Difference between revisions of "Manta G032 camera measurements"
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This page contains data from the demo I did in lecture on 9/22/2015 of the Manta G032 camera. | This page contains data from the demo I did in lecture on 9/22/2015 of the Manta G032 camera. | ||
− | The point was to measure the gain, dark | + | The point was to measure the gain <math>g</math>, dark current <math>I_d</math>, and read noise <math>N_r</math> of the Manta G032 cameras we use in lab. |
==Measurement procedure== | ==Measurement procedure== | ||
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* 100 frame movie recorded at 20 FPS with an exposure of 150 μs. | * 100 frame movie recorded at 20 FPS with an exposure of 150 μs. | ||
* 100 frame dark movie recorded with identical settings. | * 100 frame dark movie recorded with identical settings. | ||
+ | * Variance of each pixel (noise squared) plotted versus average value (signal). | ||
==Calculations== | ==Calculations== | ||
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* and <math>D_{x,y}[t] is the number of dark current electrons generated during time interval <math>t</math> | * and <math>D_{x,y}[t] is the number of dark current electrons generated during time interval <math>t</math> | ||
+ | Take the variance of the pixel value equation, which is equal to the noise squared. | ||
+ | |||
+ | :<math>\left\langle\left(P_{x,y}-\overline{P_{x,y}}=g\left(\langle I_{x,y}+N_r^2\right)\right)\right\rangle</math> | ||
{{Template:20.309 bottom}} | {{Template:20.309 bottom}} |
Revision as of 19:09, 22 September 2015
Overview
This page contains data from the demo I did in lecture on 9/22/2015 of the Manta G032 camera.
The point was to measure the gain $ g $, dark current $ I_d $, and read noise $ N_r $ of the Manta G032 cameras we use in lab.
Measurement procedure
- Light source directed at the camera so to produce a range of intensities
- 100 frame movie recorded at 20 FPS with an exposure of 150 μs.
- 100 frame dark movie recorded with identical settings.
- Variance of each pixel (noise squared) plotted versus average value (signal).
Calculations
The expression for the value read from pixel $ x,y $ during time interval $ t $ is:
- $ P_{x,y}[t]=g \left(I_{x,y}[t]+R_{x,y}[t]+D_{x,y}(t)) \right) $,
where
- $ I_{x,y}[t] $ is the number of photoelectrons that are generated during interval $ t $,
- $ R_{x,y}[t] $ is the read noise during time interval $ t $,
- and $ D_{x,y}[t] is the number of dark current electrons generated during time interval <math>t $
Take the variance of the pixel value equation, which is equal to the noise squared.
- $ \left\langle\left(P_{x,y}-\overline{P_{x,y}}=g\left(\langle I_{x,y}+N_r^2\right)\right)\right\rangle $