EchoLocation said:
This lens sounds great, but i'm just a little surprised that nobody thinks the price is high at all.
I don't think it's crazy expensive, but it definitely doesn't strike me as the bargain that many people make it out to be. What lenses are we comparing this with besides the Canon 1.2? Just a thought i'm having, I know the 50mm 1.4 Canon is old and poorly regarded but literally nobody is comparing these two lenses.
I had the old Sigma 50mm 1.4, and I LOVED it, the bokeh was awesome, and it was really sharp(I did have to return my first copy as it was very softttt.) But that lens was $400 new and worked fantastic for me for a couple years.
Is the new Sigma really twice as good as the old one?
Is the new Sigma really twice as good as the old one?
No. The new Sigma is more than twice as good as the old one. 240% better specifically.
If you're asking these kinds questions though I don't think you understand how important this Sigma lens is.
Sigma says it is positioning this lens to not even be remotely in competition with any other 50mm lens on the market. And all reviews have pointed to them being right. What that means is this 50mm lens makes all other non-zeiss competitors obsolete. It's like comparing a Mercedes AMG versus a snail in a race, it's just a different class.
The reason for this is that 50mm lenses have traditionally been of the double gauss (planar) design, which severely limits image quality at fast apertures. It's a very poor archaic design that results in around 4 times worse performance in every image clarity measurement. The reason for this is that to make a double gauss lens properly you would have to put elements inside of the mirror box to make the lens sharp. Because you can't put elements inside your mirror all 50mm lenses prior to 2014 for DSLRs have been soft. The only upside to the double gauss design is a slightly more compact lens. There is literally no planar lens that performs even passably well wide open. The Zeiss Otus was the first retrofocal normal lens for full frame cameras and it showed there was a night and day difference compared to the double gauss design. The Sigma 50mm ART is the second.
Planar lenses have extremely poor performance wide open, lets use the lens rentals 50mm comparison as an example (
http://www.lensrentals.com/blog/2012/01/the-great-50mm-shootout), which tested 23 planar normal lenses. At f/1.4 planar lenses achieved scores in the 300s and 400s in that test for average MTF50 resolution. For comparison the Zeiss Otus delivers average resolution of 800. That's just under 5 times more spacial resolution than the lens it supersedes, the Zeiss 1.4 Planar, @ f/1.4. (remember we have to square linear resolution data to get normal resolution)
If you look at other points of comparison you can see that planar 50mm lenses scored poorly in haziness/glowiness and purple fringing, and often scored poorly in chromatic aberration, usually by a factor of 3-5.
It doesn't take a genius to see why this is important. We just went from having the sharpest 50mm prime being literally the bottom of the barrel, delivering image quality so poor camera phones from several years ago beat them when they are wide open to having a lens that is one of the sharpest primes money can buy. It's like comparing unarmed chimpanzees with nuclear weapons. The lens doubles or triples everything we know about 50mm lenses at the least. This is the greatest improvement in image quality that has ever happened in DSLR photography.
So to get the single greatest improvement in a class of lenses for only $949 is the bargain of the century. Canon or Nikon would have charged you $3000 and still wouldn't be able to keep these in stock.
Double Gauss lens f/1.4 (Zeiss 1.4 Planar)
Retrofocal Lens f/1.4 (Sigma, 35mm 1.4 - remember the 50mm 1.4 ART is slightly better than this, but this makes for a clear comparison):
