August 26, 200719 yr Hello Which port should I need to use a 17 55 Nikkor with my D80 in a sea and sea housing . I own the sx extension ring , the 40 mm ring too , and the optical dome , the 40 mm with the optical dome seems to short for this long lense. Thank for your advice. Dominique
August 26, 200719 yr Hi Dominique, The 17-55 is not listed in Sea&Sea charts, which I link below: https://camerasunderwater.co.uk/slr/seaandsea/N-lens.html But they do list the 17-35 and they are almost the same size. If I had to guess I would start with a port combination that works on the 17-35 and see if it works. If you think the dome+ the 40 ring is too short you can stack the 40 and the SX rings.