World of Blur
Underwater photographer NICHOLAS MORE has become associated with motion-blur images, and has a number of awards to show that he has become a master of the technique. Here he shares some of his secrets…
Motion blur is a way of incorporating movement to help create images that capture power and dynamism. A slow shutter-speed is used with either Front Curtain Sync (FCS) or Rear Curtain Sync (RCS), depending on the effect you’re looking to achieve.
FCS, the default sync mode, is used combined with an “accelerated panning” technique. The strobes fire at the beginning of the exposure, freezing the subject.
The movement of the camera (panning) in the direction in which the subject is facing, combined with natural, ambient light, blurs away the background to create those motion effects.
Accelerated panning means moving the camera in time with the subject, triggering the shutter and then continuing to move and accelerate the camera ahead of the subject.
Panning fast or slow will determine how much blur the photographer chooses to render in the final image.
You can either lock the focus (pre-focus) to the back button or use the camera’s autofocus (AF). Modern cameras such as the Nikon D500 have lightning-fast AF, and mine has never let me down.
I also set the AF points to pick out the subject’s eye. You have to control the “pass” of the subject by positioning yourself in the water to encourage it to pass to a particular side.
By using FCS you can accurately compose the shot and position the subject within the frame, via the viewfinder and shutter-release. This allows a much more predictable image.
Panning also helps to remove background distractions such as other divers and their bubbles, as well as backscatter.
Reef and other background objects are rendered with a painterly effect to produce pleasing backgrounds that allow the subject to “pop”. (photo 1)
Appeared in DIVER November 2019
RCS can be used with the camera stationary. The shutter opens at the beginning of the exposure and the strobes fire as it closes.
This allows motion blur to be captured on moving foreground subjects but keeps the background relatively sharp.
The downside to this technique is that you’re not fully in control of the composition, because the subject can be erratic and might not swim through the frame as expected.
When executed well, however, photos shot with RCS have a more natural feel than those shot with FCS. (2)
To shoot motion blur, it’s essential that the camera be set to manual. The flash sync should be set to either FCS or RCS, depending on the look of the shot you’re trying to achieve.
Shutter-speed, which is what allows blurring of the image, needs to be anywhere between 1/4 and 1/15th sec.
The slower it is, the more blur you can achieve. Remember, however, that slowing the shutter-speed will also allow more ambient light onto the sensor, and can lead to over-exposure.
A small aperture (f/16-f/22) helps to minimise ambient light but also to control the strobe light and to guarantee sharp focus of the subject.
The ISO must be set low (50-200), again to minimise ambient light.
Twin strobes should be used on high power, and set behind the camera-housing handles in the quarter-to-three position. It’s the strobe light that “freezes” the subject and the ambient light that allows for the blur, so the trick is to get close to the subject to allow the strobe to overpower any ambient / available light.
Removing strobe diffusers creates “hard” directional light to light and “freeze” only the foreground subject.
“In-lighting” can also work very well, to prevent illumination of the background. This strobe positioning and power would normally result in horrendous backscatter, but with the panning technique the backscatter just gets blurred away, and can even add to the overall effect.
I generally start at ISO 100, 1/8th sec and f/18, with my strobes on almost full power. If it’s very bright, I’ll stop down to ISO LOW/50, 1/15th and f/22, and if too dark, ISO 200, ¼ sec and f/16.
These same settings can be used to produce creative and artistic pictures such as swirls or zoom blurs.
Bright sunshine with the sun directly overhead will result in over-exposure because of the slow shutter-speeds needed for motion-blur effects.
Minimise the ambient light by shooting on cloudy days or early/late in the day. In very bright conditions, neutral density filters can be used to control excessive ambient light.
Not all subjects suit motion blur.
The technique is suited to dynamic subjects or to remove distracting backgrounds, such as the black sand of Lembeh when shooting the benthic residents, or “messy” divers and their bubbles in a wide-angle scene. (3)
Sharks are an obvious choice, but it’s fun to experiment with other subjects to see what works. (4)
In terms of composition, subjects swimming parallel or coming onto the camera work best. It is also essential to have natural separation between the subject and the background.
You do need to have the eye of the subject pin-sharp to engage the viewer, of course, because otherwise the whole image is just a blur!
Shooting slightly up into Snell’s Window, or even into the sun when low
in the sky, renders the surface with a painterly effect and introduces surface suggestion, which is key to the audience engaging with the image.
Objects and people in the background also create depth to the images, and help to lead the viewer through the frame and identify with the picture.
A very nice surface effect can be achieved when there is a slight chop – calm water is less helpful. If it’s perfectly calm, you should be shooting shallow, dappled-light images anyway!
The slow-shutter, motion-blur technique may also be used to produce swirls and other abstract images. (5, 6)
Importantly, motion-blur images need some post-production editing, because they will look slightly flat straight out of the camera.
Using Adobe Lightroom or Photoshop, adding clarity, contrast and vibrance while reducing highlights will allow the images to really pop. (7)
Successful motion-blur images require a lot of practice to refine the skills needed, and experience to recognise potential subjects and situations. Repetition as well as trial and error to find out what works is essential.
Be prepared to commit to the technique, and plan entire dives or even trips to the style to achieve pleasing results.
The images really do stand out, and will boost your portfolio, as well as appealing to judges in competition.