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PIXSultan | profile | all galleries >> Technology, Development & Tests >> Canon 20D/30D/5D/1D/1Ds/MKII/N/III tree view | thumbnails | slideshow

Canon 20D/30D/5D/1D/1Ds/MKII/N/III

Testing 1D2/1D2n/1D3 output and results with FLEXSharp, FLEXTone, etc. Samples obtained from other users in DPReview, and other resources.
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SCREEN_SHOT1DMKII_EVU_Recover-1.jpg
SCREEN_SHOT1DMKII_EVU_Recover-1.jpg		 SCREEN_SHOT1DMKII_EVU_Recover-2.jpg
SCREEN_SHOT1DMKII_EVU_Recover-2.jpg		 SCREEN_SHOT1DMKII_5D_DR_JPG-4.jpg
SCREEN_SHOT1DMKII_5D_DR_JPG-4.jpg		 SCREEN_SHOT1DMKII_DR_DPP_C1-1.jpg
SCREEN_SHOT1DMKII_DR_DPP_C1-1.jpg
SCREEN_SHOT5400_II-Film_Noise-1.jpg
SCREEN_SHOT5400_II-Film_Noise-1.jpg		 SCREEN_SHOT1DMKII_DR_C1-1.jpg
SCREEN_SHOT1DMKII_DR_C1-1.jpg		 Screen_Shot1DMKII-C1_FLEXStudio-a.jpg
Screen_Shot1DMKII-C1_FLEXStudio-a.jpg		 SCREEN_SHOTSFR_1DMKII_1DMKIIn-1.jpg
SCREEN_SHOTSFR_1DMKII_1DMKIIn-1.jpg
SCREEN_SHOTSFR_1DMKII_1DMKIIn-2.jpg
SCREEN_SHOTSFR_1DMKII_1DMKIIn-2.jpg		 SCREEN_SHOT1D_1DMKII-Nyquist-1.jpg
SCREEN_SHOT1D_1DMKII-Nyquist-1.jpg		 SCREEN_SHOT1DMKII_AirShow-1.jpg
SCREEN_SHOT1DMKII_AirShow-1.jpg		 SCREEN_SHOT1DMKII_SFR_SharpON_OFF-1.jpg
SCREEN_SHOT1DMKII_SFR_SharpON_OFF-1.jpg
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Norman Koren 25-Nov-2005 18:27
I have made a change to Imatest in version 1.5.5 that affects dynamic range (DR) measurements made with the Stouffer T4110 transmission chart. I have realized that the "indistinct zones" (dark zones where edges between them are not clearly detected) represent valid data. I wasn't sure at first. As a result I have changed Imatest output to report the dynamic range with the indistinct zones as "Total dynamic range," and I changed the former (total) dynamic range to "DR distinct steps only."

This only affects the Total dynamic range display measured with the T4110, where "indistinct zones" are present. It does not affect the DR at the various quality levels (high,...), which may be the best indicators of useable DR.

I am upgrading the documentation to reflect a number of things I've learned. Some publications report the inverse of the f-stop noise as signal-to-noise ratio (SNR). The ISO 15739 noise standard has an extrapolated DR measurement whose intent is to find the dynamic range where SNR = 1, corresponding to "low quality" in Imatest. The ISO measurement, which uses a reflective target with a density of 2, is much less accurate than the Imatest/T4110 technique.

My apologies for the confusion this has caused and is likely to cause in the near future. It will make things clearer in the long run.
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