IDE Database - MOS sensor photographs
This pages gives you access to all the photographs that were taken of
the IDE MOS sensors, both preflight and postflight images. Please be
sure to read the notes on the scanning procedures below to get
familiarized with contrast and brightness setting used.
Sensor Photographs by LDEF Bay Position
Sensor Photographs by pre- or postflight
Sensor Photographs by Sensor type
Sensor Photographs by Sensor ID Number
Image scan procedure notes
This not is intended to provide information on scaling and contrast
settings used for the scan. Note that contrast and brightness
settings for the scanned varyied from one (original) photograph to
another and was changed from image to image.
A 202 mm by 254 mm (8 in by 10 in) photograph of a sensor looked
like this:
Hardware used for scanning:
- 486DX "no name" PC with 4 MB RAM and ET4000-equipped video
card
- Hewlett Packard ScanJet IIc
Software used for scanning:
- MS Windows version 3.1 running in enhanced mode, using a 256-
color ET4000 video driver at a resolution of 800 by 600
- Scanning software provided with the scanner (DeskScan II
Version 1.6.1) calibrated as described in the manual to the screen
used
Procedure:
- scan overview of the image (Preview-button)
- zoom in using a near-quadratic box covering the sensor plus the
black margin
- use a rectangle that covers the central part of the sensor only,
then adjust brightness and contrast using the Auto Exposure
button
- use a rectangle that covers the whole sensor
- Scan the image as "Black and White Photo" (i.e., 256 grays), Type
"Screen" (i.e., 75 dpi), scale factor of 78% (i.e., 432 by pixels) as "TIFF
5.0 Compressed".
Except for the final alignment of the selection box and the typing of
the file name, all steps were performed using a macro and the
Windows 3.1 macro recorder.
Allthough the scanner manual does not explicitly state what
algorithm it uses to determine the "Auto Exposure" contrast and
brightness settings, this feature provides a somewhat consistent way
of scanning the photograph as no subjective adjustments are
possible. Note, however, that the appearance of feature in the scans
might not directly reflect the actual feature. If you want to
compensate screen brightness and contrast and software effects, click
here to retrieve a scan of the front cover of a (clean) copy of the
LDEF 2 proceedings, Part 3. It was scanned using the exact same
procedure.
The filenames reflect the sensor ID number and the wether this is a
pre- or postflight photograph. I had to do the latter classification by
myself since all I had was stacks of prints for each tray with sensor
photographs, ordered by sensor ID and, post- and preflight image. I
used the presence of impacts and the presence of a debris pattern
close to the contacts (if present) or the appearance of the sensor's
contamination patterns to base my judgement upon.
It may be possible that I use incorrect filenames. Time constraints do
not allow me to re-check all of the scans. You may base your
judgement of pre- or postflight image upon the same or different
criteria.