[Hover on a thumbnail to see the caption; Click on a thumbnail for a larger picture]
Photos from Sandilands-Selective-Cutting project site on 2003oct15:
These are wide-angle shots taken straight up from the middle of each of the 24 test plots; taken to
determine the canopy-closure; have converted each to Black&White, then counted the number of Black
pixels, using standard Linux utility programs: pgmtopbm and pbmhist;
each is 200x150=30,000 pixels, so the black pixel count over 30,000 gives the percent-shade:
04550-plot07-50: 82.5%
04557-plot06-50: 74.2%
04566-plot05-50: 74.9%
04573-plot04-50: 82.4%
04580-plot03-50: 82.8%
04587-plotT1-50: 79.8%
04593-plot02-50: 78.2%
04600-plotT2-50: 84.8%
04606-plot01-50: 90.3% (wrong focal-length)
04613-plot19-50: 69.5%
04619-plot18-40: 60.7%
04625-plot17-40: 61.8%
04631-plot16-50: 79.1%
04638-plot15-40: 57.0%
04644-plotT4-35: 39.5%
04650-plot14-40: 60.2%
04656-plot13-40: 74.3%
04662-plotT3-40: 80.6%
04668-plot12-50: 71.6%
04675-plot11-25: 38.8%
04681-plot10-45: 48.7%
04687-plot09-45: 84.3%
04695-plot08-45: 78.3%
04702-plot20-35: 16.8%
-- I have 2 shots from many plots; the difference is usually less than 0.5
(percentage points), but as much as 2 or 3, especially when I get my hat into a photo
-- unfortunately at plot01, my zoom-lens was not at the wide-angle setting
-- most are converted to B&W using: pgmtopbm -threshold -val 0.50; but
some photos are so dark that clouds become black,
so they are done with -val 0.45 or 0.40 or 0.35; here is an example,
showing the colour photo, the overdark B&W version, and the "correct" B&W version:
![]() 04644-plotT4: | ![]() (with 0.50: 67.5%) | ![]() (with 0.35: 39.5%) |