All modes are useful, just a matter of habit for many photographers what they actually favour most. My EOS 1N is usually in Av mode when intervalometer back E1 is attached; else, the 1N is in Manual so that 2 spot meter readings can be averaged. In a sense, you do the same thing (albeit more intensively) with a spot meter (I know I do with my Sekonic L758 for pinhole work). You can have as much or as little automation you need or want just by altering the camera, or in some cases, the settings on the camera. It's great to get touchy-feely with the entirely manual work of a pinhole camera. I have serious reservations about the extreme level of automation in digi cameras that leaves many otherwise enthusiastic users disenfranchised and upset when results aren't what they expected (because, of course, the camera is doing everything for them...).