opteka 6.5mm fisheye canon mount

canon mount fish eye lens. will post pics soon,mint shape used a few times.metal mount solid lens.$150 Canadian. or trade towards m43 stuff,will ship any where at your expense

I found the box for this lens. Removable hood and it's a limited edition lens. Not sure what that means. Maybe because it's a 6.5mm instead of reg 8mm in fish eye.

It's the same exact lens as the Samyang/Rokinon 8mm 3.5, opteka and Vivitar just stated different focal lengths for some reason. But they're all 8mm(s) made by Samyang in Korea. Focal length does actually change while focusing, this happenes on every lens. I think that's how they could get away stating different ones.

maverick75 wrote in post #17774703
It's the same exact lens as the Samyang/Rokinon 8mm 3.5, opteka and Vivitar just stated different focal lengths for some reason. But they're all 8mm(s) made by Samyang in Korea. Focal length does actually change while focusing, this happenes on every lens. I think that's how they could get away stating different ones.

The focal length of a fisheye lens is not straightforward to define, because it varies over the image. In the case of this lens, I think the FL is effectively 8mm on a normal crop camera... but there is a bit more image available beyond the crop frame, and it can be accessed when the lens is mounted on an APS-H or FF camera. When that extra image is included, the FL could be deemed to be 6.5 mm.

Thanx for the great info. Still not sure why this lens is a limited edition though. May be there removable hood. Not sure why u would want to take it off though. It protects the bulging lens

genesimmons wrote in post #17775899
Thanx for the great info. Still not sure why this lens is a limited edition though. May be there removable hood. Not sure why u would want to take it off though. It protects the bulging lens

The older version had a fixed hood. But some people were using it on APS-H and FF cameras, and then the hood blocks some of the image. These folks were cutting the hood off to get more coverage. The lens won't fill the full frame, but there is more image with the hood off. With the removable hood that problem is solved - no cutting needed. It created new problems, though. The removable hood rotates easily and can then interfere with the image... and the hood is a bit hard to get on and off. Solution: cement the removable hood in place.