Hi.
I have just used a Haida polarize filter for the first time on my 300mm lens, I could not get a decent sharpness, initially suspected the lens had developed a fault, so checked it out, good focus without filter, poor with?
Noticed this straightaway on the 300mm, but not on my Sigma 17-50 (f/2.8)when I used it recently, so also checked this lens too on same target, spot on focus on or off. The gearing is not so good on the sigma so where critical focus is needed I use manual focus, zoomed 100%. Struggled to tell the difference, filter on or off, in fact I would say filter on was sharper.
Not being an exact approach I've put this down to the user, but the point is, no determinable difference with the 17-50, big difference with 300mm. So much so I could see the error through the viewfinder which is no mean feat these days.
Although reasonably priced, these filters get a good right up, same glass as B+W........ I will keep it, as due to the light loss on the 300mm I always intended to use it mainly on the 17-50, and cannot fault it on this lens.
Any thoughts?
Last edited by PaulR100; 11-18-2014 at 05:03 AM.