In South Africa, Sigma have been a popular option for photographers when looking for a Nikon or Canon lens alternative. The Tamron brand was founded in 1950, with Sigma following in 1961. I remember Tamron from the 80’s when I first started in photography. Today Tamron is getting more exposure through their new SA Distributor. I would highly recommend that any photographer considering a ‘generic’ lens, certainly do some research into Tamron as alternative.
Studio22 recommends www.dpreview.com for a fair review of all photographic products.
Tamron receive plenty of interest in their all-rounder, the 18-270mm lens, for its remarkable range. At Studio22 we have a nickname for a single lens with such wide zoom range, we call it a ‘holiday lens’. You will only need one lens if you go on holiday and the 18-270mm certainly gives any holiday maker the spectacular range, from a wide, wide-angle right through to a long telephoto all-in-one. No need to risk dust or moisture each time you change lenses. No time wasted changing lenses when you want to capture that special shot. No need to carry three lenses to every corner of the globe, Tamron gives it to you all-in-one.
Multiple awards: http://www.tamron.com/lenses/prod/18270_vc.asp
Tamron home page: http://www.tamron.com/lenses/default-photo.asp