| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| 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 | |||
| 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 | |||
| stoft | "@Ag8n true, calibrating before a measurement (or series of) helps assure the measurement data is referenced. As per wavelength references, while t..." | Read more » | about 6 years ago | |||
| stoft | "I suspect there are two issues here: 1) the software interface and 2) mechanical instability. On #1, I believe the web-based software always needs ..." | Read more » | about 6 years ago | |||
| stoft | "While one could construct two, parallel slits, no, that would not 'enhance resolution. A single slit is many, many wavelengths 'wide'. Assuming ide..." | Read more » | about 6 years ago | |||
| stoft | "Color temperature is the perceived 'color' of light emitted from an ideal black-body radiator due to it's physical temperature in deg-K. An ideal b..." | Read more » | about 6 years ago | |||
| stoft | "Questions are good ;-) Reading between the lines of your description, the "blank" is the Transmission Reference (i.e. the clear container with onl..." | Read more » | about 6 years ago | |||
| stoft | "@warren - Looks like another spammer ...... " | | over 6 years ago | |||
| stoft | "Great! 1) I'd also suggest using stiff cardboard, Exacto knife, hot-melt glue (or fast-set 'yellow' wood glue 2) use double-stick for the DVD att..." | Read more » | over 6 years ago | |||
| stoft | "You could buy a webcam from Amazon, use a spare DVD some razor blades, black paper, double-stick tape and build one for about $50 (most of the expe..." | Read more » | over 6 years ago | |||
| stoft | "Without a "reference standard" the measurements will all be relative; not absolute (like ppm [parts per mission]). So, the relative concentration w..." | Read more » | over 6 years ago | |||
| stoft | "The posted graphs are, mostly, just individual experimental plots. Assuming 1) working spectrometer, 2) has been wavelength-calibrated using a CFL ..." | Read more » | over 6 years ago | |||
| stoft | "Nice graphics. Yes, white LEDs are not broad spectrum. If it's of any help, I set (Matlab code) the ELP camera to: Manual Exposure, Exposure=-3 (-1..." | Read more » | over 6 years ago | |||
| stoft | "The vertical scale is purely relative, representing the combined RGB responses where 100% represents the clipping level for any of the RGB channels..." | Read more » | over 6 years ago | |||
| stoft | "Ah, good. Glad you could view the additional data and figured it out. " | Read more » | over 6 years ago | |||
| stoft | "Yes, clearly all but the last image shows compression in the Green (and Red though less). Because the process of spectral data from a webcam does n..." | Read more » | over 6 years ago | |||
| stoft | "The camera's I've used seem different in this effect but you might try to hunt down the technical data sheets from the Mfg -- sometimes they have a..." | Read more » | over 6 years ago | |||
| stoft | "@Tehnicni, I'd agree that any detector-specific non-linearity is likely very small compared with the effect you've presented. I'd guess the more li..." | Read more » | over 6 years ago | |||
| stoft | "IMHO, the 2-angle configuration was simply derived through mechanical tinkering. It seemed to work and so was subsequently measured and documented ..." | Read more » | almost 7 years ago | |||
| stoft | "There's still some clipping (source light intensity too high) so a comparison, using a cardboard mask (with a small hole in it), between the two bu..." | Read more » | over 7 years ago | |||
| stoft | "No I don't think it is just inherent in the camera. The blue led has a fairly narrow spectrum (say 25nm at most) so producing a 150nm 'spread' woul..." | Read more » | over 7 years ago | |||
| stoft | "I note that 1) your spectrum does "fit" though it is 2) "offset" a bit from center which is likely related to the angle. (Just to identify what is ..." | Read more » | over 7 years ago | |||
| stoft | "The angle is a function of (mathematical) of the detectable wavelength range and the diffraction grating (DVD) line spacing. My calculations and my..." | Read more » | over 7 years ago | |||
| stoft | "@stef, thanks for the curve data. While the data is useful for comparison with relative sensitivity curves of other cameras, the data, unfortunatel..." | Read more » | over 7 years ago |