The ExpoDisc (77mm)  type_Flash Coupling 5 Novar Anastigmat lens in

5 Novar Anastigmat lens in a five-speed Velio shutter

clean diaphragm and clean glass

fully tested

fast standard lens for 4x5 cameras

The SMC Pentax-DA* 50-135mm f2

The ExpoDisc (77mm) &nbsptype_Flash Coupling 5 Novar Anastigmat lens inThe ExpoDisc is a clip on (or hold in front of) diffuser designed to facilitate setting custom white balance. Rather than hauling around a gray card, or trying to find a plain white surface, or hoping that your camera guesses correctly, you can toss this in front of your lens and lock in an accurate custom white balance in seconds. Bonus: if you actually use this on a lens with a 77mm filter thread, it can replace your lenscap. Yeah, its just a fancy