I have used 35 mm single lens reflex camera systems since about 1965 when I started out with a Honeywell Pentax Spotmatic, and a 50 mm f/1.4 lens. In 1966, I added to that a Spiratone 35 mm f/2.8? wide angle lens and a Sun Zoom 70-210 mm f/4.8? telephoto. Later I added a 400 mm f/6.3 preset lens.
In 1977 I moved to Canon F-1’s and ended up with a nice system of Canon prime lenses 17 mm f/4, 28 mm f/2.8, 50 mm f/3.5 macro, 85 mm f/1.8, 135 mm f/2.8, and 200 mm f/4 and three F-1 bodies. Late in the life of that system I added a Tamron 500 mm f/8 mirror lens which was not what I had hoped it might be.
After a brief flirtation with Canon EOS, I moved to Nikon in 1990 and have been shooting Nikon ever since. I had more lenses and bodies than I ended up knowing what to do with, going from 20 mm to 500 mm f/4. Over time, I owned six Nikon film bodies, five DSLR bodies (so far), 11 prime lenses (all but one a Nikkor), 9 Nikkor zoom lenses, and 5 Nikkor teleconverters! In 2003, I bought my first D100 digital SLR and have had two of those, a D200, and now shoot with two D7100 bodies.
Thinking back on this, I spent 12 years with the Pentax/Spiratone system, 12 years with the Canon FD system, and I’ve been with Nikon for 24 years.
I was somewhat happy with the 18-200 mm lens on the D200, but it didn’t make me happy on the D7100. I suspect that the 18-200 was perhaps the limiting factor for resolution on the D200, at least at some focal lengths! (click the image for a larger view)