Samyang makes these lenses and they get rebranded under names like Rokinon, Bower, and even Vivitar. While we have tagged this post with the term “Low Budget”, it’s still not a cheap lens, but relative to your other options for 135mm F2.0 it’s by far your cheapest option. If you need something cheaper and you shoot Canon or Sony, there are many old 135mm F2.8 lenses that can be had for around $100 on eBay and used on your Sony or Canon camera with an adapter.
For roughly $480 we are very impressed with the Nikon AF-S 85MM F1.8 G. On the Nikon D810, Nikon’s highest megapixel body, we prefer it to the much more expensive 1.4 G model (because of lateral chromatic aberration issues with the 1.4G). We also found the 1.8G to be slightly sharper than the 1.4 G model.
To keep life simple and to avoid compatibility issues down the road we prefer to avoid third party brands of lenses whenever possible. But for some reason the 50mm choices for both Nikon and Canon are surprisingly poor. While the Sigma 50mm Art lens is no Zeiss Otus lens (which costs about 5 times more), it’s an excellent lens and clearly better than the native offerings from Canon and Nikon.
This video shows Sigma’s 50mm Art lens in use for shooting fashion pictures. It provides a glimpse of what to expect from this lens. But remember, both Canon and Nikon’s cheap 50mm F1.8 lenses cost only a fraction of the price of Sigma’s lens are more than fine to start out with. Learn the art and the trade before worrying about having the best and most expensive of gear.