According to foreign website Nikon Rumors, the instruction manual for one of Nikon's lenses, "Nikkor Z 400mm f/2.8 TC VR S", has a warning stating that "if the user implants a pacemaker or other medical device, the device should not be used." The magnets built into this device may affect the normal operation of the medical device."
▲ Nikon Nikkor Z 400mm f/2.8 TC VR S lens, with a new design and the use of SSVCM (Smooth High Speed Voice Coil Motor) for the first time.
In this regard, the photography blog PetaPixel made further explanations, pointing out that the problem mainly comes from the autofocus motor of this lens. The Nikon Nikkor Z 400mm f/2.8 TC VR S lens has a completely new design and, for the first time, uses SSVCM technology (Smooth High Speed Voice Coil Motor) to provide a faster, more precise and quieter focus performance, although the magnet used by this motor may be too strong, resulting in a magnetic field that may affect the normal operation of pacemakers or other medical instruments. PetaPixel believed that Nikon had caused serious results in order to avoid improper use of lenses, so it made this rare warning.
▲SSVCM (Smooth High Speed Voice Coil Motor) provides faster, more accurate and quieter focus performance.
PetaPixel also cites the American Heart Association to explain that the magnetic field of a magnet can suppress the pulse generator of a pacemaker or defibrillator. If these medical instruments are implanted on the body, avoid close or prolonged contact with magnets or other magnetic fields. The magnet should be placed at least 6 inches (about 15cm) away from the implanted instrument. Considering that the photographic equipment is often placed on the chest, the safe distance may not be enough, so it is responsible for Nikon to make this warning statement.
▲The warnings listed on page 6 of the Chinese Traditional version of the manual.
In fact, the electronic devices commonly used around us, including smartphones, tablets, smart watches and even headphones, basically have magnets. For example, as apple's official website explains, almost all of its main products contain magnets or related parts that generate magnetic fields. However, it may be that the magnetic force required by Apple's digital products is different from the lens, and Apple only recommends that users should maintain a distance of 6 inches (about 15cm) from the medical instruments in the body when using the product; maintain a distance of 12 inches (about 30cm) when charging; when the medical instrument is suspected to be affected, discontinue the relevant products and immediately seek assistance from a doctor or the manufacturer of the instrument.