if that is all the width you have you going to need a lot of room coming back from the photographers position. after goggling ada i see they recommend 1:12 (rise:run), so for every foot droop the ramp must extend 12 feet. it looks like you need to rise 6 feet so you need a 72 foot ramp.! you can gain length by zig zaging the route up the hill, even a long L or other rout if you have more room to the right of the fence. how ever you do it the total path length must be 72 feet long. If you increase the slope you run the risk of everyone slipping on the ramp from rain, dew, ice, mildew. If you put down plywood on the stairs get a jet pack and hit the ramp at full speed.
