From the ground up, the H4D is ideal for aerial photography. The image sensor of the H4D, for example, has been especially selected to provide the flatness required, for such applications advanced mapping.
The H4D Aerial camera also features positive locking of both the digital capture unit and lens, using 4 screws, which are reachable from the inside of the camera. This solution is designed to prevent any unintentional movement that may occur due to aircraft vibration and to ensure that camera calibration remains unchanged.
The digital capture unit’s single locking screw and reinforced bottom support completely eliminate play and movement during flight. The camera also features special firmware that activates the camera and raises the mirror when power is supplied.
Power can be supplied from the standard rechargeable battery grip or from a DC-power grip that runs on 110-240 VAC.
The H4D Aerial camera is delivered without a viewfinder in order to better serve remote control purposes and to fit the standard mounting pods found in the mapping industry. A viewfinder is available.
Communication and interface with the camera is provided via 1394B FireWire 800. Special mapping solutions may also want to take advantage of the socket for remote triggering or the flash-sync socket for precise monitoring of exact exposure timing.
The Hasselblad software library, which can be supplied with the H4D Aerial, enables image tagging with metadata, including the full set of exposure settings, in-lens temperature, and GPS coordinates. Interfacing to portable or on board GPS systems is also supported.
The H4D can also serve as a flexible camera component for mapping systems using multiple camera units in clustered arrays that are used for delivery of unmatched detail and meets the highest professional standards for resolution and coverage*.
The H4D Aerial camera supports synchronized exposures to within 20 μs of simultaneous capture in a multiple camera set-up.
When using multiple cameras to capture high definition images of Earth for mapping purposes, it is extremely important that all cameras expose the sensor at precisely the same time.
If exposure synchronization is slow and/or varying from capture to capture, it becomes much more difficult to merge images in post processing. The H4D Aerial includes a feature that allows up to 8 cameras to be synchronized within 20 μs. A simple bus-type cable connection is required between all cameras in the set-up.
This feature completely eliminates any problems in post production caused by unsynchronized exposures.
*Documentation of image accuracy from multi-camera systems, such as the “dIGIcam” from IGI systems Gmbh, is available from the German DGPF test study of mapping systems.