Instruction manual

Instruction Manual Roundshot D3 - version 4.05 – May 2013 - © by Seitz Phototechnik AG / Switzerland www.roundshot.ch page 56
4.3 … control the exposure
The exposure is influenced by four factors:
• TDI Stages
• ISO/ASA
• Exposure speed
• Aperture
Instead of exposing just one vertical line, the Seitz D3
Digital Scan Back exposes various vertical lines at the
same time which are read out continuously with TDI
technology. In other words, a surface – rather than
just a line – is exposed. This is how the fast capture
speed is possible.
The readout speed of the sensor is synchronised with
the rotation speed of the camera head to allow
perfect positioning and sharpness of the image.
The larger the scan area (the more TDI stages), the
more sensitive is the scan and the faster is the image
capture.
Simultaneous
exposure of the
sensor‘s surface with
simultaneous read-out
(TDI)
TDI Stages
One important benefit of creating additional sensitivity by using TDI stages is that
there is no additional noise.
The available TDI Stages are:
1x, 2.5x, 5x, 10x, 20x
4.3.1 Using TDI Stages to control the exposure
4.3.2 Using ISO/ASA to control the exposure
Just as for traditional digital cameras the Seitz D3 Digital Scan Back can also create
additional sensitivity by using gain. Increasing the gain factor amplifies the signal.
This type of sensitivity is expressed in ISO/ASA values. Increasing gain, however,
leads to additional noise.
The available ISO/ASA values are 100, 200, 300, 400, 600 and 800.