The exposure triangle consists of Aperture, Shutter Speed, and ISO. Focal Length is related to the field of view and magnification, not directly to exposure.

The aperture controls the size of the opening in the lens, thereby regulating the amount of light that reaches the camera's sensor.

Aperture values typically used in underwater photography range from f/8 to f/16, as they provide a good balance between depth of field and light transmission. f/32 is generally not used due to its excessive depth of field and potential diffraction effects.

Shutter speed determines the duration of time that the camera's sensor is exposed to light. It is used to control motion blur, allowing photographers to freeze fast-moving subjects or create a sense of motion by blurring moving elements.

Shutter speeds commonly used in underwater photography range from 1/125 to 1/500, depending on the desired effect and lighting conditions. 1/1000 is typically not used as it can result in overexposure, especially in bright underwater environments.

ISO determines the sensitivity of the camera's sensor to light. A higher ISO value makes the sensor more sensitive, allowing for brighter images in low-light conditions, but also introducing more noise.

ISO values commonly used in underwater photography range from ISO 100 to ISO 400, as they provide a good balance between image quality and noise levels. ISO 1600 is generally not used due to its high noise levels, which can degrade image quality.

White balance is used to adjust the color temperature of underwater light, which can vary depending on the depth, water conditions, and ambient light. Proper white balance ensures accurate color reproduction and prevents color casts in underwater images.

Common white balance settings used in underwater photography include Auto White Balance, Underwater, and Fluorescent. Incandescent is not typically used as it is intended for indoor lighting conditions, which are not encountered underwater.

Strobes or external lighting are used in underwater photography to provide additional light, which is often necessary due to the absorption and scattering of light underwater. This helps improve exposure, color reproduction, and overall image quality.

Common types of strobes used in underwater photography include Manual Strobe, TTL Strobe, and Slave Strobe. Ring Flash is not typically used as it is primarily designed for macro photography and does not provide sufficient coverage for wide-angle underwater shots.

A dome port is used on an underwater camera housing to reduce the amount of water between the lens and the subject. This minimizes refraction and distortion caused by the water, resulting in sharper and clearer images.

Common types of dome ports used in underwater photography include Hemispherical Dome Port, Fisheye Dome Port, and Wide-Angle Dome Port. Flat Port is not typically used as it does not provide the same benefits in terms of reducing refraction and distortion.

A focus light is used in underwater photography to assist in focusing on subjects in low-light conditions. It projects a beam of light onto the subject, making it easier for the camera's autofocus system to lock onto and achieve sharp focus.

Common types of focus lights used in underwater photography include Continuous Focus Light, Strobe-Triggered Focus Light, and Video Focus Light. Manual Focus Light is not typically used as it requires manual adjustment of the focus beam, which can be challenging underwater.