Underwater Strobe Light
Wow, this picture was actually ruined by the underwater strobe light!
Your underwater strobe light will be a fantastic boon to your photography skills…you can light up the ocean floor and achieve results you can never get without an underwater flash. When the light is dim, as it will be once you get deeper and deeper, the underwater strobe light is essential for capturing the marine world with your camera.
Newbies will be ecstatic the very first time they go out to test their new underwater flash equipment. However, like any new development in photography skills, it will take patience and practice. One of the first things newbies will notice is that the underwater strobe light can sometimes ruin a picture. In some cases, it’s too much and the picture can wind up looking bleached out.
To avoid bleaching out your underwater photos, keep in mind that in some conditions, ambient light is enough. If the water is very clear, and you’re not diving very deep, and you’re taking a picture of some light-colored objects like the coral in the picture above, it may be an occasion to turn your underwater strobe light off.
The problem is, whited out areas on your picture are actually whiter pixels. White pixels contain no information, so you really can’t do much with an overexposed picture once you get home and run it through Photoshop. It’s actually better to underexpose your pictures in underwater photography, especially if you take your pictures in RAW format. You can fix a lot of things with Photoshop, but if your underwater strobe light bleaches out the pixels, there’s not a lot you can do to get a great picture.
For a underwater strobe tutorials check out http://www.uwphotographyguide.com
Underwater Strobe Flash
This Was Taken With an Underwater Strobe Flash
Last time we talked about the underwater strobe flash that’s called a slave strobe, and how it fires when it senses your camera’s built-in flash fires. Then there was the problem of the pre-flash, which is used by your camera to determine light metering. The pre-flash can make your underwater strobe flash go off, which will result in no flash when you’re really taking the picture, during your camera’s main flash.
The good news is that some of today’s underwater strobes can be set for use with a camera that uses a pre-flash. On the Sea & Sea YS-01 underwater strobe flash, for example, there are three settings, or modes:
- use with a camera that pre-flashes
- use with a camera that does not pre-flash
- use with a camera that uses DS-TTL flash
If your underwater strobe flash is set to normal slave function, it will go off when a camera pre-flashes. It will be recharging during your camera’s main flash, which is of course when the picture is actually taken. Result: darkness.
Underwater Cameras and the Preflash
These days, most digital cameras use preflash to determine settings for flash photography. Basically, the digital camera sends out a bunch of flashes before you take the picture…it’s to get a reading on the lighting conditons, and based on the information that comes from the preflashes, the power of the flash and also the duration of the flash are set automatically for your picture.
Because the metering is done while you are looking through the lens, using the lens that actually takes the picture, it’s called TTL. TTL stands for Through the Lens. No separate window is necessary for light metering.
This is the most common method of flash settings on digital cameras. This is how flash metering is done. It’s very different from the old film cameras, which also use TTL flash metering but in a different way. But who actually cares about film photography these days.
Most digital cameras, since they use TTL flash metering, don’t have a hotshoe for attaching an external flash. Therefore, people buying underwater strobes and who have a typical digital camera, will have to use what’s called a slave strobe.
A slave strobe fires when it senses the camera’s built-in flash going off. Going back to what we learned about the preflash, well now you’ve got an underwater strobe that fires while the camera is sending out flashes for metering, not for taking the picture. In other words, slave strobes can fire before your camera is ready to take the picture. But don’t fret, there are solutions!
Why Use Underwater Strobes?
- very blue, very dim without underwater strobe
Did you know that in just ten feet of water light loses half its intensity? And that’s in the clearest tropical water you can find…say in the Bahamas. Now just imagine how much light is lost when the water isn’t that clear.
Then keep in mind that sometimes you go deeper than 10 feet…well most of the time, right? How are divers able to take pictures at all if the water sucks up all the light? And add to that they can’t stand very still and who wants to dive with a tripod. Is that even done?
Because they are diving (i.e. moving), underwater photographers have the added challenge of fewer options when it comes to shutter speed. In other words, slow shutter speeds and a tripod, the typical land-based solution for low light, just won’t work under water.
You can raise the ISO, especially with today’s newest digital cameras, but that can give a very grainy (aka noisy) look to your underwater pictures.
What about using the flash that came with the camera…the built-in flash? Simple: the built in flash is lame and weak, so you’ll have to get very very close to your subject in order for it to have any effect at all. And you can just forget about wide angle photography and your built in flash.
Also, underwater photos tend to look all blue, and that’s because the deeper you go, the less red light you have. At just 30 feet, there’s practically no red end of the spectrum left in your photos.
Well, underwater strobes to the rescue. It’s basically a bigger, stronger flash than what came built into your camera. Here’s a simple list to sum up why people use underwater strobes:
- You can illuminate a wider area.
- You can eliminate backscatter, which is when your flash lights up particles floating about in the water rather then just your subject.
- You will bring out the true colors of the underwater world, including your reds.
- You can use fast shutter speeds to capture things in motion.
