What's the difference between Kodak Tri-X 400 and Kodak Tri-X 400 Pan?
I can't seem to find the difference anywhere, are they simply the same just re-branded?
There is none, except the labelling. "Pan" is short for "panchromatic" which means that it can record visible light all the way from blue down to red. Amazing, isn't it? These days, it's the films that don't record the whole visible spectrum that get the special labels, like "ortho" (for "othochromatic" -- they don't record orangey yellows or reds, and can be worked with safely under fairly bright red darkroom lighting). There was even a time when ortho film was special new technology -- the earliest films only recorded blue light, which is why mid-nineteenth century landscapes have white skies.
I would expect that Pan X (or Panchromatic X), if it is still available, would still have "pan" in the name, since X isn't a recognizable brand name.
The second hit is about Pro Tri-X 400, and that says:
At a quick glance, I notice that the timings in development charts are slightly different. So, it is a slightly different film.