Tips, ideas and advice for budding underwater photographers
by Nick Robertson-Brown FRPS
Part 1: Getting to grips with your camera settings – Aperture
When you look at your subject underwater, without using artificial light, there are essentially three factors that you can change on your camera to create the image you want. These three factors are aperture, shutter speed and ISO and all three have an effect upon how the image will look. Each will have their own individual characteristic upon the outcome of your image, and usually, by changing one of these factors, one of the others will need to be adjusted to compensate for what you have done. In order to maintain the same amount of light in your image, the exposure value (EV), increasing the light from one of these factors will mean you need to decrease the light using one of the other two.
It is a case of balancing the light to get the right value for the image you want to create. How you balance this value will give you, the photographer, control of how you wish the image to look. In this first article, we are going to look at Aperture.
The aperture is the space behind the lens through which the light enters the camera, and hence, the sensor. The aperture works very much in the same way as the pupil of the human eye. In bright light, the pupil will close down to a small round opening, hence restricting the amount of light that falls on the retina. As it gets darker, the pupil dilates to allow more light to enter the eye. The aperture of the camera’s lens can be opened and closed, just like the pupil of the eye, and if you have your camera in the auto setting, this is one factor the camera may use to change the exposure value. This is why I think it is important that you should use the manual setting so you have control of how you want to present your image.
The aperture setting is referred to as the f-stop or f-number, and the smaller the number, the larger the aperture. Mechanically, the size of the hole is determined by a circle of blades that cause the central aperture to open and close by the overlapping of these blades on each other. Closing the aperture will restrict the amount of light hitting the sensor and the f-number increases. This f-number is not just a random figure, but is in fact a ratio of the focal length of the lens to the physical size of the aperture. In most compact cameras there is no mechanical closing of an aperture but its attributes are produced electronically to give the same effect.
The figure above shows the f-value and all camera lenses are calibrated using the same f-stop scale. The range of aperture numbers does vary from one lens to another, with the greater range generally equating to the greater price. The scale, however, is always constant and each increase in f-stop number equates to half the amount of light that is allowed through to the sensor.
Depth of Field
Opening and closing the aperture, or decreasing and increasing the f-stop, would appear to be a simple way of changing the light level on the sensor. As the aperture is opened however, the depth of field is reduced, and this has a very noticeable effect upon the image. The depth of field is defined as the amount of the image which appears to be acceptably in focus, and changing the depth of field on your subject can create very different images.
As you can see from the above image, the pygmy seahorse is in sharp focus. The rest of the coral behind it is totally out of focus, and this has the effect of making the seahorse, your subject, pop out from the picture.
And again with this ghost pipefish, the subject is in focus, but the background is blurry and there can be no misunderstanding as to what the subject is.
This does not necessarily mean that you should always use a small depth of field to make your subject pop out, and there are times when the environment around the subject is important. This technique is used by many underwater photographers as it allows you to virtually eliminate any messy background by using a low f-stop number to create a small depth of field. This is ideal for when your subject will not come out into the open. The blurry background in an image is called “Bokeh”
Of course, sometimes you want to show the critter in its environment and to do this, you need to increase the f-stop (close down the aperture). As a result of closing down the aperture, the exposure value will go down as you are letting less light onto the sensor. Within the exposure triangle, there are two other factors you can adjust and I will be looking at these controls next time.
Do you want to learn more? You can pick up a copy of Nick’s book “Underwater Photography Art & Techniques” by clicking here.
Underwater Photography Courses
Frontline workers honoured with free dive trip to Yap
The remote island of Yap in the Federated States of Micronesia is among the few places in the world that remains free of Covid-19 thanks to its ocean border and a strict travel ban that has kept its residents safe.
Nonetheless, Yap has been affected, too. As one of the world’s premier, award-winning destinations for divers, this paradisiacal location in the western Pacific Ocean has had no outside visitors to its rich shores and reef for nearly a year. But while there may be no virus, the island hasn’t been cut off from the economic impact experienced around the globe.
That didn’t stop Bill Acker, CEO and founder of the Manta Ray Bay Resort and Yap Divers, from doing something, though.
Last March, soon after the island went into lockdown, Bill began to realize the effect of the virus on daily life beyond the island. “Yes, we are closed, have no divers, had to send our employees home and prepare for difficult times,” he said. “But we’re lucky in that we have, for the most part, avoided the human suffering and death this pandemic has caused.”
Thinking about the problems faced by his family business, they paled when he compared them to those endured by the healthcare workers who have been fighting selflessly around the clock for months on end for the well-being and lives of others.
“One evening, while checking the news online, I saw pictures of frontline workers who were tending to desperately ill and dying people when families and friends could not be with their loved ones. It was heartbreaking,” he added.
The next day, a meeting was held with the resort’s staff and Bill invited suggestions for ways they could do something to honor healthcare workers. The result was the idea to award twenty divers who are working on the frontline to save other’s lives during this pandemic while risking their own, with a free week at the resort.
Divers around the world who had been guests at Manta Ray Bay in the past were invited to submit the names of candidates for the award by December 31, 2020. “We received nominations for 126 individuals from as far away as Germany, the U.S., Australia and Canada,” he said. “It was not easy choosing the winners but our committee of staff members took on the job and selected the 20 finalists.”
“While trying to choose the people to reward for their hard work during this Covid-19 crisis,” Bill added, “by reading the nominations we saw that every one of the nominees was doing things above and beyond the call of duty. Sadly, we don’t have the finances to offer over 100 free weeks in Yap, but we do want to recognize the contributions all of them are making to our world. So, we are offering the rest of the nominees a free week of diving in Yap which includes room, hotel tax, airport transfers, breakfast, diving and Wi-Fi. The only requirement is that they travel with at least three other people and stay in two rooms or more.”
“We do not yet know when Yap will open its borders,” said Bill, “but when it does, we will welcome these important guests to Yap to relax and dive with the manta rays and the other beautiful denizens of the ocean surrounding our island home. They are the true heroes of this devastating, historic time and we look forward to honoring them with a well-deserved dive vacation.”
Watch out for our exclusive trip report from a healthcare worker from the UK who is one of the 20 to have been awarded this amazing dive trip!
For more information on Manta Ray Bay and Yap Divers visit their website by clicking here.
Dream Dive Locker Build Out. Part I: Demolition (Watch Video)
It’s finally here! Time to start building the greatest dive locker the world has ever seen! Part I: Demolition! #dreamdivelocker
This is the first of a series of videos showing the evolution of building out my dream dive locker. My dream dive locker needs to be dive gear drying and storage, dry storage, workshop, office, editing suite, You Tube studio and classroom. That’s a lot of functions for a small space!
The first step is planning out the space and demolishing the laminate flooring. Then I taped up the walls to get a feel for the space. We have a lot of work to do!
But finally we will have a purpose built space to house all of our dive equipment! Subscribe to our channel to follow our progress!
Thanks for watching, Team!
Subscribe here: http://bit.ly/DiversReady
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