nortoda1 13 Posted April 12, 2011 What extension should I use with a 10-17 Tok and Kenko 1.4x TC when using the Sea and Sea glass dome? I have the SX extension for use without the TC, do I need the extenion ring 22 or 40? cheers Darragh Share this post Link to post Share on other sites
jcclink 8 Posted April 12, 2011 Measure the height/thickness of the TC, which I recall is about 18-20mm. That's the size of extension ring you need. So given your options I'd suggest the 22mm. Share this post Link to post Share on other sites
Dupsbear 1 Posted April 12, 2011 Hi Darragh, Just because a lens will fit behind a dome port does not mean you are going to get quality images. This fact the reason I designed and build the Bare Dome Ports which are optimized for the Tokina 10-17 with or without a Kenko 1.4x teleconverter. We did lots of math before designing the dome curvature and size to make sure the nodal point of the lens and dome give the best images. Putting a lens combination behind a dome without doing the math might mean that you will have blurred edges. Please forgive the shameless plug, but it might be good to read my mini-tutorial at http://www.creativeillusionsphoto.com/virtual.htm. You will find there what can happen if a dome radius is too large or too small. I also have a YouTube video and web page showing the quality of image you can get at http://www.creativeillusionsphoto.com/portsale.htm You may have read about Bill's dome port at http://wetpixel.com/i.php/full/underwater-...s-5-dome-ports/. Bill and I have been working to get an Ikelite fitting dome port assembly to work, using our calculations. He even has a dome shade upgrade that is fashioned after my design. Athena makes a Nexus port to Sea and Sea adapter in case you decide a Bare Dome Port assembly might work for you. I will be happy to add or help with any information that is not clear. All the best, Barry Guimbellot http://www.creativeillusionsphoto.com http://www.marinekeywords.com What extension should I use with a 10-17 Tok and Kenko 1.4x TC when using the Sea and Sea glass dome? I have the SX extension for use without the TC, do I need the extenion ring 22 or 40? cheers Darragh Share this post Link to post Share on other sites