Review of the Sigma 50mm 1.4 Art lens - Is this my sharpest lens now?

I am lucky because I get to try out a lot of different camera gear. Sometimes I have companies offering to send me products to try and other times I may contact them to see if I can try a new backpack, tripod or lens. Well...about a year ago, I saw Sigma demonstrate a prototype of their upcoming 50mm 1.4 Art lens. I heard them comparing this lens to a Zeiss Otus lens (which costs $4000) and I was skeptical. Could Sigma really build a lens for $949 that could not only rival the Canon 50mm f/1.2 L series lens, but compare to the Zeiss Otus lens?

Last month I saw a notification that Sigma was finally shipping this lens, so I called the folks at Sigma and asked to borrow a lens to test. I got it last week, and the box has been sitting on my desk begging to be opened. I finally had a chance to open the box and put the lens to the test, and I was BLOWN AWAY at the results. 

I connected the lens to my Canon 5D Mark III, grabbed a small object to photograph and shot a couple of photos. Looking at the LCD on the back of the camera, I was stunned at the sharpness of the image. But then I thought "the Canon L series lens which costs $1500 must be just as sharp", so I put that lens on and shot the same small object. It wasn't nearly as sharp. I started thinking of all the reasons why my test would yield such different results, and then set up a test removing all those variables.

I set up my Gitzo tripod and connected the Canon 5D Mark III to my Acratech ball head. I set the camera in timer mode so that there would be no movement of the camera. All the photos taken here were shot at f/1.4 and ISO 100. I then shot photos of a little DJI camera that I had laying around.

Here is the result using autofocus with the Canon 50mm 1.2 lens (with the focal point on the lens of the DJI camera).

...and a close-up of that same shot.

Keeping the camera in the same position, I then switched lenses to the Sigma 50mm f/1.4 lens and used autofocus pointed at the same point of the object.

This is a close-up of the shot taken with the Sigma lens. Look at how much sharper the lens is!

I then wondered if it was the autofocus of the lenses, so I switched the camera to manual focus and took the same set of photos. This was the photo taken with manual focus using the Canon 50mm 1.2 lens.

Using Live View to zoom in and get as sharp as possible, this is the best that I could get using the Canon lens.

Then it was time to use manual focus with the Sigma lens.

The Sigma lens was tack sharp once again.

I decided to try once more with a different object. So I found this small flashlight on my desk and gave it a try again. I held a piece of paper to make sure I was not mixing anything up. This is the photo with the Canon lens and manual focus.

And the same shot with the Sigma lens. You can definitely see the difference in clarity. As a matter of fact, I was amazed at the clarity I was seeing in Live View mode. It was so apparent even while shooting.

Here is a close-up view using the Canon 50mm 1.2 lens.

And just for the fun of it, I tried the same test with the Canon 50mm 1.4 lens. Here is a close-up view using that lens.

Here is a close-up view using the Sigma 50mm lens.

After doing all these test shots, I started thinking that the results might be different at a lower aperture, so I repeated the same test (this time using the Canon 50mm f/1.2 lens, the much less expensive Canon 50mm f/1.4 lens and the Sigma 50mm f/1.4 lens) and shot the same photos at f/6.3. Here are the results of that test.

Results of shooting the Canon 50mm 1.2 lens at f/6.3. (Click on this photo to see the full res image)

Results of shooting the Canon 50mm 1.4 lens at f/6.3. (Click on this photo to see the full res image)

Results of shooting the Sigma 50mm 1.4 lens at f/6.3. (Click on this photo to see the full res image)

All three photos look good when zoomed out like this, but when you click and look at them at full resolution, you can definitely see a difference in the quality, even at a smaller aperture.

And here is a real-world photo I took of my dog Cooper, using the Sigma 50mm lens. As many of you know, shooting at f/1.4, you have to be dead-on with your focus as the depth of field is really narrow. For this shot, I focused on Coopers left eye.

I started this review with the clarity of the lens, because honestly, to me that is the most important feature to us photographers. Now I would like to tell you a couple more things about this lens.

The first thing I noticed when taking the lens out of the box, was the weight. At 28.7 oz, you can tell that this lens is packed with a lot of glass. It is taller and thinner and heavier than it's Canon counterpart. And the Sigma lens looks really great too, with a nice mix of polished and matt black finish. It feels solid in the hand and has a very smooth focus ring.

I did notice that the lens attached to the Canon camera with more force than I am used to. The Canon lens twists on very easily, while the Sigma lens took some more force to get it firmly connected. I don't know if this is due to the newness of the lens, but I don't remember other lenses, even when new, taking such force to attach.

The Sigma lens would also let me focus a little closer to the object than the Canon lens. Looking at the specs, it appears that the Sigma lens will focus 2" closer than the Canon 50mm f/1.2 lens.

I also noticed that the Sigma lens was slower than the Canon f/1.2 lens. With the camera set in Aperture Priority mode with the same ISO (100) and Aperture (f/1.4), you would assume that the shutter speed would be the same with both lenses, but that was not the case. Where the Canon lens would shoot at 1/80 sec, the Sigma lens was at 1/50 sec. This makes me wonder how these two lenses would compete in a dark environment. Remember, I shoot a lot of events where the lights are low.  Here is what I am thinking now: Even if the Sigma lens is 1/3 stop slower than the Canon, I can turn up the ISO on my camera. I would prefer to have a little higher ISO and a lot sharper photo. There is only one way to find out, and I can't wait to give this a try this weekend when I shoot my next event.

_________________________________________________________________________________

If you are interested in purchasing any camera equipment, please click here to go to B&H Photo, as I get a referral from them if you enter this way. I would really appreciate that.

_________________________________________________________________________________