portrait lens

[mastertrinity]

i am after a new lens for and i have noticed the tamron 17-50mm and sony 16-80mm but i really want the sony and realised that its not a constant aperture, do i really need the constant f2.8 aperture of the tamron or can i suffice with the f3.5-4.5 of the sony?

 

[POAH]

no you don't need a constant aperture. not all portraits are shot with tiny DOF, most of my studio work is shot @ f8. outside you might want to blur the background and a lens of over 70mm f2.8 or faster would be nice.

 

[mastertrinity]

so really i only need to find the best in image quality, would the sigma 28-70mm be any good.

 

[HybridUK]

The Tamron 17-50mm 2.8 is a peach of a lens. You'll find a lot of people on these forums with one. The constant aperture is very handy through all of the range and great in low light. I know this probably doesn't quite answer your question about using it as a portrait lens but at the 50mm end it might do the job well.