I have used Shanghai Pan GP3 100 in both 4x5 and 120 and for both the Dektol times are rather long. I have seen it recommended to do a 4:1 dilution for fourteen minutes, and I used to have success doing 3:1 at 8 and 10 minutes. That’s oddly long. 3:1 Dektol can develop some films in three and a half minutes and 7:1 usually takes only six and a half to seven minutes. Why does this (admittedly basic) film take so long?