Wednesday 29 July 2015

Belichting

De waarde “EV” heeft dus verschillende betekenissen naargelang de context:
  • een absolute waarde (11.5EV, zie foto van de lichtmeter
  • een relatieve waarde (+1EV, foto “één stop” overbelichten, zie hieronder) 
  • een dynamisch bereik (bijvoorbeeld 8EV, zie hierboven) 
Fototoestellen kunnen de helderheid instellen (bewust onder- of overbelichten). Daarbij kan gewerkt worden in stappen van 1/3EV of 1/2EV (een derde of een halve stop). Stappen van 1/2EV worden het vaakst gebruikt omdat er standaard-waarden gebruikt worden (sluitertijden van 1/30, 1/45, 1/60, 1/90, 1/125 enz en openingen van ƒ/2.0, ƒ/2.4, ƒ/2.8, ƒ/3.5, ƒ/4 enz), maar met kleinere stappen kan de belichting nauwkeuriger ingesteld worden.

De nulwaarde (EV=0) komt overeen met een sluitertijd van 1 seconde en een lensopening van ƒ/1 bij ISO 100. Of een sluitertijd van 4 seconden bij ƒ/2. Sommige belichtingsmeters kunnen de gemeten waarde ook in lux weergeven, deze eenheid wordt in de natuurkunde gebruikt.

EVLuxEVLuxEVLuxEVLux
0.02.55.08010.0260015.082k
0.53.55.511010.5360015.5120k
1.056.016011.0510016.0160k
1.57.16.523011.5720016.5230k
2.0107.032012.010k17.0330k
2.5147.545012.514k17.5460k
3.0208.064013.020k18.0660k
3.5288.591013.529k18.5930k
4.0409.0130014.041k19.01.3M
4.5579.5180014.558k19.51.9M
Deze omrekeningstabel is enkel geldig als ISO=100 ingesteld staat!
NOTE:
Als ik de metingen doe met twee verschillende apps:
Pocket Light Meter (EV100) en de Megaman App (Lux) komen de waarden ongeveer overeen met bovenstaande tabel

Als je lichtmeter bijvoorbeeld op 200 ISO staat, moet je gewoon 1 EV aftrekken (gemeten = 8.5 --> effektief 7.5)
  • Helderheid in huis: ongeveer 50 lux, 
  • helderheid in een kantoor: 500 lux (europese normen), 
  • helderheid om in de beste omstandigheden foto's te kunnen nemen: 2500 lux (10EV). 
  • Vanaf 15EV (ongeveer 100.000 lux) hebben de modellen het lastig om hun ogen goed open te houden bij portretfotografie. 

Bij het verhogen van de belichtingswaarde stijgt ook het contrast (verschillen tussen donkere en heldere delen van het beeld of dynamisch bereik). Vanaf 15 EV is het contrast meestal zo sterk dat een fototoestel niet meer mee kan. Je zal hulpmiddelen moeten gebruiken om het licht te temperen: werken in de schaduw, zonnetent gebruiken, enz.

Bron: http://pics.idemdito.org/fysica/ev.htm

Friday 24 July 2015

Concert Riverside (De Boerderij, Zoetermeer)

fryday Jul 24, 2015

20:30h  De Boerderij

The Polish progressive rock band Riverside needs no long introduction. The band was founded in 2001 by Mariusz Duda and is now among the top contemporary prog scene. Riverside is renowned for their unique blend of dynamic rock and beautiful melodies. Their music contains elements reminiscent of Pink Floyd, Marillion, Porcupine Tree, Opeth, Dream Theater, but the band manages to retain its identity. Their latest album 'Shrine Of New Generation Slaves' (2013) is their most successful album until now and let hear the evolution of Riverside. The release of their new (sixth) studio album 'Love, Fear and the Time Machine' is scheduled in early September.

Sunday 19 July 2015

Regenton

Voor het afdakje achterin de tuin (waar de motor onder staat) heb ik een 100mm goot gemonteerd met een afvoerbuis 80mm naar de stoep buiten de poort.
Tussen deze buis heb ik een vulautomaat voor de 185 liter regenton gezet.
De regenton (€50 Voertonnen.nl) heb ik op een 35 cm verhoging staan van grindtegels. In de holle deksel zit een filter voor zand e.d. Het 40mm vulpijpje kan ik in de winter met een dop afsluiten.


Wednesday 15 July 2015

pH en EC - meten is weten

Ordered at AliExpress a digital pH meter (€6,07) en TDS meter (€3,41). The button cells (3x for PH meter, 2x for TDS meter) AG13 (12st. €0,90) are separate ordered (12p €0,90).


The PH-meter do I clean afterwards with distilled water and dry the sensor gently with a paper towel.
Calibrate with pH buffer powder pH 4.00 and pH 6.86 (€ 0.64) and measure any manually Litmus paper strips (litmus test for color) 80st. € 0.35.
For the TDS value to convert to EC value in mS / cm, I share the ppm value by a factor of 640:


Testmeting 19-6-'15:

Temp ℃ 
   pH   
TDS ppm
EC mS/cm
Distilled water
22,7
7,1
43
0,07
Tap water
21,7
7,9
140
0,22
Tap water + nutrition
21,5
7,1
900
1,40
Rain water
20,2
7,2
48
0,08
Rain  + nutrition
20,2
6,8
690
1,08


Temperature correction:
Distilled water: 20℃ - pH 7,08
Distilled water: 25℃ - pH 7,00

The ideal pH for plants is from 5.8 to 6.5. Making more acidic may best with natural vinegar (or nitric N). If the plants in blooming with phosphoric acid P (PH-min Canna Bloom), you only need a little.



Soil PH-Moisture-Light tester $3.30


Wednesday 8 July 2015

Mini Microscope 60x

Super Mini 60X Microscope
Light: 2x Led bright white, 1x Led UV (for valuta)
Battery: 3 * LR1130
Dimensions: 3.8x3.6x1.8 cm
Gewicht: 18 gr
Price: DealExtreme $3.50



Thursday 2 July 2015

Parrot 'Flower Power'

With Flower Power, Anyone Can Have A Green Thumb
Parrot Flower Power is a sensor that can be "planted" close to a plant, indoors or outdoors, in a pot or in open ground. It precisely measures, in real time, the parameters that are crucial for the growth and good health of plants:
Soil moisture, fertilizer, ambient temperature, and light intensity.
Plants have vital needs, and Parrot Flower Power uses advanced sensor technologies to monitor the plants' welfare through a range of parameters. Using the data gathered every 15 minutes by the four sensors, users are able to understand the exact requirements of their plants. The materials chosen for manufacturing the Flower Power ensure the product is watertight and robust. The Parrot Flower Power can be used both inside and outside (from -10 °C to 55° C). Waterproof, it can withstand watering, rain, and liquid fertilizer. Put it in the ground or in a pot and monitor the changes in your plants and garden.

Bluetooth, smart and realtime monitoring of multiple plants.
The data retrieved by the Parrot Flower Power is sent to your Smartphone or Tablet using Bluetooth low energy technology, allowing it to communicate with Bluetooth Smart Ready devices. Bluetooth Low Energy is a wireless technological standard which consumes very little energy. When you are near your Flower Power, you can use Live mode to check the light intensity, ambient temperature, and soil humidity. Every 15 minutes Flower Power measures four data sources and stores the data in its memory. Every two hours Flower Power sends data to your Smartphone via Bluetooth Low Energy. If you are not within Bluetooth range, it keeps the data in its memory until you are back within range (data kept for up to 80 days). Alerts are sent to your Smartphone each time one of your plants needs attention. There is no need to be near your Flower Power to get the notifications. A Parrot Flower Power can monitor several plants in the same pot, in a planter or on a small plot of land if the conditions of watering, soil drainage, and exposure to the sun and wind are uniform.


A Dedicated App
Download the free Parrot Flower Power App on your Smartphone/Tablet. The application will then connect your Flower Power to the Parrot Cloud (via 3G/4G or Wi-Fi), where the data is analyzed. After the data is analyzed, you will receive an alert in real time when one of your plants has special water, fertilizer, light, or temperature needs. Follow the changes in your garden directly or simply consult Parrot's vast but easy to use database. Using the application, users can select their plants from the database in the Parrot Cloud, which has been developed by botanists. More than 7,000 varieties are listed and custom advice is given on maintaining each plant.

(5) Cannabis Hybrids: G13, Jack Herer, Lowryder, Morning Star,White Widow
(4) Cannabis Indica: Blue Rhino, Blueberry, Bubba Kush, Nothern Lights
(1) Cannabis Sativa: Sour Diesel

Price: €44-49
Links: ParrotMyFlowerPower



More Details:

Air Temperature

  • Range: -5°C to +55°C
  • Accuracy: +/- 1.5°C
The range of temperature that is generally comfortable for most plants is between 10-32°C (50-80°F). Various stresses may affect plants outside this range, but it is highly plant specific.


Light
  • Range: 0.13 to 104 (mole x m-2 x d-1) 
  • Accuracy: +/- 15% 
The light sensor is calibrated to measure Photosynthetically Active Radiation (PAR), defined as light in the wavelength between 400 - 700nm (the visible spectrum).

Soil Moisture

  • Range: 0 to 50 (%) 
  • Accuracy: +/-3 
The typical soil moisture range is between 8 (very dry) to 45 (saturated). The soil moisture will read 0 when in air. Generally, most plants require watering when the soil moisture is in the range of 12 to 18. If the soil moisture stays >40 for too long, this may be harmful to some plants (overwatering promotes the growth of pathogens in the soil, and plants require oxygen at their roots for good health). Specific watering and overwatering thresholds depend on the plant type. Due to variations in soil composition, texture, compaction, and other factors, variation of the soil moisture readings can be greater in practice than the accuracy of the sensor suggests. To reduce these variations, always water around the sensor when it is first inserted into the soil to remove air gaps. When container gardening, always use a container with holes at the bottom for good drainage.

Fertilizer

  • Range: 0 to 10 (mS/cm) 
  • Accuracy: +/-20% 
The typical range for fertilizer in horticultural applications is 0 to 4 mS/cm. Generally, fertilizer >1 is low, fertilizer in the range of 1 - 3 is a good range, above 3 is high, and above 4 may to too high. Fertilizer usage and sensitivity is plant specific. After application of liquid fertilizer based on the manufacturer recommendation for your plant, you should immediately notice on the sensor that fertilizer is in a good range. When using compost or slow-release fertilizers, it can take a longer time for the fertilizer to register on the sensor. Due to uneven distribution of fertilizers in soils, variation on fertilizer readings can be greater in practice than the accuracy of the sensor suggests. To reduce these variations, always water your plant thoroughly -- this gives fertilizer the best chance to evenly distribute throughout the soil.