A Blue-eyed Hermit Crab (Dardanus scutellatus) is making its way on a sandy patch close to the Mauritian coast while sifting through the bottom sand in search of food. Although this species occurs in a broad geographical range, from Africa's east coast to the French Polynesian islands in the east and from Japan in the north to the northern parts of Australia in the south, it is a relatively uncommon species.
The Blue-eyed Hermit Crab is easily recognisable by its greyish-blue eyes on white or creamy eyestalks. Also, the longitudinal black-maroon stripes on the basal segments of antennules and antennae, and the brownish/burgundy and blueish white dotted patches on their claws (chelipeds) and legs (pereiopods) are typical for this hermit crab. It feeds usually at night by sifting through sand and sediment in the search for micro-algae, detritus, and zooplankton.
Hermit crabs are not picky when it comes to the model and exact species of the shell they use to protect their soft body parts. The specimen in this underwater video clip has made its home in a discarded pyramidal shell, and it's very unlikely that it uses the entire spires of this turreted-shaped mollusk. The somewhat elongated shape of its armour looks very bulky and seems to hinder the little crustacean in its movements. A much shorter or chunkier shell would have made the hermit crab's movements more efficient. Finding a new, suitable shell is not easy for a hermit crab; competition is fierce in the real estate market. Hermit crabs outgrow their mobile home, and sometimes it even gets damaged by predators.
To keep all movements as natural and realistic as possible I always film in 24 frames per second. By filming in this so called “cinematic” frame rate you create a motion blur that somehow matches how we as humans perceive movement and motion. This motion blur is clearly visible in the frantic movements of the little hermit crab’s claws and legs.
This frame rate has become the industry standard for filmmaking, and there are several reasons behind its popularity.
First, 24 frames per second (fps) allows for a good balance between smooth motion and a sense of realism. When we watch films at 24 fps, it provides a slight amount of motion blur that smoothens transitions between individual frames. This motion blur contributes to a more immersive and lifelike viewing experience, making it easier for our eyes and brains to perceive the action on screen as natural and continuous.
Moreover, 24 fps has historical roots in the film industry. During the early days of cinema, it was chosen as a standard frame rate because it struck a compromise between capturing smooth motion and conserving film stock, which was costly and limited at the time. This decision shaped the way films are made and viewed, and even today, it remains a crucial part of cinematic storytelling.
The 24 fps frame rate also impacts the aesthetics of a film. It has a distinct cinematic look, characterised by the slight but deliberate motion blur, which is often associated with high-quality filmmaking. This aesthetic quality has been ingrained in the cultural perception of what a "movie" should look like, further reinforcing the choice of 24 fps as a standard.
Despite its widespread use, filmmakers occasionally experiment with other frame rates for artistic or technical reasons. Higher frame rates, such as 30 or 60 fps, can provide extremely smooth motion and may be preferable for certain types of content, like sports broadcasts or video games. However, these higher frame rates can sometimes appear less cinematic and may not feel as natural to human perception, which is why 24 fps remains the go-to choice for traditional narrative filmmaking.
This short underwater videoclip has been filmed in Mauritius 🇲🇺
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