Dome vs flat port on 28mm lens

[ericpitar]

Greetings,

Given that my canon 28mm lens can be fitted both in a flat and dome port, is there any diffrence in the photos if I choose one port over the other? Perhaps the waterline would be visible in the dome setup?

Thanks in advance.

E

 

[danclem]

Hi Ericpitar:

It would be helpful to know a bit more about the size dome and flat ports you are using, along with information about any port extenders you might be using.

The flat port brings images closer because of the magnification of water. The dome will give you more of a wide angle feel, and you will probably lose some sharpness in the corners. It is almost like having two different lenses. You should be able to use most all of your lenses behing either type of port with the appropriate diopters and/or port extenders.

The dome port is more suitable for in/out water shots, but once again it depends on the size of the port.

Have fun experimenting! We just returned from a two week photo shoot in the Florida Keys where we were experimenting with all sorts of combinations I had never tried. Good results, especially my 60 mm Nikon macro behind a dome port.

Dan

 

[ericpitar]

Hi. It's a 6" dome port. I currently use a flatport for my 28mm lens but wondering the difference if I used a 6" dome port. Thanks for the reply!

e

 

[MarkH]

I would say it depends on what kind of camera you're using. If you have a film or a full-frame digital SLR, then a dome port would allow you to use your lens as it was intended (as a semi-wide). If you have a APS-C or similar sized sensor (most digital SLRs), then a 28mm lens really isn't very wide-angle at all so I'd go with a flat port and use it for "fish portrait"-type shots. The close-focusing distance on a 28mm lens usually isn't very close so you might have trouble focusing using a dome port unless you use a close-up diopter over the lens.