Focal length and distortion in wide angle?

I realize that things like lens quality, the camera, etc. will have an impact but is there an approximate focal length when distortion becomes more of a factor in wide angle photography?

Focal length is only half the equation. The sensor/film size is the other. A 100mm lens will be 'wide angle' on a large enough format.

Fiend of View, or Angle of View, is more what you're asking about. As for it's 'impact', that depends solely on the subject. Also, the spatial relationship between the camera and the subject. As well as the planes of the subject, lens and sensor/film.

In short, there is no 'one' answer for your question, other than 'depends'.

Since I never had a wide angle DX lens, when I had a DX Nikon, I can only guess. But for your Nikon I would guess from 14mm and wider will have some distortion, depending on the shot as my buddy 480sparky just mentioned.

Technically, ALL lenses will produce perspective distortion. But as the FOV increases, the more it becomes obvious.

I did shoot a lot with my D7100 and Tokina 11-16. There are ways to minimize the distortion of shooting wide angle. First always shoot level, never point up or point down. The closer you are the worse the problem will be. There are ways to correct most of the distortion. I ended up buy a program just for this problem. Is DxO Viewpoint. This is a piece of software that I could not live without now. My wife recently went to New York and I had bought her a pocket camera for the Trip. It was the Nikon Coolpix S9900. Shooting on the streets in New York all the buildings seem to lean in over the street from both sides. This software fixes that problem and makes the final photo look so much better. Fixing the distortion only takes a few clicks.

I have moved up to the D750 and have a 14mm on the way for it if you need a Tokina 11-16 let me know.