What you are probably looking for, it is a circular fisheye lens for APS-C. Fisheye lenses are of two types: circular or diagonal. The circulars place the entire image circle in the sensor frame, while the diagonals are more traditional and project a circle large enough to cover the entire sensor and produce a rectangular image.
Keep in mind however that with a circular fisheye, you get a lot black on the frame with the image circle, which allows you to effectively reduce the resolution of your camera and with a more extreme circular fisheye, you may negotiate sharpness and chromatic aberration for a cover additional scene, compared to a diagonal.
Most circular fisheye lenses can do 180 ° on the short and long edges of the frame, but most diagonals cover only 180 ° on the diagonal (example: Samyang / Rokinon 8mm f / 3.5 diagonal diagonal for APS -C).
Here are some of the circular fisheyes to harvest:
- Sigma 4.5mm f / 2.8
- Lensbaby 5.8 f / 3.5
- Meike 6.5 f / 2 (sometimes renamed Opteka 6.5)
- Yasuhara / Madoka 180 7.3mm f / 4 (for mirror, Sony E / Fuji X)
And I even found one for MFT:
So, looking for hand-made lenses made in Asia could give some more candidates.