“Now You Can Combine Underwater and Abovewater Scapes in One Photo” – this is the title of an article I read today that totally captured my attention. I spend a few neurons this summer trying to capture both the lake bottom and the sky without loosing colors and details. If the colors problem could be solved by shooting in RAW, using gradient filter and making vertical panoramas, the details of the lake bottom were always lost.
The secret is related to split photography.
With optimal lighting conditions and high water transparency, the level of illumination under the water is one f-stop less intensive than above the water. Early in the morning and at the end of the day, when sun rays fell on the water surface at an angel, this difference is even higher, it reaches 3 f-stops. Thus the best time for split photography is from 10 am to 2 pm, when the sun is high in its zenith. However, the level of illumination of two parts of a split is different, even if the conditions are ideal. It means that it is impossible to set an ideal exposure – either the upper part will be overexposed, or the bottom part will be underexposed.
The thing I did not thought about:
When we shoot with a wide-angle lens, we use a spherical port as well. Under the water a spherical port forms a kind of additional ‘lens above the main one. As a result we can see a picture above the port (about 30-50 cm above), which is called a virtual picture. If a wide-angle lens focuses on a virtual picture underwater, then any subject above the water which is situated farther than 30-50 cm will be out-of-focus. To solve this conflict, use a magnifying attachment. Usually it is a filter put on the lens. Part of this filter is transparen’t, and the other part is a magnifying lens.
[tags]split photography, photography tutorials, photo tips[/tags]