| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| arun | " hi!! " | Read more » | over 5 years ago | |||
| cfastie | "Blueish photos result when the blue channel is brighter than the other channels. Reddish or orangeish photos result when the red channel is brighte..." | Read more » | about 6 years ago | |||
| cfastie | "The blue filters used block red light, so the red channel records a lot of NIR, so NGB. The red filters used block blue light, so the blue channel ..." | Read more » | about 6 years ago | |||
| stoft | "Pollution comes in many forms and many of the worst contaminants will not alter the appearance so visible light spectrometers (i.e. PLab types) wil..." | Read more » | about 6 years ago | |||
| Ag8n | "We always went with the longest path length. The visual test was done with 50 cm color comparison tubes. Very long for visual. Maybe you could d..." | Read more » | about 6 years ago | |||
| amirberAgain | "Be careful! light in the 450-480nm range (royal blue) is dangerous to unprotected eyes! 430 is not as bad but be aware! http://www.cree.com/led-com..." | Read more » | about 6 years ago | |||
| amirberAgain | "Can you measure pure water? Probably so! While largely transparent in the visible water absorb in the 700-850nm range, note that to image in that r..." | Read more » | about 6 years ago | |||
| thangvu | "I have no solution for multi-wavelength source like a spectrometer. I will try with another wavelength. " | Read more » | about 6 years ago | |||
| thangvu | "Thanks for your answer, I have the standard solution of 5-10-20..70 pt / cb (I borrowed), according to the standard method, when measured at 430nm,..." | Read more » | about 6 years ago | |||
| Ag8n | "Do you know what APHA values you will be observing? I was typically observing values under 25. And yes, a florescent light was very helpful again..." | Read more » | about 6 years ago | |||
| Ag8n | "If you used the right lamp, you would be ok. You need to use a broadband source, as stoft noted. " | Read more » | about 6 years ago | |||
| thangvu | "My idea is to use a 430nm wavelength to measure the color of the water, so, I use a 430nm (+ - 10nm) led as the source, but the 430nm led seems to ..." | Read more » | about 6 years ago | |||
| thangvu | "sorry for saying it is unclear, with wastewater, the color of the water partly assesses the level of water pollution. " | Read more » | about 6 years ago | |||
| stoft | "Depending on what information is needed from the spectrum (i.e. like the entire available spectrum, using a CLF will not be useful. A broadband sou..." | Read more » | about 6 years ago | |||
| thangvu | "Thanks for your helpful answers " | Read more » | about 6 years ago | |||
| Ag8n | "Try to avoid using blue water solutions, at least without doing some testing. The compact florescent lamps (CFL) loose intensity at the blue and o..." | Read more » | about 6 years ago | |||
| Ag8n | "Yes, it can. You need to go to the spectrometer page for more information. It will show how to set up cuvette s to hold water and what to use as ..." | Read more » | about 6 years ago | |||
| briandegger | "Maybe colour of liquid compared to distilled water/plain iron water. Qn example: Dissolved tannins give water a brown hue. " | Read more » | about 6 years ago | |||
| stoft | "Since H2O is a colorless fluid, 'color' appears not to be the correct intent of the question. The author would need to clarify the objective. " | Read more » | about 6 years ago | |||
| viechdokter | "@warren: I just had a look at an old spectrum CSV file of yours (3 years ago): https://spectralworkbench.org/spectrums/481 There it was unscaled ..." | Read more » | about 8 years ago | |||
| warren | "I went ahead and created a specific issue for native 8-bit storage: https://github.com/publiclab/spectral-workbench.js/issues/18 As well as outlin..." | Read more » | about 8 years ago | |||
| viechdokter | "Talking about hung-up scripts, it often is a pain in the neck to login to SBW. "Do you trust this site with your identity?" "Yes" "You must login t..." | Read more » | about 8 years ago | |||
| stoft | "It's ok to have a 'scaled' data file -- but ONLY if that file is clearly identified as such ... like /SpectrumData-SCALED_20160420.csv or /Spectru..." | Read more » | about 8 years ago | |||
| warren | "Hi, all -- 2.55 is definitely related to the 0-255 value. The code that generates the CSV is here: https://github.com/publiclab/spectral-workbench..." | Read more » | about 8 years ago |