Digital Cameras Lumens
Converting F- stop and Exposure to Lumens or Footcandles?
I have a digital camera, and I’m trying to figure out the number of lumens falling on a given area. I’m taking a light reading on a 12″ by 12″ square of white paper at iso 100, I get 1/160 at f2.8 anybody have any idea how to figure out the lumber of lumen or foot-candles? even calculating lux this way would be helpfull.
Thanks
believe this can be figured out, use the equation or the table on this page to to figure out the Exposure Value of a one square foot paper.
http://en.wikipedia.org/wiki/Exposure_value
you can then convert that value to lux here
http://www.intl-lighttech.com/library/calculators/evluxconvert
then convert that to foot candles or lumens here
http://www.unitconversion.org/unit_converter/illumination.html
You should have enough information to do this. I would suggest calculating the Exposure Value you have using:
http://en.wikipedia.org/wiki/Exposure_value
which is about 10.5 Ev for your case. This looks to be about 200ish cd/m^2, assuming certain calibration coefficients. That wikipedia page has more information.
Lumens Ladibug DC-120 with Wireless Adapter
|
|
Fenix E05 R2 Flashlight $19.51 Lightweight and compact, the Fenix E05 R2 portable, high-intensity flood beam flashlight is an ideal choice for everyday tasks. The portable E05 flashlight is small enough to fit comfortably in the palm of your hand. The E05 measures a mere 0.56 inches in diameter and 2.53 inches long–small enough to fit in your pocket, handbag, and just about anywhere else. The Cree XP-E bulb and mini lens, m… |
|
|
Fenix LD20 180 Lumen LED Flashlight $53.44 The Fenix LD20 LED flashlight is a digitally regulated and digitally controlled pocket-sized LED flashlight offering two output modes to maximize operational life and light output. The light features a virtually indestructible, microprocessor-controlled, CREE light emitting diode (LED) that has no filament to burn out or break that offers a reach of up to 135 meters. The small but mighty light can… |
|
|
Fenix PD32 Compact 315 Lumen LED Flashlight $67.95 The Fenix PD32 is the ultimate in high intensity flashlights! Compact small size that is perfect for outdoor use! Friendly user interface with side switch for selecting a brightness level. Features a hidden SOS function. Easy and convenient to carry with the added belt clip. Constructed of durable aircraft-grade aluminum with premium Type III hard-anodized anti-abrasive finish. Also has a toughene… |
|
|
ALZO Digital Full Spectrum Light Bulb – ALZO 45W Photo CFL 5500K 91 CRI, Daylight balanced, pure white light, 2800 Lumens, Case of 4 Case of 4 full spectrum light bulbs for daylight balanced lighting, energy star compliant, long-lasting at cir. 10,000 hours with 2800 Lumens output; low energy consumption, good for treating S.A.D. (Seasonal Affective Disorder), photo studio lights, or starting plant growth. These are Compact Fluorescent Light (CFL) bulbs. Fits all medium-base E27/E26 sockets, but this is a large bulb that might … |