Dome Port Essentials for Underwater Image Makers

One of the most frequently discussed topics on the Wetpixel forums is the selection of appropriate dome ports. Many topside photographers assume that the dome's function is simply to provide a waterproof port and tend to be unaware of the fact that it also acts as a critical component in an underwater optical system. Alex and Adam discuss how ports can make or break the quality of imagery that can be produced underwater.
This episode has been kindly sponsored by Salaya Beach Houses: (www.salayabeac...) in Dumaguete, Philippines.
See Alex's work at www.amustard.com
Wetpixel is the source for all things to do with underwater imaging: wetpixel.com

[@sfiron]

I have the Ikelite 8 inch dome port and can't find an easy to use cover...does anyone know of any alterative to their awful cover?

[@rebelrebel2676]

so lens should be very close to dome port front glass or as far as possible from front glass?

[@divercraig65]

Great information once again, thanks!

[@Jylakir]

Thanks for the short discussion on this topic. Do you also plan do make a comparison between "normale wide lens + dome port", "fisheye lens + domeport" and "normal lens + flat port + wetoptics". I would realy like to know which system performs better for which use case.

[@Wetpixel-Live]

I think we do in the video? Rectilinear = "normal"

[@garrryc4332]

Thanks for this very useful vedio！I'm a beginner underwater photography. Planning to have a 8' acrylic dome port from Nauticam. Do you have any suggestion for me to avoid or fix the acrylic dome port going up?

[@Wetpixel-Live]

Glad it was helpful!

[@abdulmajidalghamdi2802]

I wish you talked about the close -up filter and how it effects using dome port underwater. It is confusing since some articles suggested that using close-up filters behind the dome port is essential to be able to have sharp images. Plus which of the power of the close-up filter such as +2,+3 and +4 to use?

[@mikkosport2300]

You need a closeup lens only if your lens is not capable to focus close enough. During the film era this was the situation quite often. With modern lenses - especially with fisheyes - this is not an issue any more. With small domes this may be an issue..The dome forms in water a negative lens . The virtual image seen by the lens is at least four dome radius away from the cener of the dome i.e. 3 from the dome surface. That is the minimum distance the lens should focus.

[@Wetpixel-Live]

What he said-it is impossible to cover each individual lens and haw to set it up in a video. Your source for information like this is the Wetpixel forum...wetpixel.com/forums/

[@khourytalal]

thank you that was helpful

[@Wetpixel-Live]

Glad it helped

[@lucacrudeli787]

Adam, I sent you a couple of emails but I do not seem to get a response from you. I do not know how to reach you, so I am trying this route. 1) I wanted info on the Wetpixel November/December trip to Lembeh. Latest status and thinking. 2) I do not seem to be able to post on the Wetpixel forum. I do not seem to have posting rights. Could you help me please? my user id there is sluca. Thank you! Hope you are well.

[@Wetpixel-Live]

I have been diving! I think we are now fixed?

[@lucacrudeli787]

@@Wetpixel-Live Yes. Thank you for help! I envy you! I want to go diving too!