In article <4chpit$l0c@news3.cts.com>, pcolla@cts.com says...
>Nikkor 300mm f/4 AF question: Can anyone comment on using a front >filter (to protect from ocean spray) with this lens -- does it cause >vignetting, and if so, at what aperatures is the vignetting worst?

If you use the right size filter (no step-down ring), there will be
no vignette caused by the filter (this can be a problem with wide-
angle lenses and thick-rimmed filters, but not with teles). BTW,
Hoya is an excellent, reasonably priced filter brand.
Hope This Helps