I used to be very active in the days of SLR cameras and 35mm film (and slides). I knew a lot about F-stops, neutral-density filters, etc., etc. For a time, I even developed my own B&W film, if you can believe that!
Anyway, from the stand point of being in the photography business, I would ask if you are interested in specialty photography for advertising, or people's portraits, and that kind of thing, or, photo-journalism, which is a whole different thing, as you know.
Anyway, from a business standpoint, there's all the customary business expenses, competition, and efficiency factors to take into account. And the technology is light-years ahead of everything people used back in the 'old days'. I would say that, first, you identify the market-segment you want to be focusing on, and see what the income potential is (given your scope of projected operation). Advertising is a good source of income, but it is intensely competitive. Still, if you're good, it's pretty easy to excel because so many people who work in that 'arena' don't exhibit much imagination.
