I will be starting a project soon using T-Max 400, where I will have to compress a 13 stop range. I am thinking of using semi-stand with either divided HC-110 or one of the Pyro formulas.

I have never tried pyro, but from the posts I have read, Pyrocat-HC or Hypercat or 510 or Dixactol sound promising.

Would such a compression be possible with any of these using rotary processing, or would semi-stand be required?

Which developer and technique do you recommend for such a contrast range?