So Which One Do You Recommend?
Let us postulate a client with an APS-C sensor camera who wants one lens. Only one lens. Has the body, wants to take pictures, hopes to take good ones.
Lots of the manufacturers of the digital bodies supply short-zoom lenses to start people out - and most times it works well. People get a chance to see the world from a moderate wide angle to a mild telephoto, and can shoot in moderate light levels. The results contain the distortions that zoom lenses are prone to but as these are far less that ever they were, and probably far less that the new user is used to...all is well.
But here is our client with his APS-C body and I want him to have as good a view of the world as possible. In this case I would screw my courage to the sticking point and reach for the.........Sigma Art series lenses. Specifically the 30mm f:1.4 DC - for a number of reasons:
1. Prime lens. Minimal barrel or pincushion distortion. Minimal chromatic aberration.
2. 30mm translates to the same angle of view of a 45mm lens on a full-frame camera. Very close to the classic 'standard ' length lens.
3. f;1.4 means low-light capability and soft focus in the background when desired.
4. Built like an artillery shell - very good barrel construction. Long-lasting lens.
5. Two-year warranty with a reliable firm.
6. Made in Japan by a dedicated factory.
Equipped with this, a couple of filters, and a memory card, the client can go out and take pictures that will be sharp, well exposed, and colourful. Encouraged by this, they can come back and buy more Sigma lenses with different capabilities......but they need to start out well.
They also probably need to put down their iPhone and stop looking at other people's opinions on web sites - and go out to take their own pictures.