The H3D 31 features a one-piece stainless steel shell over a die-cast aluminum box. Grip surfaces have a rubbery coating, and there are non-structural plastic parts. While nearly all small-format cameras have a horizontal orientation, medium format cameras are laid out front-to-back and are longer than they are wide. **Front**Viewed head-on, the H3D body has a square silhouette slightly larger than the lens mount, with a grip protruding for the right hand, and a viewfinder hump. The fat new 28mm f/4 wide angle lens nearly obscures the H3D 31 when viewed from the front. The name Hasselblad appears in small, slanted type across the top of the body. Two very small buttons and a remote control jack are tucked between the grip and the body. The upper button is labeled M.UP, but it can be assigned to other functions than flipping up the mirror. The STOP DOWN is below the remote jack. Again, it can be assigned to other functions. The remote jack is sealed with a tethered rubber plug. The grip is vaguely mushroom-shaped with a wide top spreading above a relatively straight stem. An autofocus assist light is built into the area where the top of the grip meets the camera body. **Back**The back of the H3D 31 is defined by the back of the 31-megapixel digital back. It features a 2.2-inch LCD. To the left are a button with a dot on it, which brings up menus, and a button with an "i" on it, which brings up the last image shot, and shooting data, including a histogram. To the upper right are buttons labeled "+" and "-" which navigate menus and adjust image magnification. At lower right is a button with red, yellow and green dots on it, which controls the instant image approval system. A rubbery oval in the lower right is a four-way controller for navigating menus and enlarged images. The viewfinder eyepiece is a very large, deep, soft rubber eyecup. It's just above the digital back but not in contact with it. The AE lock button and a user-defined button are between the side of the camera and the back of the grip. Between them is a very small button inset into the surface of the grip. Pressing it with a pen tip will wind out a roll of film, when a film back is on the camera. A large stainless steel button and lever below the control buttons combine to release the battery pack that makes up the gripping surface. **Top**The shutter release button is a large, smooth disk toward the front of the H3D 31's grip. The front control dial pokes up behind, just below the plateau that holds the body's LCD. The 3 buttons across the top of the LCD are labeled FLASH, AF and DRIVE. The 3 down the right side are MENU, LCD backlight and ON/OFF. The ON/OFF button also accesses profiles and works as an escape key. There's a pop-up flash on top of the viewfinder. **Left Side**The lens release button is in the lower left corner of the H3D 31's left side. The prominent plastic panel toward the middle covers a diagnostic port that is not user-accessible. A PC flash sync terminal is to the right of that, along with the latch that releases the camera back. The terminal has a protective rubber cover. The strap lug is small and mounted near the center of the side.
On the digital back, there are two PC sync terminals, for use when the back is on a view camera. In that case, one sync cord runs from the camera shutter to the back, and the other runs to the flash, or preferably, a radio remote control for a flash. A Firewire 800 terminal in the lower right corner allows for tethered use with a Windows or Macintosh PC or with a portable hard drive. The most disarming thing about the back is the large ventilation slots in the sides and the fan inside. A switch for the pop-up flash is on the viewfinder. **Right Side**The media door is on the right side of the back. It's large and plastic, with a metal plate on the inside. A pair of magnets hold it closed. The strap lug that corresponds with the one on the left side is low and near the grip. A lug for a wrist strap is on the outside of the grip. A second control dial pokes out of the back of the grip. The diopter control is toward the back of the right side of the HVD90x viewfinder. The exposure compensation and exposure buttons are a bit forward, within reach from the grip. **Bottom**The H3D 31's tripod socket is centered under the camera body and covered with a large plastic lid that forms a flat bottom with rubberized rails running along the right and left edges. The H3D 31 will sit flat on a table, and the rubber texture will keep it from sliding much.