Customer Support
+34 972 661 661
Price (inc. VAT)
Price (inc. VAT)
Price (inc. VAT)
Price (inc. VAT)
Price (inc. VAT)
Price (inc. VAT)
Price (inc. VAT)

Glass vs. Acrylic:

Image quality: Both glass and acrylic perform very well and optical are very similar underwater.
Price: The decisions between the two is often made on price. Acrylic domes tend to be about half the price or less of a similar sized glass dome.
Flare: Glass handles flares and shooting into the sun much better than acrylic. If your shooting style includes the sun in many of your wide angle shots than try to stick with glass. Acrylic domes often show reflections in these type of images.
Durability: Glass is much harder to nick or scratch but minor damage to acrylic domes can usually be repaired with polishing kits.
Balance: Glass domes tend to be better balanced and weighted underwater. Acrylic domes, especially the larger size ones, tend to tilt port up due to the buoyancy of the port.
Weight: Acrylic dome is lighter
Splits: Glass tends to shed water better for split images but you can still receive good results with acrylic.

Flat Port or Dome Port:

For underwater photography with wide angle lenses, the dome port is the best choice, but if the shot starts or ends above water, or if you need to shoot a close-up with a macro lens, the flat port should be used.

Flat Port: The flat port is unable to correct for the distortion produced by the differences between the indexes of light refraction in air and water. Using a flat port introduces a number of aberrations when used underwater. They are:

  • Refraction – This is the bending of light waves as they pass through different mediums of optical density (the air inside the camera housing and the water outside the lens port). Light is refracted 25 percent, causing the lens to undergo the same magnification you would see through a face mask. The focal length of your lens also increases by approximately 25 percent.
  • Radial Distortion – Because flat ports do not distort light rays equally, they have a progressive radial distortion that becomes more obvious as wider lenses are used. The effect is a progressive blur, that increases with large apertures on wide lenses. Light rays passing through the center of the port are not affected because their direction of travel is at right angles to the water-air interface of the port.
  • Chromatic Aberration – White light, when refracted, is separated into the color spectrum. The component colors of white light do not travel at the same speed, and light rays passing from water to glass to air will be unequally bent. When light separates into its component colors, the different colors slightly overlap, causing a loss of sharpness and color saturation, which is more noticeable with wider lenses.

Dome Port
: The dome port is a concentric lens that acts as an additional optical element to the camera lens. The dome port significantly reduces the problems of refraction, radial distortion and axial and chromatic aberrations when the curvature of the dome’s inside radius center is placed as close as possible to the nodal point of the lens. When a dome port is used, all the rays of light pass through unrefracted, which allows the “in-air” lens to retain its angle of view. Optically a “virtual image” is created inches in front of the lens. To photograph a subject underwater with a dome port you must focus the lens on the virtual image”, not the subject itself. The dome port makes the footage marks on the lens totally inaccurate for underwater focus. Therefore lenses should be calibrated underwater. The dome port offers no special optics above water and functions as a clear window
Do you have any doubts?