The Coolpix 8400 employs a very rugged and durable magnesium chassis.

The Coolpix 8400 features a 3.5x optical Zoom-Nikkor lens with a focal length coverage of 24-85mm (35mm equivalent) and a maximum aperture of F2.6-4.9. The lens features a 7-bladed diaphram for true depth of field effects and has ten settings at 1/3EV steps up to a minimum aperture of f/7. The lens is constructed of 10 elements in 7 groups (one Extra-Low Dispersion [ED] lens and two aspherical lenses); all glass, Nikon Super Integrated Coating (SIC) applied

The optional WC-E75 (0.75x) wide-angle converter takes the Coolpix 8400's lens even wider to an unmatched 18mm of coverage. And the brand new TC-E3PF 3x teleconverter which is smaller and lighter than the existing TC-E3ED (3x) teleconverter. Also available is the FC-E9 (0.2x) fish-eye lens as well as polarizing and neutral density filters.

Employing a 5-area Multi AF focusing system, the camera can automatically select the "best" focus point or you can select it manually. The autofocus range is 1'8" (50 cm) to infinity in normal mode or from 1.2" (3 cm) to infinity when in macro mode. It features an AF-assist illuminator for accurate focusing even in poor lighting conditions.

The viewfinder is a tiny 0.44" color LCD with 97% coverage and dioptric adjustment. Anything that can be displayed on the large color LCD (menus, settings, preview and review) can also be displayed on the shielded EVF.

The builtin flash operates in the following modes: Auto Flash, Flash Cancel, Fill Flash, Slow Sync, Red-Eye Reduction, Rear Curtain and Repeating for stroboscopic effects.

The flash working range is 1'8" - 19' 8" (0.5-6 m) in Wide angle and 1'8" - 9'10" (0.5-3 m) in telephoto.

Using the hot shoe, the Coolpix 8400 can be fitted with an external i-TTL speedlight such as the Nikon SB-600 or the SB-800 (SB-50DX shown but usable only in Auto). The built-in Speedlight can be cancelled when using an external flash or used in tandem. The Coolpix 8400 can control the SB-600 or SB-800 motorized zoom head but does not use its more powerful AF-assist lamp.

The Coolpix 8400 features a fully articulated, 1.8", 134,000-pixel, polysilicon color TFT LCD. It can rotate 270° and tilts forward up to 180° for self-portraits. It's illuminated by an LED backlight with adjustable intensity and has a frame coverage of approximately 97% when used as a live viewfinder.

When not in use the color LCD can be turned to face inwards and closed against the back of the camera. It can also be closed facing outwards like other cameras with fixed LCD screens.

The Power switch is located around the shutter release. The FUNC button lets you quickly select either of two user-configurable shooting modes. Next to that are the Flash Mode and Exposure Compensation buttons. The "light bulb" button illuminates the data LCD.

The Mode Dial has positions for Play, Auto, Program AE, Shutter speed priority, Aperture priority, Manual, Scene, Movie and Setup. In addition it also allows you to quickly change the Image Size or Quality, ISO speed and White Balance.

Controls on the rear - The AE/AF-L button is for locking the exposure and/or focus. The zoom buttons function in playback as the INDEX and ZOOM controls. Top right is the Command Dial used for changing various settings. The MENU button calls up the menu system. The QUICK (review) button displays the last image captured in 1/4-screen over the live preview, in playback it lets you create a smaller size image. The 4-way selector lets you navigate menus and make selections, it lets you select images during playback. The trashcan button is for deleting images in playback, in record mode it is the Self-timer button. The DISPlay button controls the amount of data overlayed on the active display. The monitor SELect button switches between EVF and LCD displays. The MF-AF button selects the desired focus mode.

The Coolpix 8400 is equipped with a CompactFlash Type II card slot that allows the use of Type I or II CF cards or Microdrives. (Nikon only "approves" Sandisk, Lexar Media and Renesas Technology CF cards and IBM/Hitachi Microdrives.)  The Coolpix 8400 is FAT and FAT32 compliant so it can be used with devices >2GB in capacity.

On the right side is the DC IN jack (not shown)   And on the left side is the USB 2.0 port and the A / V port. The video format is user selectable between NTSC and PAL. The camera has both a microphone and a speaker builtin.

The Coolpix 8400 comes with the new Nikon EN-EL7 7.4V 1100mAh li-ion rechargeable battery pack. The EN-EL7 can power the camera for approx. 260 shots per charge.

The EN-EL7 battery pack is charged outside of the camera with the supplied MH-56 charger. This is a small and compact (100-240 VAC) charger that can fully replenish a depleted pack in about 150 minutes.

The optional MB-CP10 battery pack can also be used, it is powered by six AA alkaline, lithium, or NiMH batteries.

It seems as if maybe somebody is finally listening to us - Nikon is now including the ML-L3 infrared remote shutter release with the Coolpix 8400. It's very handy for doing self-portraits or when using macro mode on a tripod. The shutter delay is settable for 3 or 10 seconds.