You never "need" a zoom lens. I know photographers who never use them. I know others who use only zooms. Zoom lenses are a convenience, which let you have multiple focal lengths in one lens, and shoot wide angle, normal, and telephoto, with only one lens. Walking around with your camera, and an 18-300mm zoom is easier on you than is carrying your camera, and a half dozen Prime (single focal length) lenses. However, zooms will always produce less sharp images than will Prime lenses. If you want the sharpest possible images, use Prime lenses, and put up with the hassles of carrying multiple lenses. Buying a zoom with your camera lets you become accustomed to shooting various focal length images, and decide which you like best. Zooms are fine for small print (3x5", 4x6", 5x7") snapshots for your family photo album. For larger art prints for photo contests, sales as magazine covers, posters, etc, use Prime lenses. You can use zooms for professional shots, and many do, but the same shot done with a comparable Prime lens will always be a bit better.