Articles
By David Salvatori
The idea
I have always been keen of the painting technique by the Sixteenth century’s Italian artist Caravaggio. He would position lanterns in specific places of his studio to darken the shadows and transfix the subject in a blinding shaft of light; and through this technique (named “chiaroscuro”), the models are only partially illuminated and Caravaggio managed to highlight the parts of a scene that he deemed more interesting, leaving the rest of the body of the model as a dark, negative space.
I have not been shooting underwater for very long, however from the very beginning I have challenged myself to use the advanced techniques so perfectly described in the creative section on DPG. Among others, the backlighting technique has fascinated me because it lets you play with the effects of light much like Caravaggio did with his chiaroscuro.
For the most part, the backlighting technique has been confined to macro or super-macro shots (for instance, a fantastic backlit blenny by Keri Wilk), where the photographer can manage the light from the strobe easily and fine-tune its position independently (e.g., without the need of an assistant); but I wanted to try this technique in a wider scene, to recreate the Caravaggio’s atmospheres( Editor's Note - backliting has been used in wide angle underwater photography as well, as seen in David Barrio's, and Mark Fuller's Behind The Shot articles, but it is seldom seen with a moving subject like the batfish below.)
The shot
For such a complex shot, where the backlighting strobe cannot be managed autonomously, I needed an assistant- my wife Cristina. The perfect opportunity to accomplish this complex shot finally came during a trip to Indonesia, in the fantastic island of Maratua. Having the chance to dive every day and experiment more than once with these type of shots was fundamental to visualizing and executing the right shot. During night dives on house reef, we noticed batfish hiding under the resteraunt’s jetty, lulled only by a gentle current- a perfect subject for my idea!
For this shot, I positioned Cristina right behind the batfish, perhaps no more than a few feet from the fish. Holding a slave flash set to half power, I placed myself on the other side of the Batfish, about 5 feet away from them. I had a single flash unit set at minimum power and placed in vertical position with the arms fully extended so that the lightning could "leap over" the bats and trigger the slave flash without illuminating the scene from the front. For this specific shot I used a 60mm lens, but this can be tried with medium-range angle lens too (12-24mm for instance). I turned on the aiming light on my wife’s strobe, just to see the light’s direction and indicate to her the right position of the flash.
The “chiaroscuro” effect was further achieved by closing the aperture (f/29 in my shot) and using fast shutter speeds (1/200 sec in my shot). As a result, the biggest problem I had was focusing on the subject with the limeted amount of light available. In the previous night dives, the attempts were unsuccessful because we started the dive too late (so very poor ambient light) and my ISO was too low. For the good shots, we needed some ambient light (we started the dive at 5 PM) and a quite high ISO (ISO 800). The aperture/speed/ISO combination is largely dependent on the environment , the particular subject, amount of ambient light, and clearness of the water, among other factors.
As usual, these fish were frightened by human presence and not really willing to collaborate at first. In our case, the batfish stayed grouped together for a while, so the light from the backlight strobe could no t pass and outline the distinct silhouette of the fish as I would have liked. However, we waited patiently for the them to accept our presence, and finally they spaced out from each other in the water column, seemingly more relaxed. In the first attempts, the backlighting was parallel to the focal plane, and this did not help to create the “chiaroscuro” effect, as a flat light does not show the outline of the “model’s” body in the dark environment.
Finally, placing the slave strobe at about 45 degrees with respect to the focal plane, we were able to create the desired effect, with the silhouette of the second bat on the far right of the picture emphasizing even more the profile of the fishes, as Caravaggio did with his famous paintings.