I know there's quite a few threads dotted around online aimed at this very question, however I wanted to run this past anyone with studio and ND filters experience. I've researched it quite alot, and was pretty much set on the 50mm. I have the D5000 so I've been coming to terms with the idea of manual focussing, which although I'm slightly disappointing about, part of me is happy to start learning now so that maybe one day I'll be able to do it properly. I bought myself a studio kit of 3 x 300w/s strobes, soft boxes backdrop etc, at Christmas which I've enjoyed playing with but found them too powerful for my small makeshift studio, and spend most of my time trying to re-arrange things to move the lights back further, as I'm already at f22 and the lights on their lowest power. So as a result I've been thinking of getting a Neutral Density filter, (Hoya seems to be highly regarded). But if I get the 50mm I wondered if manual focusing with the filter on may be impossible if its too dark? Or do they only dampen the light and its still easy to focus on something?? Or bite the bullet and get the 35mm which seems ok apart from pretty bad chromatic aberrations?