One of the many things I miss from the old SkatePerception days were the threads dedicated to fisheye comparisons. I really wish that something like that existed today, so here I am attempting to get something going.
I've been filming with a VX1MK1 for way too long, and recently picked up an HMC150 because the local shop wanted an HD edit. I bought the vx_fisheye_sales (VXFS) MK1 adapter ($165 for a 75" to 72" step down ring, incredible) and I was curious to see how the two compared after the HMC was cropped and scaled:

Surprised to see that the HMC is a tad bit wider.
Hoping others share a similar interest, and can provide some useful comparisons. I will also try to dig up an old comparison I did years back for a GL1 that was a raynox->modded raynox->MK1 intermediate. Not really useful for today's standards, but still interesting.