Kodak classifies their imaging detectors according to the number and type of "defects" found on the CCD. The word "defects" has a rather negative sound to it, but in fact most CCD have some defects in the form of warm or cool pixels. It does not mean that any CCDs other than Class 0 are "defective" in any way. Defects are pixels that usually still function but they respond to light slightly differently than their neighboring pixels and therefore look lighter or darker than the rest of the pixels that surround them. These "warm" or "cool" pixels are easily removed from an image during processing. On large arrays such as those used in the ST-8E and ST-10E a few warm or cool pixels are often lost to the eye among the millions of other pixels in the image. Large detectors with no defects are usually very expensive and are not needed for most applications.
SBIG has always tried to offer the best value for the money when it comes to the class of detectors we choose. Where a Class 1 detector is priced reasonably, we use it. If the detector is relatively free of column defects, this is generally good enough for the vast majority of applications. Even the effect of a column defect is easily removed from an image using CCDOPS software.
However, Kodak has now eliminated column defects from Class 2 or better CCDs so we can now say that no matter which camera you select with the standard detector there will be no column defects. In the tables below we provide the information from Kodak's data sheets regarding the various classes of detectors. The definitions for defects varies slightly from one detector to another so we have included each definition under the table for a given CCD.
The Class of detector provided as standard for a given model of camera is shown in bold typeface with grey highlighting in the table. Higher classes of detectors are available as options for any camera unless otherwise indicated. These detector classifications are offered as an indication only. Please refer to Kodak for the latest detector cosmetic classification.
|
ST-7E (KAF-0401E/LE) |
Point Defects |
Cluster Defects |
Column Defects |
|
Class O |
0 |
0 |
0 |
|
Class 1 |
Up to 5 |
0 |
0 |
|
Class 2 |
Up to 10 |
Up to 4 |
0 |
Definitions for KAF-0401E (Non-ABG)
Point Defect: DARK: A pixel which deviates by more than 6% from neighboring pixels when illuminated to 70% of saturation, OR BRIGHT: A Pixel with dark current > 5000 e/pixel/sec at 25C.
Cluster Defect: A grouping of not more than 5 adjacent point defects
Column Defect: A grouping of >5 contiguous point defects along a single column, OR A column containing a pixel with dark current > 12,000e/pixel/sec, OR A column that does not meet the minimum vertical CCD charge capacity, OR A column which loses more than 250 e under 2Ke illumination.
Neighboring pixels: The surrounding 128 x 128 pixels or ±64 columns/rows.
Defect Separation: Column and cluster defects are separated by no less than two (2) pixels in any direction (excluding single pixel defects).
Defect Region Exclusion: Defect region excludes the outer two (2) rows and columns at each side/end of the sensor.
Definitions for KAF-0401LE (ABG)
Point Defect: DARK: A pixel which deviates by more than 6% from neighboring pixels when illuminated to 70% of saturation, OR BRIGHT: A Pixel with dark current > 3000 e/pixel/sec at 25C.
Cluster Defect: A grouping of not more than 5 adjacent point defects
Column Defect: A grouping of >5 contiguous point defects along a single column, OR A column containing a pixel with dark current > 6,000e/pixel/sec, OR A column that does not meet the minimum vertical CCD charge capacity, OR A column which loses more than 250 e under 2Ke illumination.
Neighboring pixels: The surrounding 128 x 128 pixels or ±64 columns/rows.
Defect Separation: Column and cluster defects are separated by no less than two (2) pixels in any direction (excluding single pixel defects).
Defect Region Exclusion: Defect region excludes the outer two (2) rows and columns at each side/end of the sensor.
Defect Separation: Column and cluster defects are separated by no less than two (2) pixels in any direction (excluding single pixel defects).
Defect Region Exclusion: Defect region excludes the outer two (2) rows and columns at each side/end of the sensor.
|
ST-8E KAF-1602E/LE |
Point Defects Central 600x800 |
Point Defects Total |
Cluster Defects Central 600x800 |
Total Cluster Defects |
Column Defects Central 600x800 |
Column Defects Total |
|
Class 0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Class 1 |
Up to 2 |
Up to 5 |
0 |
0 |
0 |
0 |
|
Class 2 |
Up to 5 |
Up to 10 |
Up to 2 |
Up to 4 |
0 |
0 |
|
Class 3 |
Up to 10 |
Up to 20 |
Up to 4 |
Up to 8 |
Up to 2 |
Up to 4 |
Definitions for KAF-1602E (Non-ABG)
Point Defect: DARK: A pixel which deviates by more than 6% from neighboring pixels when illuminated to 70% of saturation, OR BRIGHT: A Pixel with dark current > 5000 e/pixel/sec at 25C.
Cluster Defect: A grouping of not more than 5 adjacent point defects
Column Defect: A grouping of >5 contiguous point defects along a single column, OR A column containing a pixel with dark current > 12,000e/pixel/sec, OR A column that does not meet the minimum vertical CCD charge capacity, OR A column that loses more than 250e under 2Ke illumination.
Neighboring pixels: The surrounding 128 x 128 pixels or ±64 columns/rows.
Defect Separation: Column and cluster defects are separated by no less than two (2) pixels in any direction (excluding single pixel defects).
Defect Region Exclusion: Defect region excludes the outer two (2) rows and columns at each side/end of the sensor
Definitions for KAF-1602LE (ABG)
Point Defect: DARK: A pixel which deviates by more than 6% from neighboring pixels when illuminated to 70% of saturation, OR BRIGHT: A Pixel with dark current > 3000 e/pixel/sec at 25C.
Cluster Defect: A grouping of not more than 5 adjacent point defects.
Column Defect: A grouping of >5 contiguous point defects along a single column, OR A column containing a pixel with dark current > 6,000e/pixel/sec, OR A column that does not meet the minimum vertical CCD charge capacity, OR A column which loses more than 250 e under 2Ke illumination.
Neighboring pixels: The surrounding 128 x 128 pixels or ±64 columns/rows.
Defect Separation: Column and cluster defects are separated by no less than two (2) pixels in any direction (excluding single pixel defects).
Defect Region Exclusion: Defect region excludes the outer two (2) rows and columns at each side/end of the sensor.
|
ST-9E (KAF-0261E) |
Point Defects |
Cluster Defects |
Column Defects |
|
Class 0 |
0 |
0 |
0 |
|
Class 1 |
Up to 10 |
Up to 4 |
0 |
Definitions for KAF-0261E (non-ABG only)
Point Defect: DARK: A pixel which deviates by more than 20% from neighboring pixels when illuminated to 70% of saturation OR BRIGHT: A pixel whose dark current exceeds 4500 electrons/pixel/second at 25°C.
Cluster Defect: A grouping of not more than 5 adjacent point defects.
Column Defect: (1) A grouping point defects along a single column. (Dark Column). (2) A column that contains a pixel whose dark current exceeds 150,000 electrons/pixel/second at 25 C. (Bright Column). (3) A column that does not exhibit the minimum charge capacity specification. (Low charge capacity). (4) A column that loses >500 electrons when the array is illuminated to a signal level of 2000 electrons/pix (Trap like defects).
Neighboring Pixels: The surrounding 128 x 128 pixels of ± 64 columns/rows
Defect Separation: Defects are separated by no less than 3 pixels in any one direction.
|
ST-10XE KAF-3200E |
Point Defects Central 1544x1040 |
Point Defects Total |
Cluster Defects Central 1544x1040 |
Total Cluster Defects |
Column Defects Central 1544x1040 |
Column Defects Total |
|
Class 0* |
0 |
0 |
0 |
0 |
0 |
0 |
|
Class 1 |
Up to 2 |
Up to 5 |
0 |
0 |
0 |
0 |
|
Class 2 |
Up to 5 |
Up to 10 |
Up to 2 |
Up to 4 |
0 |
0 |
|
Class 3 |
Up to 10 |
Up to 20 |
Up to 4 |
Up to 8 |
0 |
Up to 4 |
|
* Note: Kodak does not yet offer this detector in a Class 0 |
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Definitions for KAF-3200E (Non-ABG only)
Point Defect: DARK: A pixel which deviates by more than 6% from neighboring pixels when illuminated to 70% of saturation, OR BRIGHT: A Pixel with dark current > 5000 e/pixel/sec at 25ºC.
Cluster Defect: A grouping of not more than 5 adjacent point defects
Column Defect: (1) A grouping of >5 contiguous point defects along a single column, (2) A column containing a pixel with dark current >12,000 e/pixel/sec (bright column), (3) A column that does not meet the minimum vertical CCD charge capacity (low charge capacity column), (4) A column which loses more than 250e under 2Ke illumination. (trap defect).
Neighboring pixels: The surrounding 128 x 128 pixels or ±64 columns/rows.
Defect Separation: Column and cluster defects are separated by no less than two (2) pixels in any direction (excluding single pixel defects).
|
ST-1001E (KAF-1001E) |
Point Defects |
Cluster Defects |
Column Defects |
|
Class 1 |
Up to 20 |
2 |
0 |
|
Class 2 |
Up to 40 |
Up to 10 |
2 |
|
Class 3 |
Up to 80 |
Up to 20 |
Up to 10 |
Definitions for KAF-1001E (Non-ABG only)
Dark Defect: A pixel which deviates by more than 20% from neighboring pixels when illuminated to 70% of saturation
Bright Defect: A pixel whose dark current exceeds 4500 electrons/pixel/second at 25°C
Cluster Defect: A grouping of not more than 5 adjacent point defects.
Column Defect:
(1) A grouping point defects along a single column. (Dark Column
(2) A column that contains a pixel whose dark current exceeds 150,000
electrons/pixel/second at 25 C. (Bright Column)
(3) A column that does not exhibit the minimum charge capacity specification.
(Low charge capacity)
(4) A column that loses >500 electrons when the array is illuminated
to a signal level of 2000 electrons/pix. (Trap like defects)
Neighboring Pixels: The surrounding 128 x 128 pixels of ± 64 columns/rows
Defects are separated by no less than 3 pixels in any one direction.