Sigma EX 4.5mm f2.8 DC HSM Circular Fisheye for Canon EF-S wall adapter The DG-2 has 19mm threads

The DG-2 has 19mm threads

Requires a compatible filter holder (not included)

but the lens is sharp throughout its zoom range

And the viewfinder is huge

Sigma EX 4.5mm f2.8 DC HSM Circular Fisheye for Canon EF-S wall adapter The DG-2 has 19mm threadsThe Sigma EX 4. 5mm f2. 8 DC HSM is a circular fisheye lens for Canon EF mount cameras. While it's designed for EF S (crop format) cameras, it will also mount to EF mount full frame cameras. Worth noting that this is a fisheye lens so the image it produces is uncorrected for distortion and that, by design, the image does not fill the entire image area, even on EF S cameras. So don't get this lens if you're expecting a normal wide angle lens, because