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The Canon 5D Mark II Digital Camera Review:
Sensor Noise, Dynamic Range, and Full Well Analysis

by Roger N. Clark

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They may not be used except by written permission from Roger N. Clark.
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This page shows an analysis of noise, dynamic range, and full well capacity of a Canon 5D Mark II camera.

Procedures for performing this analysis are described in: Procedures for Evaluating Digital Camera Noise, Dynamic Range, and Full Well Capacities; Canon 1D Mark II Analysis

The lowest possible noise from a system detecting light is the noise due to Poisson statistics from the random rate of the arrival of photons. This is called photon statistics, or photon noise. Noise from the electronics will add to the photon noise. Noise in Canon 5D Mark II images is limited by photon statistics at high signal levels and by electronic noise from reading the sensor (called readout noise) and noise from the downstream electronics at very low signal levels. In the case of high signal levels, a system that is photon statistics limited enables us to directly measure how many photons the sensor captures, and by increasing the exposure, we can determine how many photons are required to saturate the sensor. That is called the full well capacity, or simply, maximum signal capacity. With data on the lowest noise to the highest signal, we can then determine the dynamic range of the sensor.

The data and analysis results below show how the canon 5D Mark II sensor performs. Table 1 shows the results and these results are shown on the graphs at Digital Sensor Performance summary for comparison with other cameras.

              Table 1
-------------------------------------------------
               Apparent  Maximum     Measured
  ISO  Gain   Read Noise  signal    Dynamic range
       e/DN  (electrons) (electrons)   stops

   50  4.2     24.2       65700       11.41
  100  4.1     23.5       59400       11.30
  200  2.03    11.9       29700       11.20
  400  1.01     6.4       14800       11.18
  800  0.51     3.7        7425       10.97
 1600  0.25     2.5        3710       10.54
 3200  0.127    2.5        1860        9.54
 6400  0.063    2.5         930        8.54
12800  0.032    2.5         460        7.54
25600  0.016                230

 
Pixel pitch: 6.4 microns.
S/N on 18% gray card, ISO 100 = 103.
Sensor Full Well Capacity at lowest ISO: 65,700 electrons.
Sensor dynamic range = 65700/2.5 = 26,280 = 14.7 stops.
ISO at unity gain (scaled to 12 bit) = 1600 (14-bit unity gain = ISO 404).
Low Light sensitivity Factor: 640.
Apparent Image Quality, AIQ = 109
All data derived by R. Clark, December, 2008. 

Values in the above table are described at Digital Sensor Performance summary.

Table 2 shows the noise as a funnction of ISO in image form. The images illustrate several things: 1) lower banding noise at higher ISOs. 2) Better detection of smaller signals at higher ISOs (the random noise decreases). 3) At a certainl high ISO, improvements decrease, meaning there is no benefit to higher ISO. Note, ISO is a post sensor gain and does not increase sensitivity. Increasing ISO digitizes a smaller range (see Table 1) but does improve the noise floor up to a point. Some will find the pattern noise objectionable in ISO 1600 images in shadow areas and night photography. At lower ISOs, the pattern nosie is particularly bad. There is still significant pattern noise at the highest ISOs. For night and low light photography, I usually use ISO 3200 with this camera.

Table 2a. Apparent Read Noise, Central Image
ISO 50
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 6972 electrons
max= 7385 electrons
mean= 7170 electrons
standard deviation= 44.54 electrons
ISO 100
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 6799 electrons
max= 7209 electrons
mean= 7006 electrons
standard deviation= 43.33 electrons
ISO 200
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 3396 electrons
max= 3612 electrons
mean= 3505 electrons
standard deviation= 21.91 electrons
ISO 400
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 1669 electrons
max= 1826 electrons
mean= 1752 electrons
standard deviation= 11.57 electrons
ISO 800
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 817 electrons
max= 935 electrons
mean= 876 electrons
standard deviation= 6.66 electrons
ISO 1600
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 383 electrons
max= 489 electrons
mean= 439 electrons
standard deviation= 4.47 electrons
ISO 3200
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 158 electrons
max= 277 electrons
mean= 220 electrons
standard deviation= 4.49 electrons
ISO 6400
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 48 electrons
max= 167 electrons
mean= 110 electrons
standard deviation= 4.49 electrons
ISO 12800
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 9 electrons
max= 120 electrons
mean= 55 electrons
standard deviation= 4.42 electrons
ISO 25600
Image Range:
-20.00 to 20.00 electrons about the mean

Central 500 x 300 pixel statistics:
min= 0 electrons
max= 91 electrons
mean= 28 electrons
standard deviation= 4.47 electrons

Table 2b. Apparent Read Noise, Full Image, sub-sampled
ISO 50
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 6881 electrons
max= 10892 electrons
mean= 7167 electrons
standard deviation= 45.79 electrons
ISO 100
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 6751 electrons
max= 10636 electrons
mean= 7003 electrons
standard deviation= 44.88 electrons
ISO 200
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 3369 electrons
max= 6939 electrons
mean= 3504 electrons
standard deviation= 22.54 electrons
ISO 400
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 1657 electrons
max= 5356 electrons
mean= 1752 electrons
standard deviation= 11.62 electrons
ISO 800
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 792 electrons
max= 4593 electrons
mean= 876 electrons
standard deviation= 6.88 electrons
ISO 1600
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 351 electrons
max= 4009 electrons
mean= 439 electrons
standard deviation= 4.66 electrons
ISO 3200
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 153 electrons
max= 3374 electrons
mean= 220 electrons
standard deviation= 4.60 electrons
ISO 6400
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 41 electrons
max= 1753 electrons
mean= 111 electrons
standard deviation= 4.56 electrons
ISO 12800
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 0 electrons
max= 868 electrons
mean= 55 electrons
standard deviation= 4.50 electrons
ISO 25600
Image Range:
-20.00 to 20.00 electrons about the mean

Full image statistics:
min= 0 electrons
max= 442 electrons
mean= 28 electrons
standard deviation= 4.58 electrons


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References

1) CCD Gain. http://spiff.rit.edu/classes/phys559/lectures/gain/gain.html

2) Charge coupled CMOS and hybrid detector arrays
http://huhepl.harvard.edu/~LSST/general/Janesick_paper_2003.pdf

3) Canon EOS 20D vs Canon EOS 10D and Canon 10D / Canon 20D / Nikon D70 / Audine comparison
http://www.astrosurf.org/buil/20d/20dvs10d.htm

4) http://www.photomet.com/library_enc_fwcapacity.shtml

5) Astrophotography Signal-to-Noise with a Canon 10D Camera http://www.clarkvision.com/astro/canon-10d-signal-to-noise


Notes:

DN is "Data Number." That is the number in the file for each pixel. I'm quoting the luminance level (although red, green and blue are almost the same in the cases I cited).

16-bit signed integer: -32768 to +32767

16-bit unsigned integer: 0 to 65535

Photoshop uses signed integers, but the 16-bit tiff is unsigned integer (correctly read by ImagesPlus).

The sensor analysis was done with custom, in-house written software. Raw data were extracted from the camera raw files using DCRAW. Custom software read that data and all processing was done in 32-bit floating point.


Back to: Digital Camera Sensor Analysis pages on this site: http://www.clarkvision.com/articles/index.html#sensor_analysis

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First published December 2010.
Last updated November 17, 2013.