Cathy Church is a pioneer in underwater photography. Learn about what Cathy Church thinks about Vivid-Pix Land & Sea Scuba and how she uses it.
Cathy Church literally wrote the book(s) on underwater photography. Enjoy her techniques here and join her around the globe. Marty Snyderman’s articles have graced dive magazines for decades. Learn here and join him in the Philippines.
The first two images discussed in this blog were created in oceans that are halfway around the world from each other. In addition to that, the images were created were significantly different camera systems. The shot of the rosy-lipped batfish resting on the sand was created with a macro lens at Costa Rica’s Cocos Island.
In all of my previous blogs I have written about techniques involving things you want to consider or do during a dive. This blog is a bit different in that I will be discussing some things that you will want to do before your dives as you prepare and assemble your camera system.
One of the pitfalls for underwater photographers, especially newer shooters, is failing to have their subject fill a pleasing percentage of their photographic frame. All too often, the result is a fantastic subject that is too small in an image. In short, the best way to describe a picture like that is “an opportunity lost”.
This is so cool...
Pardon me for the dated use of “cool.” I don’t have a better way to express what I feel.
I live in upstate New York, USA. No, not skyscrapers and concrete...this is primarily farm country. Think apples and dairy cows. And I actually enjoy living on what many people would consider the frozen tundra. As my daughter says, “The cold does not seem to affect you the way it does most people.” Yes. This is one of the positive attributes of Swedish and German heritage.
Heritage aside, it is absolutely great that I receive images from all over the world. Since I am responsible for the support of our Vivid-Pix software programs, I often have the chance to receive imagery captured by people on dive expeditions all over the globe. I can’t tell you how great this is. Don’t stop.
If you watch new underwater photographers as I have over the years, you would surely see that a significant percentage of them that try to take pictures of dozens of subjects on almost every dive. I often explain their style as “shooting at anything with gills”.
Though certainly not the norm, occasionally some photos can come out grainy.
When an image is very dark, or very low contrast, the potential for graininess rises. In particular, when your camera is forced to boost the low light level that it captures, the image may become grainy. You may not realize this is happening because cameras generally make this boost automatically. And some cameras do this boosting much better than others.
In order to enhance the contrast so that we see the image in a more dynamic and pleasing way, we are essentially amplifying the differences between pixels. If the image contains a good amount of visual noise (unwanted small image artifacts), the noise is amplified along with the image and becomes more noticeable in the form of graininess. There are filtering techniques that can be applied to reduce this, and we use them, but they must be used sparingly lest the image become “cartoony” due to over-smoothing the image.
Also, when an image is sharpened, it tends to bring out the graininess. Sharpening amplifies the differences between pixels, and visual noise or grain is exactly that...differences between nearby pixels. We have chosen a sharpening technique that minimizes this effect by attempting to sharpen only the actual “edges” of the objects in the image, but the technique is not perfect. Also note that the effect shows differently with different image content. For example, you rarely see graininess in the sand, but a “clear” blue background makes it obvious. Grain is also reproduced differently in different size images, with small images like our side by side being more prone to the problem than larger image files.
“Have underwater camera. Will photograph fish”.
I think this mantra applies to just about every underwater photographer in the world. After all, colorful fishes are one of the underwater world’s feature attractions, and for photographers many species are simply irresistible. But despite all of the things that fishes have going for them- color, beauty, eye-catching antics and fascinating behaviors etc.- it is still possible to take rather boring photographs of even some of the more handsome fishes.
So just what is lightness and contrast?
In an image, lightness (or brightness) is the overall light level. The picture of an eel in a coral crevasse at 30 feet is a good example of an image without much lightness, unless you illuminate it with a strobe. A dolphin just under the surface can be an example of an image with high lightness.
But wait a minute…that dolphin may be nicely illuminated by the rays of the sun entering the water just a few feet above, but the odds are that the picture you took is not very close. The light bouncing off the dolphin and into your camera is filtered and lessened by the water in between. So that dolphin image may not have much lightness, even though the mammal is nicely lit. A better example of high lightness is a coral fan close to the surface, motionless or nearly so, allowing you to get close so that your camera can soak up all that light.
Related, but slightly different, is contrast. A good way to imagine contrast is as the difference between the brightest and darkest portion of the image. For that coral, it’s the brightest part, probably near the top (hopefully not bleached) where the angle reflects the sun best toward you, and the darkest shadow, lower down where the sun does not hit at the moment you clicked the shutter button.
In almost every underwater photography class I teach, when the subject is lighting and strobes students are quick to ask a question regarding how many strobes they should use. My answer usually comes in the form of a question, or several questions. That’s the way I teach. I want students to think about the potential answers and my reasons for answering the way I do instead of trying to memorize my answer and simply accepting it.
While there are many techniques for sharpening, some yield better results than others. We have selected one with a counterintuitive name...Unsharp Masking. Why? Because it tends to accentuate the important parts to the image without increasing visual noise or graininess.
Unsharp Masking actually began as a clever technique to enhance the sharpness of printed images in the chemical/analog world. Digital Unsharp Masking is uses a similar technique, and works something like this:
- It’s good to determine what should be sharpened, so edges are detected. This is in effect “applying a mask” so that only those parts of the image that are significant enough to enhance are subject to sharpening. In other words, those areas that may have small differences from pixels to pixels, like water in the background, are not subject to sharpening, while the intricacies the fish scales are sharpened.
- A threshold is applied. If the change from one part of the image to another at an edge is small, the edge is not sharpened. If the threshold is set high, only major transitions are sharpened. In particular, if you are seeing graininess and pixellation, set the threshold higher.
Here’s A Question For You
Let’s assume you want to create an image that has a strobe-lit, colorful foreground subject and properly exposed water in the background. If you are diving in rather dark, greenish water as you might be in New England, California, Oregon and Washington etc., would you want your strobe to emit a brighter light (more powerful strobe or higher power setting on your strobe) because the water at depth is not brightly lit by the sun, or would you want a less power, thus light that is not as bright, to be emitted from your strobe?
It is always fun to add any new twist that you can think of for your underwater photography. I decided to experiment with things that were orange. I selected out lots of photos that I already had, and I also went on a few dives looking for anything with orange. I was very lucky and found my absolute favorite but elusive subject, the gaudy clown crab (Platypodiella spectabilis).
Muck diving. The term hardly sounds appealing, but in many popular diving destinations muck diving is the rage. As the name suggests, muck diving involves diving in areas where the sea floor is mud, clay or sand, preferably black sand in an area near where a freshwater river empties into the sea. Thus, muck diving habitats are considerably different than a kelp forest or coral reef where the vast majority of sport diving has been done for years.
I think it fair to say that dolphins have a special place in the hearts and minds of a lot of divers. We admire their aquatic skills, obvious intelligence, and social nature. And we appreciate the fact that dolphins just have a way of lifting our spirits and bringing out the best in us whenever they appear.
Have you ever wondered how people find these huge red finger sponges on the same dive where you saw only little ones? The answer is that these ARE the little ones you saw but photographed very close with an extremely wide-angle lens that includes everything within a 180º diagonal area. That means that you can stand very close to your 8 foot wall at home and get the entire wall from floor to ceiling in your photo from just a few inches away.
In many respects digital photography has a lot in common with analog photography, meaning the use of film. For example both digital and film cameras use f/stops, shutter speed and ISO to govern exposure. Another commonality is that at depth the use of strobe light is required to “paint in” colors back into foreground elements. If not for the use of strobe light those colors would be lost from the selective filtration of white light from the sun that occurs as sunlight passes through the water column.
One of the taller hurdles for most underwater photographers to overcome is consistently acquiring proper exposures. One reason that so many of us struggle with exposures is that traditionally speaking we tend to talk about images in terms of the lens being used – a macro vs. a wide-angle lens- as opposed to the exposure scenario.
It makes perfect sense that underwater photographers want to create images with colorful subjects surrounded by inviting blue water. After all, that is the way the tropical ocean so often looks to our eyes when we dive, and the reason that many of us pay the big bucks to travel to destinations that are not in our own backyards.