I did a brief report on the Mitakon Zhongyi Speedmaster 50 mm f/0.95 lens a while back. I noted that the sensor in the camera I used, the Sony a7RII, couldn’t make use of all the light the lens gathered. In one of the DPR fora, a question arose as to whether or not that affected the out-of-focus (OOF) point spread functions (PSFs) of the lens.
I ran my LED flashlight test this morning:
The PSFs don’t look like evenly illuminated disks at all; they are brighter in the center and taper off near the periphery, like those of an apodized lens. Ignore the small sudden changes in brightness vertically; that’s due to the pulse-width-modulated flashlight.
Very interesting, at least to me. Maybe some optics expert can explain why the microlenses and the lens interact this way. Brandon?
[…] I published a post showing unusual behavior of out of focus point spread functions (OOF PSFs) using the Mitakon […]