The N90 has a flash sync of 1/250th, it will meter with AIS lenses, it's heavier, fatter, sturdier and older then the N80. The N80 is lighter, thinner and newer. It has a pop up flash and a flash sync of 1/125th. It does not meter with the AIS lenses. The cost is close to the same with both models and usually less then a hundred bucks. The two camera's are very different to hold (ergonomics) due to the size and weight. I have a N80 and like it but I just use it as a snapper camera and take it hiking and cycling and such. It's nice and light and the replacement cost is very low.