Contributing Factors
How you acquire your image will affect the resulting dynamic range of
your image. Several people have posted methods of acquiring and
combining images from their digital cameras to increase the dynamic range
but the options are generally quite limited. below are some of the factors
which should be taken into consideration when trying to squeeze the maximum
dynamic range out of your camera.
Digital Cameras
- ISO
- Image format acquired (RAW, TIFF, JPEG)
- Pre-processing (especially sharpening)
The higher figures quoted for the dynamic range of a specific model are
usually acquired with the lowest ISO, at the highest bit depth as a raw
image with no pre-processing. Any changes to these criteria will
create an immediate reduction in dynamic range.
Film scanning
- Choice of film
- Processing variations (choice of lab, pull processing, chemical
changes to developer)
- Dynamic range of scanner
- Bit depth used to acquire the image
- Colour management software
- Pre-processing
- Exposure variation in scanner
As with digital cameras, the best results are usually obtained with the
lower ISO ratings, scanned at the highest bit depth with as little
pre-processing as possible. Colour management software can have a
significant impact on dynamic range although as you start to push the limits
of dynamic range the colour accuracy starts to deteriorate.
Nevertheless there are circumstances where the widest possible gamut can be
used successfully to substantially increase the dynamic range of an image. |
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