Probably the Best 50mm Lens Ever Made: Canon RF 50mm f/1.2L Versus Sigma Art 50mm f/1.4 Versus EF 50mm f/1.2L

For many of us, a 50mm lens is the first "proper" lens that we ever bought. The kit lens can be great but there's nothing quite like a good wide aperture prime lens. Thanks to a rental company in the UK called Hire A Camera, I was able to test and compare what I think might be the best 50mm lens ever made. 

In this article and in the video linked above I compare three relatively popular 50mm prime lenses. For a long time, my personal favorite has been the Sigma 50mm f/1.4 Art lens. This is a lens I bought, own, and have used frequently. For the price, it offers incredible value for money due to its super sharp optics and quality bokeh. The trade-off with this lens is that it is rather large and heavy. This is especially true when you compare it to the older Canon EF 50mm f/1.2L. This lens is incredibly small and light compared to the sigma even with that wider aperture. I personally value having smaller and lighter equipment and for that reason, I really enjoyed shooting with this EF lens. Finally, there is the new Canon RF 50mm f/1.2L. This is the heaviest and largest of the three and with the most number of glass elements. The RF mount version is almost double the size and weight of the older EF lens which is quite a jump. Lining the lenses up next to each other clearly shows just how much of a difference there is between the three. 

Image Quality

Bokeh is the first thing I wanted to compare between these lenses. If you're shooting with a super wide aperture lens chances are you probably want to shoot wide open. In the gallery below, you'll be able to see three images from each lens. In all fairness the differences are minor, however, still noticeable. The Sigma art lens produced the most circular bokeh at the edges of the frame. Some people prefer images that don't produce a lot of that cat-eye type bokeh and if that's valuable to you then Sigma may be the best option. Both Canon lenses produce bokeh that is very similar in look and shape. The older EF mount lens was praised for having beautiful smooth looking bokeh and it's great to see that Canon has not sacrificed this feature in the updated RF mount lens. What's important to note is that although both Canon lenses have a wider aperture, in real-world use you won't notice a significant difference between f/1.2 and f/1.4 lenses

In the second comparison below I shot all three lenses wide open in a controlled environment. The EF mount lens wasn't known for being the sharpest lens at f/1.2 and it is considerably softer than the other two. Details are extremely muddy and have an almost out of focus look to them. The Sigma lens is a brilliant performer when it comes to detail and sharpness and even wide open it's able to produce beautiful sharp results. This is one of the reasons why the Art lens from Sigma gained so much popularity. It was one of the first few 50mm lenses at a relatively affordable price point that offered super sharp results. Then there is the new RF mount 50mm lens from Canon and this lens is simply incredible. Even at f/1.2, it produces some of the sharpest results I've ever seen. The detail and clarity it manages to retain is something that not many if any other f/1.2 lens can produce. Canon has really outdone themselves when it comes to how good this lens is for detail. Previously you would have had to stop all the way down to around f/5.6 just to get sharp results. This new RF lens is definitely one you can properly use wide open and produce detailed results.  

Finally, I wanted to see how these lenses performed in heavy backlit scenarios. In these situations, many lenses tend to lose a lot of contrast and heavy flaring can be distracting. The EF mount lens was the worst of the three and produced the most amount of flares and had some very visible loss in contrast. This can be a problem for some photographers, however, in my experience, many portrait photographers actually use these "flaws" in a creative way. The Sigma lens actually performed really well in this environment and not only did it retain contrast quite well but the flaring was better contained than the EF lens. The RF lens was once again the better of the three and produced the most detailed results with relatively minimal flaring. The RF lens also retained contrast better than the other two lenses. 

Autofocus

This is an area that I found a little tricky to compare for a couple of reasons. The main reason was the fact that I was comparing all three lenses on native mount cameras. The Sigma and the EF 50mm lenses were both only used on the Canon 5D Mark IV. To my knowledge lenses tend to work best on native mounts and for that reasons I opted not to adapt these lenses on to the Canon EOS R. Through the viewfinder the 5D Mark IV did struggle quite a bit when it came to low light scenarios. This was true regardless of which lens I tried. This is obviously more to do with the camera than the actual lenses. Having said that the Sigma did perform much better than the EF 50mm did through the viewfinder and this could be because the EF mount lens is much older. The RF lens never seemed to have any problems when it came to shooting in low light situations I rarely missed focus even when shooting wide open. On the Mark IV, both lenses did miss focus more frequently, however, once I switched to live view all three lenses performed in a very similar way. Both cameras use a very similar (if not the same) focusing system from the sensor and in live view, the shooting experience was pretty much identical with all three lenses. 

Real World Shooting Scenarios

Testing all three lenses with Anete who was modeling for us, I struggled to pick an overall winner. The reason is that each lens has its own respective advantages. The Canon EF 50mm was the worst when it came to sheer technical performance, however, I really enjoyed the small compact size. As mentioned above I personally value weight and size and for me, this was a great feature. The lens also produced images with tonnes of character. Yes, it is very soft wide open but for many portrait photographers, this may actually be useful. 

5D Mark IV and EF 50mm f/1.2L

The Sigma sat comfortably in-between both the Canon lenses both in terms of size and performance. Sure it's not an f/1.2 lens but honestly, the difference between apertures in real-world situations is minimal at best. Yes, the Canon lenses do produce slightly blurrier backgrounds but unless you have two images side by side, I doubt anyone will really be able to tell what it was shot on. The price point of this lens is what makes the biggest difference and I think the Sigma lens is the best value for money. It's still the cheapest of the three and it offers fantastic image quality. 

5D Mark IV and Sigma 50mm f/1.4 Art

Then there's the RF mount 50mm lens and this is without a doubt the best of the three. The details it's able to produce are simply incredible. I will go as far as to say that there is no lens like this on the market. More than likely it's probably better than any medium format lens on the market too around a similar focal length. Even wide open the clarity is simply stunning and this is something Canon continues to do really well. They may not produce the best cameras on the market but they produce some of the absolute best lenses. 

The main reason as to why I struggled to call this the overall winner was due to the price tag. From a technical standpoint, yes this is absolutely the best, however, it's not the best when it comes to value for money. With a price tag of over $2000, it's difficult to recommend when you have options like the Sigma art lens. If money isn't an issue for you and you demand the absolute best in quality then sure, this is without a doubt the best option on the market. As much as I love the kind of images this lens can produce, it;s not a lens I'll be buying anytime soon. I literally have no place for it in my workflow. I would however quite happily rent this lens and if you're based in the UK, I highly recommend Hire A Camera

Final Thoughts

Ultimately it comes down to what you value the most. If you're looking for the best 50mm lens on the market then the Canon RF 50mm f/1.2L is more than likely the one for you. There are no other lenses that can produce the kind of results that this lens can. Having said that, I still think the Canon EF mount lens has a place on the market for many portrait photographers. Its price point is much easier to swallow and it produces beautiful results with lots of character. Personally, I think I'll stick with the Sigma art lens for now because it's the most affordable of the three and still continues to offer fantastic image quality.

Please check out the full video and let me know what you think. 

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35 Comments

Previous comments
Usman Dawood's picture

Comparisons and results please.

Richard Sumilang's picture

Must be hard being a writer for fstoppers lol... Anyways, sadly the best 50mm is currently the one on my camera and no one here will ever be able to experience it.

Usman Dawood's picture

Properly love it :).

Is it a Leica, if so which one please and why do you consider it to be the best one?

The best lens is the one that's with you?

if i had 2k i wud spend it on the sigma 50mm and 35mm and still have $500 left to take all my hoes to the hotel room

Usman Dawood's picture

I’m guessing you’re a teenager.