PanF+ is not known as a film with very wide exposure or development latitude. That means it can be more difficult to achieve acceptable results by guesswork than with other films. If you want to continue using PanF+ it could be helpful to at least test for your own EI. If you give more exposure and less development you are always reducing contrast.
Originally Posted by Kevin Kehler
If it's the fine grain you like try Delta 100 or TMax 100. Perhaps start with the box speed and recommended development times. If you then want a little more shadow detail reduce the speed. If you want more contrast increase your developing time.