Two of my friends asked me recently about the black background in photographs. That brought me to an idea to write a blog about three ways leading to dark black colour behind the subject. When I picked the photographs for the blog I realised that I know about at least six techniques. You can certainly come up with more and I would like to know about them.
This technique relies on the Inverse Square Law and works in underwater as well as above water macro photography. The camera is set to register the ambient light as black. The light from strobes will reflect from the subject and paint its picture on the sensor. The light that will miss the subject will travel further and will weaken quickly. If there is nothing in its way, it will never return to the sensor or it will be too weak for the sensor to mind.
Denise's Pygmy Seahorse (Hippocampus denise), Raja Ampat, Indonesia
In practice it means positioning the camera to shoot against water rather than the bottom or piece of rock. Avoid pushing the critter into favourable position. Harassing the subject is frowned upon amongst good photographers. Swimming nudibranchs and octopuses flying against black water may have been helped by the photographer or a dive guide too eager to please their customer. Check Alex Tattersall's Thoughts and strategies for minimising our environmental impact.
Set the exposure so that the image comes out pitch black without strobes. In practice I set the ISO low (100-200) and shutter speed high (1/200-1/320 sec). I close the aperture to f/19 or similar depending on required depth of field and intensity of ambient light. Dial high or maximum power on your strobes. Position your strobes close and alongside the macro port. Experiment with the aperture as well as position and power of your strobes.
In this way you create an image with nicely lit subject in the forefront and black background. Anything in the background that is too close behind the subject will ruin the effect. This method works very well with DSLRs and it is difficult to achieve on compact cameras due to limits in aperture. One should try though.
Low level of ambient light in the night allows to use the previous technique for wide-angle photography. Images of pelagic fish and mammals approaching from the dark are full of mystery. Start with ISO 200, 1/60 sec. shutter speed and f/8 aperture. The positioning and power of the strobes require attention to minimise backscatter. One needs powerful strobes to make it work. Taking pictures in the deep black water without reference to shore or bottom is exciting for the photographer and results can be rewarding.
Ever hungry whale shark (Rhincodon typus) feeding at night at Maldives
Use Photoshop wizardry to mask the distracting original background. This method rarely produces naturally looking pictures, yet it is the one to master. It rectifies many problems arising with the other techniques. Photoshop offers many ways to achieve the same end result, this happens to be one of them.
Open the image in Photoshop
Create a new layer (e.g. by clicking at the ‘Create a new layer’ icon in the lower right corner.
Fill the newly created layer with black colour by pressing Shift-F5 or using menu Edit->Fill… Choose black as Contents.
Add Layer Mask on top of the newly created layer. The easy way is to click on the ‘Add layer mask’ icon whilst holding the Alt key. This will create a black layer mask over the newly created layer.
Select the black Layer Mask.
Choose the Brush Tool from the tool palette on the left hand side or by pressing “b”. Play with the size of the brush (keys ‘[‘ and ‘]’) and its hardness (‘Shift-[‘ and ‘Shift-]’)
Choose white as the colour to paint with. I do that usually by pressing ‘d’ which selects the default foreground and background colours. White happens to be the default background colour. Then I press ‘x’ which swaps the background and foreground color.
Paint with the white Brush Tool over the black Layer Mask outside of the subject. This hides the subject’s original background and reveals the new black background.
Change hardness of the brush tool depending on sharpness of the subject at various places. Be generously soft with the soft focus areas and firm at the sharp edges. Use ‘x’ to swap between black and white brush tool. Use the black brush tool for corrections.
This is torturously time consuming, especially for subject with rugged or hairy contours. Nevertheless, for anything else than a fish with clear contours, the Brush Tool gives me the best results.
Martin Edge has been experimenting with the Inward Lighting technique since 2007 and described it in the 4th edition of his book The Underwater Photographer (Focal press, 2010). I can only agree with Alex Mustard, who, in his book Underwater Photography Masterclass (Ammonite Press, 2016) describes Inward Lighting as the most counter-intuitive of all lighting techniques as it requires the strobes to be aimed at the photographer’s head.
How does this seemingly suicidal technique works?
The strobe produces a cone of light. The trick is to light the subject with the ‘edge’ of the cone of light, so the background stays in the dark. Position the strobes from the side or above the subject and aim them inwards, towards yourself. This method will work with a compact camera, providing it will be equipped with an external strobe.
Take a studio background with you underwater. I bought black, blue and white plastic slates on Amazon. 20x20 cm seemed to fit the bill. They are slightly negatively buoyant and fit into the pocket of my BCD. I found it is easier to ask my buddy to carefully position and hold the slate behind the subject.
Long-snouted seahorse, Croatia © 2016 Niky Šímová
This method, when carefully executed, is much less disrupting to marine life than moving critters into positions where they can be photographed against open water. It will work with a compact camera. Niky Šímová took this beautiful picture while I held a black slate behind the seahorse. Neither of us touched nor disturbed the seahorse in any way. You can find Niky on Instagram and facebook.
Snoot is something you put in front of your strobes to modify the shape of light. Used by portrait photographers for decades, it was made fashionable in underwater photography by Keri Wilk. Almost ten years later the market for "girls' and boys' underwater toys" offers various snoots from simple tubes, fibre-optic cables and one very specific Light Shaping Device (LSD) from Retra UWT. Majority of snoots allows only a small portion of light produced by strobes to light he subject. LSD focuses large proportion of the light from the strobe into a spot of customisable shape. Being the most expensive option it applies its shapeshifting qualities on your light beam as well as your purse.
Have you ever used one of those or a different technique? I would like to know. Please share in the comments below.