| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| 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 | |||
| warren | "Thanks, Gwill -- good resource. Chris, I wanted to get some more clarity from @gretchengehrke on the mercury oxidation states in the comments of m..." | Read more » | about 9 years ago | |||
| Guillaume123 | "Chris, Have you ever looked at "The Elements Spectra"; it gives you numerical values of the peaks, you can get it from: www.infini-t.com or email..." | Read more » | about 9 years ago | |||
| warren | "Don't we have an ocean optics spectrum to source from too? I don't remember if we took a cfl spectrum with it, but we could maybe ask Mary to take ..." | Read more » | about 9 years ago | |||
| warren | "Oh, sorry, to be clear, i just need the wavelength values. " | Read more » | about 9 years ago | |||
| warren | "Hi Chris, for the upcoming "root mean square error" calibration "fitness" test, I want to sample not every single point, but all the peaks and trou..." | Read more » | about 9 years ago | |||
| warren | "Dave posted the code here, thanks! https://gist.github.com/Stoft1/2f3fd173f1ea3ccb2b45 " | Read more » | over 9 years ago | |||
| stoft | "Jeff, yes I think there were a couple attempts to 'correct for non-linearities' using polynomial curve-fit functions. They assumed there was some h..." | Read more » | almost 10 years ago | |||
| warren | "Hi, Dave - I recall that someone's posted Matlab code before for a non-linear calibration method. Do you have some code to share which we can port ..." | Read more » | almost 10 years ago | |||
| cfastie | "That would be very good news if the problem was lens distortion, because that can be corrected with a single click. I will look into that. The imag..." | Read more » | almost 12 years ago | |||
| Tom_H | "I am guessing that what you are seeing is due to lens distortions from your camera. If this is the case, each different camera will have a differe..." | Read more » | almost 12 years ago | |||
| straylight | "wow, what a useful research note, thanks for taking the time to post it and explain what you did. Interesting to be able to compare the ocean opti..." | Read more » | about 12 years ago | |||
| cfastie | "That's a challenge if smartphone cameras are not very sensitive to low light. More tests are called for, but I think the cheap diffraction grating..." | Read more » | about 12 years ago | |||
| warren | "I think maybe you mean 0.2mm and 0.4mm, mathew? Good to know, both of you -- i'm getting the desktop kit slits cut today!! Thanks. " | Read more » | about 12 years ago | |||
| mathew | "Chris-- When I was doing the spectrometer tests I found that 2mm was too dim to reliably read the spectra with a cell phone camera and settled on 4..." | Read more » | about 12 years ago | |||
| warren | "For the short term, it will prompt you to take a photo, and will allow you to upload it. Once we start on the native app, it will work just like th..." | Read more » | about 12 years ago | |||
| cfastie | "Alex - That's an good point that some smart phones do HDR. To improve the chances of great results, users of the smart phone spectrometer could tak..." | Read more » | about 12 years ago | |||
| warren | "I'm very impressed that the foldable spectrometer can get such good resolution. Partially, of course, that's the DSLR, but I'm glad that folks with..." | Read more » | about 12 years ago | |||
| cavazos | "Chris Thanks for sharing your views. I believe the exposure issue can be fixed by using High Dynamic Range or HDR technique. I'm not a photography..." | Read more » | about 12 years ago | |||
| cfastie | "Hi Alex, I haven't experimented much with webcams yet, so I don't know the answer. I do know that a narrow slit is critical for precisely identif..." | Read more » | about 12 years ago | |||
| cavazos | "Hi Chris, In your opinion, what single item improves most the results of the spectrometer? Better camera? The grating? The spectrometer case? In o..." | Read more » | about 12 years ago |