't have the statistics on how often do people get a bad copy from Sigma.
Both lenses are magnificent crafts of glasses.
People who can afford Canon, they will go for 85L II and add an extra 85mm f1.8 for AF speed. People who can't afford Canon they will go for Sigma 85.But then some people who can afford Canon's 85L II would still ask does it justify the $1000 extra spending for better bokeh rendering. I think it does, because the moment we purchased our first DLSR, we were determined to go after the best image quality possible. For me I can't justify it because I can't afford it, I need to use my money for investment in other focal lengths, otherwise I would keep 85L II in my lens inventory.
However, some believe Sigma 85mm F1.4 is actually a better lens than the 85L II is (Refer to http://hofferphotography.com/2010/11/16/my-sigma-85-f1-4-vs-canon-85l-review/)
"Writing this next sentence is like disowning a child…. The Sigma 85 1.4 is a better lens than the Canon 85L. " said Tony Hoffer
I know many people pass on Sigma because of their AF inconsistency due to miscalibration to Canon's bodies. Most people aren't willing to spend their time to play the lottery with Sigma. I am proud to say I am one of the lucky owners of Sigma. Well for those with MFA on their pro-bodies, this issue shouldn't be too prevalent .
Followings are some shots done by Sigma
Anyways, either way can't go wrong.
And of course,last but not least, most importantly is to go out and shoot. It's the photographer who makes the image.
