where to buy blue light meter online?
i want to by blue light meter online, so i can test the blue light from differnt light sources ?
@radiology_dr They are called spectrometers, and they show ALL wavelengths of light, even some UV and infrared (heat), and they are VERY VERY expensive. Some start at around $2000.
If you want to see some color spectrum charts, see the fluxometer: https://fluxometer.com/
@radiology_dr I have an idea--you can use a blue shirt, and how blue it looks (versus more green or even greyish) is how much blue there is an a light source.
This is a neat idea, however there's are a TON of different ways to make an object appear blue. Rather, you can buy technical filters if you want to focus on a specific wavelength of light.
You can buy a sheet of each color for less than $10 through barbizon.
Then you can apply this filter over a standard light meter and measure away. Be sure to also capture the photopic lux as well. You want to make sure you're measuring blue content per lumen (Visible light).
The cheapest way I know is:
- Buy some blue "pool cue chalk"
- Put your blue chalk and white chalk in a box you can carry around
- Take a picture of it when you want to measure something
Do this for daylight to calibrate your chalk (you'll need an imaging app that lets you get linear pixel values, like Photoshop in 32-bit mode).
Then, to test another source, do this again, and get a ratio.
We measured some chalk with a spectrometer and its reflectance spectrum peaks at 470nm.
70 cents for a blue light meter!
@herf It helps to rub the chalk on a rough surface like concrete or sandpaper the first time to smooth it out!