Wednesday, February 25, 2009

Scuba diving for Underwater

The Scuba was designed for use with Underwater, because a human like us cannot stay with a few times in Underwater. So many diver created and developed the Scuba accessories for use in the place that they want to explore.

Scuba diving

The scuba meaning from Wikipedia show below;

SCUBA (Self Contained Underwater Breathing Apparatus) diving is swimming underwater, or taking part in another activity, while using a scuba set. By carrying a source of breathing gas, the scuba diver is able to stay underwater longer than with the simple breath-holding techniques used in snorkeling and free-diving, and is not hindered by air lines to a remote air source. The scuba diver typically swims underwater by using fins attached to the feet. However, some divers also move around with the assistance of a DPV, commonly called a "scooter", or by using surface-tethered devices called sleds pulled by a boat.
Scuba diving is still evolving, but general classifications have grown to describe various diving activities. These classifications include:
• Commercial diving
• Military diving
• Naval diving
• Police diving
• Professional diving
• Recreational diving
• Rescue and recovery diving
• Scientific diving
• Technical diving
o Cave diving
o Cavern diving
o Deep diving
o Ice diving
o Wreck diving

Moreover if you want to explore or going down the Underwater, you must have Scuba certificate. Scuba diving requires certification, which can be done through a number of scuba diving agencies, including SSI, NAUI and PADI. Scuba certification agencies are all basically the same in everywhere around the world. You also need this license for hiring the scuba options from scuba shop.

Monday, February 16, 2009

Underwater Flash

Wide-angle image of French angelfish with proper balance between flash and sunlight
The use of a flash or strobe is often regarded as the most difficult aspect of underwater photography. Some common misconceptions exist about the proper use of flash underwater, especially as it relates to wide-angle photography.

Underwater Flash

Generally, the flash should be used to supplement the overall exposure and restore lost color, not as the primary light source. In situations such as the interior of caves or shipwrecks, wide-angle images can be 100% strobe light, but such situations are fairly rare. Usually, the photographer tries to create an aesthetic balance between the available sunlight and the strobe. Deep, dark or low visibility environments can make this balance more difficult, but the concept remains the same. Many modern cameras have simplified this process through various automatic exposure modes and the use of through-the-lens (TTL) metering. The increasing use of digital cameras has reduced the learning curve of underwater flash significantly, since the user can instantly review photos and make adjustments.

Color is absorbed as it travels through water, so that the deeper you are, the less reds, oranges and yellow colors remain. The strobe replaces that color. It also helps to provide shadow and texture, and is a valuable tool for creativitiy.

An added complication is the phenomenon of backscatter, where the flash reflects off particles or plankton in the water. Even seemingly clear water contains enormous amounts of this particulate, even if it is not readily seen by the naked eye. The best technique for avoiding backscatter is positioning the strobe away from the primary plane of the camera. Ideally, this means the flash will not light up the water directly in front of the lens, but will still strike the subject. Various systems of jointed arms and attachments are used to make off-camera strobes easier to manipulate.


When using macro lenses, photographers are much more likely to use 100% strobe light for the exposure. The subject is normally very close to the lens, and the available sunlight is usually not sufficient. There have been some attempts to avoid the use of flash entirely, but these have mostly failed. In shallow water, the use of custom white-balance provides excellent color without the use of strobe.

In theory one could use color filters to overcome the blue-green shift, but this can be problematic. The amount of shift would vary with depth and turbidity, and there would still be a significant loss of contrast. Many digital cameras have settings that will provide color correction, but this can cause other problems. For example, an image shifted toward the "warm" part of the spectrum can create background water which appears gray, purple or pink, and looks very unnatural.

There have been some successful experiments using filters combined with the RAW image format function on some high-end digital cameras, allowing much more detailed manipulation in the digital darkroom. This approach will probably always be restricted to shallow to moderate depths, where the loss of color is less extreme. In spite of that, it can be very effective for large subjects such as shipwrecks which could not be lit effectively with any strobe. Natural light photography underwater can be beautiful when done properly with subjects such as upward silhouettes, light beams, and large subjects such as whales and dolphins.


Although digital cameras have revolutionized many aspects of underwater imaging, it is unlikely that flash will ever be eliminated completely. From an aesthetic standpoint, the flash often adds "pop" and helps to highlight the subject. Ultimately the loss of color and contrast is a pervasive optical problem that cannot always be adjusted in software such as Photoshop.

Sunday, February 1, 2009

Gift for this Valentine’s Day

This Valentine’s Day, amaze and entice your partner with a gift so romantic and exotic, the excitement starts before the box is even opened. Imagine the anticipation on his/her face when a box arrives directly from Provence, France with the name affixed! But the fun is just beginning because no matter which of our tantalizing Valentines you select, it will unquestionably exceed their most expectant imaginings.

Valentine's Day collection

Most popular gift for Valentine's Day are flowers, chocolate and cards. Flowers have symbolized the essence of the day. On this special day, whether it is a single flower or a garland, the sole expression reflected is the message of love. Roses are the ultimate romantic flower, and the most popular present for Valentine’s Day. White roses are for love, red roses are for passion, and yellow roses are for friendship. Lilac roses are the choice to symbolize love at first sight.

Red Roses signify passion or strength of feeling, yellow roses stand for love, and white roses traditionally reflect innocence. A dozen red roses are considered to be a gift of love, while a single long stemmed red rose is usually seen as a passionate gift. You can also send Valentine flowers to your parents, grandparents, favorite aunt or uncle or even the kids. It is the perfect time to remember the people you love. Valentine flowers will brighten the day for those residing in care facilities. It’s a good time to thank people, too. Think about all the people in your life that you would like to thank. Maybe it’s a coworker or boss, special friend or teacher.

Valentines Day Flowers Online at 1-800-Florals

There are many choices when you want to send Valentine gifts. Roses are always a favorite but you might want to choose tulips, lilies, orchids or a stunning combination of exotic flowers and chocolate or candy. Nowadays, flashy and ostentatious gifts are the priorities for the day, anyway this in no way undermines the significance of flowers.