I don't need a new lens. At least that's what I say to my better half. But my Amazon wish list is growing continuously. There are some events in the near future where I would like to have a fast 85mm lens for. From a price perspective there are just two options: the Canon EF 85mm f/1.8 USM and the Sigma 85mm F1,4 EX DG HSM. The Canon 85L 1.2 is out. I simple can't justify the expense.
Build Quality
Let's start with the Canon lens here. It ships in a small box which includes the lens and the manual. If you're used to Canon L lenses the Canon EF 85mm feels kind of cheap. It's made of plastic and is very light. The focus ring moves smoothly to the left and the right but does also rattles a little bit to the front and the back. But it is way better than the Canon EF 50mm 1.4! While the lens might be solid it does not feel like this. It is very likely that you have this impression only if you have the Sigma 85mm 1.4 on the same desk. This lens is a rock and you can take this literally. The Canon 85mm weights 400g, the Sigma 719g. It's heavy. But it's all about the glass. While the Canon has a 58mm font lens, the Sigma has 77mm. That mean you can use all of your filters which you bought for other Canon L lenses. That's great! The focus ring of the Sigma is very smooth and does not move in directions you don't expect. It's made of plastic too but feels a lot better. Out of the box you get a very nice lens hood as well as a padded box for your lens. It also comes with an extension tube for the lens hood which you can use with APS-C cameras.
Specification
I already covered the size of the filter thread and the weight of both lenses. Another difference is the smallest aperture. Sigma features a minimum aperture of f/16 while you can close the Canon down to f/22. Both have a minimum focus distance of 85 cm. While the Canon lens has eight aperture blades, the Sigma lens has nine of them.
Price
Those two lenses are prices at different levels. While the Canon EF 85 is kind of cheap, the Sigma has a significant price tag. It is nearly three times the price of the Canon. This time it's like buying vegetables. If you want to get more glass you have to pay for it.
Image Quality / Handling
This one is tricky. There is not much difference in the test images I took. From my perspective the Sigma lens produces warmer images. It seems to be lightly brighter using the same aperture. I already noticed that in my comparison of the Canon EF 50mm 1.4 and the Sigma 50mm 1.4. I like this very much. The bokeh is very nice on both lenses. From what I read in other reviews I expected a bigger difference. Especially at f/1.8 they are similar but you can open the Sigma all the way up to f/1.4.
I bought a Sigma 85mm F1,4 last year but was not satisfied with the keepers I've got. This times it is a totally different story. I shoot some portrait images yesterday and I was really amazed how many of them where sharp. I had to delete just very few images. The focus speed pretty much okay too. The Canon EF 85mm is a bit faster here.
Verdict
I'll keep the Sigma 85mm F1,4 EX DG HSM. It just feels right and does not look like a toy. The focus of this lens is exactly at the right spot both on my 5DII and the 5DIII. I'm sure the Canon EF 85mm f/1.8 USM performs as well but I can't use my existing filters with it and I don't want to buy new ones just for this lens. Finally I like the warmer images the Sigma lens produces.