Sunpak DF4000U External Flash

The Sunpak DF4000U External Flash is a universal TTL flash designed for Canon and Nikon DSLR and HDSLR cameras, offering photographers powerful, camera-communicating flash output at an affordable price point. It’s aimed at photographers who want a straightforward on- or off-camera flash without the higher cost of a first-party Speedlite or Speedlight.

The flash offers a guide number of 190 ft. at ISO 100 (also cited at up to 623 ft. depending on measurement conditions), delivering strong light output for a range of shooting situations. TTL technology allows the flash to communicate directly with compatible Canon or Nikon cameras to intelligently calculate exposure, and an auto-zoom flash head senses the attached lens’s focal length, automatically adjusting coverage across an 18-180mm range (with closeup coverage cited from 28-180mm depending on source) to match the field of view being captured.

Handling includes a built-in illuminated dot-matrix LCD display for adjusting settings, along with a slave function for wireless off-camera triggering: S1 mode fires the flash in response to any other flash firing nearby, while S2 mode is designed to ignore a pre-flash and fire only on the main flash pulse, useful when triggered by a camera or flash using TTL pre-flash metering. The flash head swivels 180 degrees to the left, along with vertical tilt adjustment, giving photographers bounce-flash flexibility for softer, more directional light. A built-in bounce card also helps achieve suitable lighting for a subject.

Build quality includes a foot designed for easy installation and removal from the camera’s hot shoe, along with a design that keeps the flash relatively lightweight for handheld freedom of motion, though some users have noted the unit’s overall size and weight as a minor drawback. The flash runs on 4 AA batteries (not included).

Key Features
– Universal TTL flash for Canon and Nikon DSLR/HDSLR cameras
– Guide number of 190 ft. at ISO 100
– Auto-zoom flash head (18-180mm coverage)
– TTL automatic flash exposure control
– Illuminated dot-matrix LCD display
– Built-in slave function (S1/S2 modes) for off-camera triggering
– 180° left swivel head plus vertical tilt adjustment
– Built-in bounce card
– Easy-install/removal hot-shoe foot
– Runs on 4 AA batteries (not included)