| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| warren | "Oh thanks! I believe, but Chris may correct me, that it'd be sufficient to measure a cold long tube fluorescent lamp and compare it to pretty much ..." | Read more » | about 8 years ago | |||
| zega | "@warren , @cfastie I see i'm kinda late to the party, i can offer source verification (you can ship CFL source to me) with 3rd party device, Ocean..." | Read more » | about 8 years ago | |||
| warren | "I'm also looking for a better photo of a Desktop Spectrometry Starter Kit pointed at a CFL bulb, so if you have one please help me improve this post! " | Read more » | about 8 years ago | |||
| cfastie | "Correction: When I calibrate Corrected Snowy CFL (with itself), I can get a Fit as good as 5. But the two spectral images are not well aligned when..." | Read more » | almost 9 years ago | |||
| cfastie | "Ah, set as in SW set! Here is one with CFL spectra from you, me, stoft, and spectra4cps: https://spectralworkbench.org/sets/3165. All of these sho..." | Read more » | almost 9 years ago | |||
| warren | "Oh, just the spectra you're looking at to reach those conclusions. Sorry to mix vocab :-) " | Read more » | almost 9 years ago | |||
| cfastie | "What do you mean by references? " | Read more » | almost 9 years ago | |||
| warren | "Could you make a set of good double green line references to look at? " | Read more » | almost 9 years ago | |||
| warren | "There are a few places where we do math -- like convert from 0-255 to 0.000-1.000, and when repeated over many pixels, its possible that there are ..." | Read more » | almost 9 years ago | |||
| cfastie | "Jeff, I made a corrected (ideal) version of the Snowy Sky CFL spectral image when we were working through this in October. This is the basis for t..." | Read more » | almost 9 years ago | |||
| warren | "Hi, Chris - because we used lots of peaks to determine "fitness", we'd need all of the following nanometer positions plus their intensity (0-255): ..." | Read more » | almost 9 years ago | |||
| cfastie | "Jeff, are these the specs for the image you need for the reference spectrum: 1390 px wide with the blue 436 peak at 211 pixels from left, and the g..." | Read more » | almost 9 years ago | |||
| liz | "Great detective work @warren and @cfastie! " | Read more » | almost 9 years ago | |||
| warren | "Well, both images were taken from the same device within about 20 minutes, so you can check their images against one another even if they're not ac..." | Read more » | almost 9 years ago | |||
| cfastie | "That's some excellent detective work. We know there is mercury in all fluorescent lamps, so all the big mercury peaks should be present in all good..." | Read more » | almost 9 years ago | |||
| warren | "I added an update about suitability of long-tube fluorescent bulbs (non CFLs) for calibration which should be interesting to @liz and maybe @cfasti..." | Read more » | almost 9 years ago | |||
| warren | "Hmm. So I'm wondering if part of the fit problem is because we're simply comparing intensity at the 14 points and 13 troughs. Take this example: ..." | Read more » | about 9 years ago | |||
| warren | "Oops, meant to share links to my tests -- here's the one I used the new calibration system on, and listed 3 approximate errors for: https://spectra..." | Read more » | about 9 years ago | |||
| warren | "Hmm. I guess there are pros and cons to each approach. I agree that the 546 line doesn't result in a great linear calibration -- some end up about..." | Read more » | about 9 years ago | |||
| cfastie | "If the original Snowy Sky CFL is calibrated by pinning down the 436 nm and 546 nm peaks (using a macro) it looks like this: Most of the peaks do..." | Read more » | about 9 years ago | |||
| warren | "Would you be willing to try a recalibration using the 436/546 lines as a starting point? Would that be useful as a point of comparison? Also - I b..." | Read more » | about 9 years ago | |||
| cfastie | "That's a very important observation. Had I originally calibrated this spectrum on the 436 line and the 611 line (instead of 405 and 650), all the o..." | Read more » | about 9 years ago | |||
| warren | "If it's helpful, we can probably ask some of the OTK beta participants for one, since a couple have access to lab spectrometers. In your image/ima..." | Read more » | about 9 years ago | |||
| cfastie | "Hi Gwill, there do seem to be a lot of terbium peaks. I have not yet figured out how to know which of those peaks are expected in the light from a ..." | Read more » | about 9 years ago |