[Leica] wide-angle filter/hood question

[Guy Bennett <gbennett@club-internet.fr>]

lugnuts,

put down that flame thrower, i'm not talking about uv filters... shooting
yesterday in the père lachaise cemetary, i wanted to get a sweeping,
cemetary-scape type shot over the tops of the tombs, reaching to the trees
in the distance and including a stretch of sky. as i'm shooting b & w, and
didn't want the bright blue sky to turn white, i put a dark yellow filter
on my elmarit m 24 then went to put the lens hood back on - it wouldn't
fit. well, it did slide back onto the lens, but wouldn't 'click' into place
as the filter (b + w 023) was now blocking the little indent that permits
the filter to 'lock' onto the lens. i decided to remove the filter and
recompose my shot, including as little sky as possible, as i was afraid
that i would otherwise get some vignetting. now perhaps this was a
non-issue, as i wasn't shooting wide-open (i must've been at 5.6 or even
8), but i didn't want to take a chance. now that i've set the scene, here's
my question: to what extent will the filter, either alone or, in this case,
with a lens hood that won't fit all the way on (unlike the summicron m 35
asph whose hood fits over the filter) cause vignetting on a wide-angle
lens, and will this only happen when shooting wide-open? thanks for any
answers/suggetions you might have.

guy