Review on Opteka 6.5mm f/3.5 Professional Ultra Wide Angle Aspherical Fisheye Lens for Canon EF-Mount Cameras: EOS 90D, 80D, 77D, 70D, 60D, 50D, 7D, Rebel T8i, T7i, T7s, T6s, T6i, T6, T5i, T5, T4i, T3i, T3, T2i and SL3 by Patrick Arnautov

I have a canon t6i and normally like to use and shoot with 10-20mm lenses but decided to go with something wider. I decided to roll the $160 dice and give this lens a try. I figured I really wouldn't use it much, so didn't want to spend a lot of money. I've had it for about a month now and not only do I love it, I use it all the time. Let me call it the #1 for $160, it's a great lens and my only regret is not buying it sooner. #2 It's fully manual, so you'll have to focus it manually, but because it's so wide, you'll find that you're using two focus points: 1ft for anything 1-5ft from you, or infinity for anything other. Almost everything is in focus with this approach, so you really don't have to fiddle with focus much, and my concerns about the lack of autofocus didn't turn out to be an issue. #3 It has a manual iris so your camera's Auto, Program or TV mode will not work. Set the camera to AV again and adjust the aperture with the ring and everything works very simply and well. And of course you can shoot in manual mode #4, that's fisheye, so if you get a kink in the shot. When shooting landscapes, if you hold your camera parallel to the horizon, you won't notice and you'll get amazing wide-angle shots. If you point the camera up or down, or get close to walls, you'll see a curve, but it's actually pretty cool. I've included some photos where I held the camera horizontally and tilted it for a curved effect so you can see for yourself. #5 The optical quality is ok. It's certainly not a $5,000 lens, but the image quality is as good as any lens I've owned that's paid $1,500 or less for. #6 Construction, aperture and focus rings are solid. The lens cap is a little tricky to figure out, but once you do it slips on and off easily and stays securely in place. I carry my camera in a belt holster so I worry about losing lens caps. This one holds up well.