Dome Port

[netmage]

Whats the function of a dome port.....?

I've seen a video rig with a Inon UWL-100 (wide angle lens) & Dome port. And even in the green quarry - the lenses pick up alot of ambient light.

 

[dsafanda]

You've answered your own question. A dome port is simply a port for wide angle lenses.

 

[f3nikon]

You've answered your own question. A dome port is simply a port for wide angle lenses.

Actually you can put a wide angle lens in a flat port. The curved dome port gives you back the most of the lens angle of view that you will be losing UW. Example, if your lens angle on land is 90 degrees, it will have a 30% lens angle LESS UW because the bending effect the water has on the flat lens port. By bending the port in a dome shape you get back most of the lens angle that you lost.

Your flat lens port dive mask is the same thing, notice that UW everything seem closer and the viewing angle is less than on dry land.

The bottom line on why we what the widest lens angle UW is so that we can shoot at a very close range, 1 foot or less to include much of the scene as possible and reducing backscatter. Shooting this close on land with a wideangle is just plain crazy, but then there is no backscatter on land...well in LA maybe.


http://home.swipnet.se/marinls/domeuw.html

Dive Safe

 

[fdog]

Dome ports are used primarily for wide angle lenses; as well described by f3nikon, you can shoot without being limited by the angle of refraction.

Dome ports have other advantages, too. If Aquatica still made their dome ports for macro, I'd have one.

Light that passes through an interface at an angle will refract. This splits the light out into a rainbow of colors. In macro photography, this is seen as chromatic abberation in the corners. Domes have the light passing through at right angles, and do not suffer from chromatic abberation, and are usually more contrasty as well.

All the best, James

 

[ssra30]

For practical purpose, Inon UWL-100 will give you about 90 degree view. Add Inon domeport, you will get either 130 or 150 degree view (I think there are 2 different domes now, the newer one claimed to give bigger field of vison). This number was for using with Oly C5050 with the lens set at 35mm. Other camera/lens combo may vary.