Rule of thirds the right demonstrates the application of the rule of thirds. The horizon sits at the horizontal line dividing the lower third of the photo from the upper two-thirds. The tree sits at the intersection of two lines, sometimes called a "power point" or a "crash point". Points of interest in the photo do not have to actually touch one of these lines to take advantage of the rule of thirds. For example, the brightest part of the sky near the horizon where the sun recently set does not fall directly on one of the lines, but does fall near the
Rule of thirds (diving) Rule of thirds (diving) In scuba diving, the rule of thirds is a rule of thumb used by divers to plan dives so they have enough breathing gas remaining in their diving cylinder at the end of the dive to be able to complete the dive safely. This rule generally only applies to diving in overhead environments, such as caves and wrecks, where a direct ascent to the surface is impossible and the divers must return the way they came. For divers following the rule, one third of the gas supply is planned for the outward journey, one third is