Hi, I am considering to buy a Sigma 20mm F1.8 EX DG ASPHERICAL RF wide angle lens for my F75 film SLR camera. I just want a true wide and sharp lens at low price. If I get this one than it would be my first third party lens over my 3 previous Nikkors. I am unable to find a wide angle lens in Nikkor series as my my budget is too low. I just want your suggestions for choosing the right wide angle lens for the landscapes, cityscapes and nature shots with sharp infinity focus ability. I already have a 28-80 f/3.3-5.6 G Nikkor, buytt this fails at infinity and I just puted a thread about this lens also last night. I am also not certain about the performance of third party lenses on nikon cameras, as I nevered owned any third party lens.