SUN CALENDAR
An attempt to map the amount of sunlight in London, to know how grey can “grey weather” be. We are in the process of installing a light sensor on a server and having a more accurate picture. What’s below is a collection of morning pictures taken always with the same exposure parameters (1/60; f4.0; ISO200) and overwritten with the reading from an LDR connected to an Arduino. This is the table of a month (20 Jan 2010 – 20 Feb 2010).
20/02/10
11.11am 297
19/02/10
9.08 am 321
18/02/10
8.21am: 410
17/02/10
8.42am: 306
16/02/10
9.42am: 398 (and it’s miserable weather.. rainning…)
15/02/10
8.39am: 414
14/02/10
11.45am: 392
13/02/10
12.23pm: 302
12/02/10
9.29am: 412
11/02/10
7.57am: 432
8:23am: 385
8.37am: 375 (picture)
10/02/10
8.54am: 297
9/02/10
9.14am: 339
8/02/10
8.44am: 517
Trying methods to understand the composition of the light. The pictures below are superimposed with a picture of the RGB curve. I’m not sure we have achieved anything significant… Darker days have more volume on the left. Brighter days towards the right. Darker days have larger flat segments. The best picture has a better distributed curve.
7/02/10
10.41am: 414 (Berlin)
6/02/10
10.41am: 398
5/02/10
No reading… arriving to Berlin and going straight to Transmediale. I take a picture in the train station in the airport at around 12.30 pm.
4/02/10
8.35am: 564
3/02/10
8.50am: 391
2/02/10
8.44am: 587
1/02/10
8.53am: 406 (the sky is totally blue but from my window I can only get this poor readings!)
30/01/10
8.30: 409
8.57: 374 (picture)
29/01/10
9.14am: 443
28/01/10
8.41am: 457
27/01/10
9.54am: 299
26/01/10
9.26am: 334
This is a graph produced by Pachube of an hour of measurements from 9.40 to 10.40 am. A bright day…
11.16am. Quite bright but still a bit cloudy. Measurements:
- Sara’s window (SW): 227
- My window (NE): 290
12.47am. Sunny (winter sun, not very intense + very very thin clouds)
Sara’s window (SW): 140
My Window (NE): 296
25/01/10
8.34am: 726
24/01/10
10.30am: I take the picture but I don’t have the Arduino with me to take the measurement.
2.11pm: 395. It’s darker than it was when I took the picture.
23/01/10
10.30am: 479
22/01/10
8.25am: 770
9.02am: 602
21/01/2010
8.48am: 546
9.11am: 521
9.15am: 512
20/01/2010
Sorry for the silence. Me and Sotiris have been perfecting the technique of sun tracking. Now we are using an LDR and an Arduino board. It’s still not running 24h but I’m taking measurement every now and then. With regards to the pictures I was taking of the skies, I decided it might be smarter to fix the parameters of exposure so we get a significant range of light. Exposure will be 1/60; f = 4.0; ISO 200.
Today is one of the darkest days ever. The LDR gives us the following values (values range from 0 – absolute light – to 1023 – absolute darkness).
Today 9.30 (meter outside the window): 665
9.45am: 557
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The pictures below were not taken with consistent exposure parameters and therefore can’t really tell us much about the variation of light.
29/10/2009
Cloudy.
28/10/2009
Mainly cloudy, blue sky in the afternoon.
27/10/2009
Grey.
10.30am. Blue sky!
26/10/2009
Sunny.
25/10/2009
Sunny intervals.
We move the clock. Days are even shorter now.
24/10/2009
Grey.
23/10/2009
Sunny!
22/10/2009
Wake up. It’s sunny.
Go out… Sunny ‘intervals’.
At FF until it gets dark. :(
21/10/2009 GREY
At home. Light rain in the morning.
In the afternoon…
20/10/2009 GREY ALL DAY
19/10/2009 GREY AND OPENS UP
Woke up at 7am. Dark.
Left the house 8am. Grey.
After 5 saw blue sky and managed to take Sun_Reflection_II.
Earlier in October, Sun_Reflection_I
