Photographer uses red-dot gunsight as AF assist
Frustrated with his poor hit rate when capturing seagulls, photographer Chris Malcolm decided to equip the barrel of his 500mm telephoto prime lens with a gun sight intended for a rifle.
Typically, telephoto lenses can be difficult to handle due to their focal lengths, but with his contraption, Chris was able to use the gun sight's battery-powered red LED light to aid his aiming. This helped greatly improve the number of shots he considered "keepers."
The photographer had initially tried mounting the gun sight on his camera's hot shoe, but realized that using cardboard to attach it to the lens barrel reduced the chances of a parallax error.
While the idea is helpful, we do wonder if it's wise to be seen in public with a gun sight in hand. You may want to check with the local authorities before trying this out. Animal lovers, however, can rest easy as the red-dot gun sight don't emit a strong beam like laser gun sights, which can have harmful effects on living things.