Processed images from London, September 2004

The first image in a row is a standard jpeg as stored within the original raw file (*.raf, for Fuji S5000) -- a scene as processed by the own camera software.

Each second image in a row shows luminance coded by colours (each colour corresponds to another power of ten, scale is logarithmic; mean red is 1 cd/m2, mean green is 10 cd/m2)

Each third image has a grid overlay. Average luminance of each tile is written at its bottom (in cd/m2). (The middle number in each tile is a median value of green pixels.) Each fourth image has the same grid overlaid on colour-coded lumiances.

Luminance scale / 1
  cd/m<sup>2</sup>
Logarithmic luminance scale (the unit is candela per square meter) – intensities of snow illuminance in lux would be obtained by multiplying the numeric value of luminance by 3.6. For asphalt, such a coefficient is between 20 and 40 (or much less, for specular reflections of distant lamps)

Indoor ones, from the Childhood Leukaemia conference, lecture by Richard Stevens

01.jpeg 01.png 01g.jpg 01g.png

02.jpeg 02.png 02g.jpg 02g.png

03.jpeg 03.png 03g.jpg 03g.png

04.jpeg 04.png 04g.jpg 04g.png

06.jpeg 06.png 06g.jpg 06g.png

London at twilight

07.jpeg 07.png 07g.jpg 07g.png Westminster bridge over Thames, Parliament and Big Ben are shown. Glare from the lamps on the bridge becomes prominent already.

08.jpeg 08.png 08g.jpg 08g.png

09.jpeg 09.png 09g.jpg 09g.png

London by night

10.jpeg 10.png 10g.jpg 10g.png

11.jpeg 11.png 11g.jpg 11g.png

13.jpeg 13.png 13g.jpg 13g.png

14.jpeg 14.png 14g.jpg 14g.png

16.jpeg 16.png 16g.jpg 16g.png

18.jpeg 18.png 18g.jpg 18g.png

20.jpeg 20.png 20g.jpg 20g.png

21.jpeg 21.png 21g.jpg 21g.png

22.jpeg 22.png 22g.jpg 22g.png

23.jpeg 23.png 23g.jpg 23g.png

24.jpeg 24.png 24g.jpg 24g.png

25.jpeg 25.png 25g.jpg 25g.png

26.jpeg 26.png 26g.jpg 26g.png

27.jpeg 27.png 27g.jpg 27g.png A pleasant court (The Temple) illuminated by gas lamps (glaring, but not too strong). A beam from a skybeamer behind. Sky luminance from 0.10 cd/m2 to 0.05 cd/m2, terrain about 0.02 cd/m2.

28.jpeg 28.png 28g.jpg 28g.png Sky with Vega and Deneb within the top of the Northern Cross. Towards city centre, sky luminance is about 24 mcd/m2.

29.jpeg 29.png 29g.jpg 29g.png

30.jpeg 30.png 30g.jpg 30g.png

31.jpeg 31.png 31g.jpg 31g.png Sky with Andromeda, Great Square and Aries stars, away from city centre. Sky luminance about 20 mcd/m2

33.jpeg 33.png 33g.jpg 33g.png Sky with Perseus, two Andromeda and Aries stars and some high clouds; airplane at upper right. Clear sky luminance about 18 mcd/m2, clouds have 22 mcd/m2