40% Focal Length Increase. The Pentax 1.4x HD PENTAX-DA AF Rear Converter AW provides 40% more reach than compatible lenses with only one stop of light loss while retaining autofocus capability.

High-Quality Build. The durable, weather-resistant construction offers peace of mind when shooting in less-than-ideal conditions. It features Pentax’s HD lens coating that maximizes image sharpness through eliminating flare and ghosting. At just 0.8 of an inch thick and 4.4 oz. in weight, you won’t even notice it in your bag.

Compatibility. Due to the recessed elements, this converter supports just about any Pentax K-mount. Both camera-driven focus systems and lens-driven systems (SDM and DC-series) are fully compatible. Please note that autofocus will only work with lenses with a maximum aperture of f/4 or faster.