Calculating distance between lux meter and light source

AI Thread Summary
Calculating the distance between a light source and a lux meter can be approached using the inverse square law (ISL), which states that lux equals luminous flux divided by the square of the distance. However, the effectiveness of ISL may vary based on the light source's characteristics, such as its area or if it is a laser, which can complicate the measurement. Experimental data is essential to determine the distance at which ISL accurately applies. It is recommended to conduct experiments to identify the threshold distance for reliable results. Understanding these factors is crucial for accurate distance calculations in lighting experiments.
san-yas
Messages
1
Reaction score
0
I am currently performing some experiments to calculate the distance between a light source and a lux meter where the light source points directly towards the lux meter.
Is it possible to calculate the exact distance between the light source and the lux meter given that we have a lux value (through the lux meter) and the luminosity flux (through the information given by the light source manufacturer)? or is the inverse square law (lux=lm/d^2) subjected to particular conditions?
 
Science news on Phys.org
Welcome to PF.

It seems like the inverse square law should work for this. What have you seen in your experimental data so far?
 
san-yas said:
a light source
If the source has a significant area then ISL will stop working close up. Also, if the source is a laser, you will have a problem because the effective position of the source can be may metres behind the front (multiple mirror images, as with an infinity mirror) and the r in 1/r2 would need to be corrected for. ISL is fine for stars and planets but the Moon and Sun are very much distributed sources.

I would be inclined to do the experiment first and find what distance the ISL begins to work for.
 
Thread 'A quartet of epi-illumination methods'

Thread 'A quartet of epi-illumination methods'

Well, it took almost 20 years (!!!), but I finally obtained a set of epi-phase microscope objectives (Zeiss). The principles of epi-phase contrast is nearly identical to transillumination phase contrast, but the phase ring is a 1/8 wave retarder rather than a 1/4 wave retarder (because with epi-illumination, the light passes through the ring twice). This method was popular only for a very short period of time before epi-DIC (differential interference contrast) became widely available. So...
View full post »

Thread 'Effective absorption coefficient of gold nanoparticles'

I am currently undertaking a research internship where I am modelling the heating of silicon wafers with a 515 nm femtosecond laser. In order to increase the absorption of the laser into the oxide layer on top of the wafer it was suggested we use gold nanoparticles. I was tasked with modelling the optical properties of a 5nm gold nanoparticle, in particular the absorption cross section, using COMSOL Multiphysics. My model seems to be getting correct values for the absorption coefficient and...
View full post »

Similar threads

I Lux-meter, candelas or lux, measuring nits in practice
Replies
2
Views
5K
Struggling with light calculations (incident power output)
Replies
2
Views
2K
Furthest distance a light source can be seen
Replies
8
Views
14K
Converting Volt to Lux using a solarimeter
Replies
1
Views
5K
Converting radiometric units (W/m^2) to photometric units (Lux)
Replies
1
Views
8K
Luminance and illuminance of multiple point light sources
Replies
5
Views
5K
I I'm calculating more energy out than I put in
3
Replies
138
Views
7K
Intensity of Stars and the Inverse Square Law Problem
Replies
10
Views
3K
I Correlation between a Star's Luminosity and Distance?
Replies
10
Views
3K
B The distance to the nearest identical Hubble volume in light years?
2
Replies
50
Views
5K

Hot Threads

Recent Insights

Back
Top