Wide angle flat port vs dome

[coweyman]

I have a tg5 in an ikelite case, I am wondering the difference between the 2 types of wide angle ports available. Any input would be great.

Primary I shoot mainly macro but I have a trip to the Philippines coming up and I am sure to see alot of larger creatures.

Thanks

 

[Barmaglot]

A flat port will reduce your angle of view and add pincushion distortion. Here is an example of a 24mm (16mm on an APS-C sensor) lens being shot through a flat port:

And the same shot, same settings, through a dome:

With a TG-5 and an Ikelite housing with dome port, you can use an Olympus FCON-T02 to get actual fisheye performance, but this means sacrificing macro capability for that dive, as you cannot remove this underwater. Alternatively, you can keep the flat port and get a wet wide lens - most of them will give you approximately 130 degree AoV on the wide end, and if you want to take a macro shot, you can unscrew it and put it in your pocket during a dive.