L series vs, L II series

What is the difference?? I'm looking at a 16 to 35mm

I am assuming your seeing the two versions of the 16-35. The second(II) is an upgrade from the first, not sure on the exact specs on what was improved...but usually sharpness, flare, design, and other things are improved on. If you have the money, go for the II!

I'd get the II. Here's a review: http://www.slrgear.com ….php/product/10​82/cat/all

Sharpness, especially into the corners at the wider end - is the biggest difference between the Mark I and II 16-35mm. A bigger filter size is also somewhat major (as these larger filters are quite a bit more expensive)

Another difference is flare. Version I flares like nuts.

It is usually better

In the case of the new Mark II L's (70-200 f/2.8L IS II, TS-E 45 Mark II) they add the new Nano coating.

nureality wrote in post #11368291
In the case of the new Mark II L's (70-200 f/2.8L IS II, TS-E 45 Mark II) they add the new Nano coating.

And weathersealing, for example the 24L (and 50L though technically a Mark I). Both 16-35mm versions are weathersealed, however.