Quote Originally Posted by bohica
my main reason for asking the question was i have 2 lenses, a 110 and 80, both 2.8, and it just seems odd that the mfr would make 2 lenses so close in focal length with the same max opening unless possibley the 80 let in a little more light.
This is just a guess, but I think the reason is a combination of technical pursuits (improving the product, trying new solutions, etc - I am far from a lens design guru, but from what I understand,there are design differences, lenses being optimized for different applications, etc.) and.. well, marketing. There seem to be fewer "buy what I need" types out there than victims of "oh! I need that!" (myself often in that second group, despite my better judgement )