Your coreect charts, back on track, i have a 240 and a 170, not really much in it, stabba is right, if lamping from a window the drag from the 240 can be a real issue, and the larger lens was also a pain last night when i tried to take a pee and managed to spray the thing I do feel like Jimmy Saville at times as i hang the lamp around my neck, but with my eyes the 240 is generally brought into play........