Hi Please help me understand the difference between these developers, as their datasheets really doesn't shed any light on it (and I am not chemical engineer or expert )- I've used TMax developer, XTol and currently HC-110 and I find it difficult to find any huge differences in these. I can push Acros to 400 with HC-110 easily, and with good results, even though the datasheet doesn't say so for that developer for example. So what gives? KODAK PROFESSIONAL HC-110 Developer HC-110 Developer is a highly concentrated liquid developer. It is intended for use with a variety of black-and-white films, some graphic-arts films, and some glass plates. It can be used for replenished and non-replenished systems. Use KODAK PROFESSIONAL HC-110 Developer Replenisher to replenish. http://www.kodak.com/global/en/professional/support/techPubs/j24/j24.pdf KODAK PROFESSIONAL XTOL Developer XTOL Developer is a two-part powder developer for processing Kodak and other manufacturers’ normally exposed, pushed, or pulled black-and-white films. It offers full emulsion speed and easy mixing, and can be used as both a developer and a replenisher in a variety of equipment, from small tanks (8 to 64 fluidounces), trays, or rotary tubes to high-volume processors. http://www.kodak.com/global/en/professional/support/techPubs/j109/j109.pdf KODAK PROFESSIONAL T-MAX Developers T-MAX Developer is a moderately active, liquid black-and-white film developer that offers enhanced shadow detail in normally processed and push-processed films. http://www.kodak.com/global/en/professional/support/techPubs/j86/j86.pdf KODAK PROFESSIONAL D-76 Developer D-76 Developer provides full emulsion speed and excellent shadow detail with normal contrast, and produces fine grain with a variety of continuous-tone black-and-white films. For greater sharpness, but with a slight increase in graininess, you can use a 1:1 dilution of this developer. It yields a long density range, and its development latitude allows push processing with relatively low fog. http://www.kodak.com/global/en/professional/support/techPubs/j78/j78.pdf I'm none the wiser, but HC-110 works very nicely with most films I've tried so far (Acros, Neopan 400, Roillei IR400). Why are there so many different types here?