Ilford HP5 pushed to 1600 and developed in HC-110 dilution B (1+31) for 11 min.
Ilford Delta 400 pushed to 1600 and developed in HC-110 dilution B (1+31) for 13,5 min.
I have been using mostly Ilford HP5 which I think is very versatile and reliable in all conditions. Its good film under bright light but also manages to capture nice shadow details. HP5 also gives quite nice tones even when pushed 2 stops (ASA 1600). Only minus side when pushing it, is those dynamics in darker areas.
I use much rarely Ilford Delta 400 because in my experience it’s more suitable for some specific lighting conditions. Apparently the weather when taking these images was good for Delta because it was cloudy and light was soft. My biggest trouble with Delta 400 has been overexposed negatives when shooting under bright sunlight. But in softer light like in these images Delta 400 gives very nice tones and sharp images.
Conclusion: There is no big difference between HP5 and Delta 400 when it comes to grain, although I was expecting Delta having less grain because it is more modern T-grain film. More noticable difference can be found in contrast and shadow areas. Delta gives little bit less contrast and more shadow detail than HP5. Overall both films in medium format are very usable even when pushed 2 stops, at least grain or contrast should not be the issue for normal use.
Images were taken with Mamiya 6 and Mamiya G 75mm 3.5 and scanned with Epson V800. Only edit I made was little sharpening.
100 % crop:
HP5, 100 % crop
Delta 400, 100 % crop