Photometric parameters of the Canon EOS 6D Mark II camera
Heading:
| Psaryov, V, Velikodsky, Y, Konichek, V, Sinelnikov, I |
| Kinemat. fiz. nebesnyh tel (Online) 2025, 41(3):44-78 |
| https://doi.org/10.15407/kfnt2025.03.044 |
| Language: Ukrainian |
Abstract: The paper presents metrological parameters of the full-frame camera Canon EOS 6D Mark II photosensor. The working range of output signal levels is from 0.1 to 15870 reference units DN. Depending on ISO parameter value, the sensor solarization takes place when output signal reaches levels from 11318 DN up to 15870 DN. According to the data of laboratory experiments, it is shown that the range of photosensor output signal in area of its linear response to changes in the active light flux is 20.2...20.4 дБ (S = 107.3...11595.6, 142.0...14819.9, 132.2...14309.0 DN in R, G, B channels of the sensor, respectively.) When using the logarithmic function of photosensor sensitivity, the range of its linear response increases to 38.2 дБ (S = 2.24...14819.9 DN). The sensor local response in the R, G, B channels to changes in active light flux is 558.63, 1164.0, 691.37 DN/s at ISO = 100; 1283.5, 955.29, 206.9 DN/s at ISO = 12800 and 4263.6, 3119.2, 698.42 DN/s at ISO = 40000 respectively. The dependence of the sensor output signal level on the ISO value at an exposure time of Texp = 5.2 s remains linear within the entire range of ISO values from ISO = 100 to ISO = 102400 in all spectral channels of the sensor when using a logarithmic dependence lgSe(lgISO). In the case when the sensor transfer function is presented on natural numbers scale, the sensor linear response ranges in R, G, B spectral channels differ and are ISOR,G,B = 1600...102400, 2016...102400, 3200...102400 DN, respectively. In the highest informativeness areas of the sensor linear response ranges signal-to-noise ratio (SNR) of output signal takes values from 5.0 дБ to 34.5 дБ (Rose’s criterion), accordingly the signal increases from 4.5 to 12560 DN and is controlled by the ISO level. Similarly, when the signal intensity depends on exposure duration, at ISO 100 within the sensor linear response ranges, the critical SNR values of output signals are 5.0 дБ at S = 14.0 DN and 47.6 дБ at S = 14820 DN. At ISO 40000, the SNR parameter takes values from 5.0 дБ to 33.6 дБ at signal levels of 160...230 DN and 13522 DN, respectively. Taking into account the results of conducted analysis, the use of digital cameras with a CMOS sensor in photometric studies can be considered acceptable. |
| Keywords: CMOS sensor, digital camera Canon, linear response range, signal level, signal-to-noise ratio |
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