The ExpoDisc (4x5.65") lens mount_Praktica Electronic The Mamiya 645 Pro Tele-Converter

The Mamiya 645 Pro Tele-Converter 2x N is a teleconverter for most Mamiya 645 lenses with focal lengths of 150mm or more

The Fotopro X-4i is a compact tripod with a slightly unusual design: the centre column is “permanently” extended

The Linhof leveling head is essentially a very low-profile ball head with a 15-degree range of motion

some leatherette shrinking

with some cosmetic wear from normal use and handling

The ExpoDisc (4x5.65") lens mount_Praktica Electronic The Mamiya 645 Pro Tele-ConverterThis particular Expodisc is not a disc it's a big 4x5. 65" slab designed to slip into matteboxes but it works the same as the classic. Basically, it's a specialized flat 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.