Widest lens?

How wide can you go on the mft? Lens suggestions?

As wide as your pocket can afford

For me the question is how wide before the distortion becomes intolerable… avoiding the fisheye look.

I'm wondering if the Tokina 11-16mm with Metabones SpeedBoost is about as good as one gets depending on what one tolerates. That would be about 22mm FF equivalent on the Pocket at the widest.

Otherwise one might need a 7.5mm MFT lens to be about 22mm FF equivalent on the Pocket.

I thought I'd link to this thread
viewtopic.php?f=2&t=14394

and specifically Kowa 6mm f/1.8 C-Mount:
which would be about 17mm on Pocket

and his examples

In terms of wide availability and rectilinear behaviour, Sigma 8-16 in Nikon mount on a SpeedBooster. I can't guarantee vignette or edge sharpness as I've not used it myself. Gives about 16mm FF equivalent.