Originally posted by FrumPilot I really like the Nikon lineup and thinking to but the new D500 despite the fact that it's not FF, because of the superior and accurate focus and iso capabilities.
Nikon D500 AF isn't more accurate than another full frame system, the D500 is designed for dynamic shooting (>10 frames/s) for people who can't afford the D5 who still need speed of af tracking in motion subject and can trade-off on sensor iso noise.
Each camera is tailored to a major type of use:
D5 and 1Dx = sport shooting, otherwise it is not cost/size effective at all to use a D5 to make portraits in a studio.
5DIII,5Ds, D810,D750, K1 = tailored to be ff sensors (good IQ) for studio, landscape, weddings, slow moving subjects , not tailored for sports (although they can also be use, they won't perform very well for sport photography)
K3, 7DII, D500 = tailored for sports for folks doing birds in flight etc who can't afford their big brothers
D7200, 80D, and similar cameras (could be KS2 or K70? ), slow and apsc => tailored to be affordable
Mirrorless apsc / ff = studio, travel, street, landscape, family and friends
K1 and D500 can't be more different, they are designed to perform for different kind of photography. And regarding AF accuracy for static subject, you may not be able to tell the difference between the two cameras and even the slowest camera may be optimized to be the most accurate.
Regarding a few lenses that you already have (canon , pentax , whatever) , they may not fit well with the new camera and you anyway may end-up having to trade your lenses as well.
So, you first have to decide what type of camera you need (Big fast expensive, small fast cheaper, budget dslr, or pocketable mirrorless).
Then you have to compare offering of each brand for the type of camera you want, including the choice of lenses you can mount on the camera.