Awesome quality lens, optics are great, and the f/2.8 really helps in darker situations. The only problems I find are that on DX or crop sensor cameras the fisheye effect seems to not be as effective and creates more of a vaguely distorted image. But when used with a FX, full frame or 35mm film camera the results are phenomenal. The lens has actually stayed on my 35mm film since I bought it.