This lens will cover the APS and Super35mm sensors.
It was designed for a 1 inch TV tube, but covers a 6/3 inch sensor!
It will cover the BMPCC, the 4k and 6 k, with different angles of view, or as some say, crop factors of 1, 3/4 and 1/2 respectively. But still 75mm.
The group making the lens is owned by Asahi. The name is Pentax or Ricoh, nowadays, but was also Cosmicar. The formula did not change. The PENTAX has 6 iris leaves.
The focal length will ensure space between your suibject and the camera, allowing some intimacy, but also a little distance. This focal length is more necessary for the APS sensor, as a 50mm will do well for m4/3. For the smaller sensor the distance is enough for a very flat perspective, and more objectivity.
A point to remember about c mount lenses is that fungus filaments seem to be rare, except on the very large zooms.
The photo of the young Rainbow Lorikeet and parent was taken on a Nikon 1 1 inch sensor at 1/100th sec. The background was very bright and it shows the flare resistance of the coating on the lens.
https://www.youtube.com/watch?v=ABmkfzrwrOQ
Samples from other sources, not me:
http://forum.mflenses.com/cosmicar-75mm-f1-4-wide-open-cmount-sony-a7r-aps-c-t77814.html
https://www.youtube.com/watch?v=64tAaZQQtZs
https://www.youtube.com/watch?v=76Zp2I-UkYU
Shooting videos uses less of the APS sensor, so hard vignetting is removed even at very tiny aperture F16.
This is not a small, fiddly lens. It is all metal and glass. The set screws can be replaced with standoff screws for easier operation, if required.
It is a sharp lens with high contrast.
Consider joining us at https://www.facebook.com/groups/cmountondigital ?