| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| stoft | "Thanks; interesting thoughts. Yes, digital cameras can have white balance settings which create a general shift in the RGB output ratios, but the S..." | Read more » | about 9 years ago | |||
| MrBumper | "I'm wondering if you took any account of the web camera settings - in particular colour temperature / white balance. This has quite a large effect ..." | Read more » | about 9 years ago | |||
| mathew | "my experience has been similar-- just because a very bright source in the 800-1000nm range can be detected doesn't mean that we can trust the sensi..." | Read more » | about 9 years ago | |||
| stoft | "Thanks. Yes, the camera has virtually no relative sensitivity outside 400-700nm. This does need to be differentiated from observing a bright source..." | Read more » | about 9 years ago | |||
| mathew | "This is awesome, Dave! The noise above 700 and below 400nm is substantial, but I think that just defines the usable range of the spectrometer. @w..." | Read more » | about 9 years ago | |||
| mathew | "Cool! added it here: http://publiclab.org/wiki/spectrometer-history " | Read more » | almost 10 years ago | |||
| warren | "Linked to from http://publiclab.org/wiki/oil-testing-kit#Challenges " | Read more » | almost 10 years ago | |||
| warren | "@mathew - just dug up this old note, which shows a method for equalizing area. I'd love to find more literature on the subject, but it's worth a tr..." | Read more » | almost 10 years ago | |||
| warren | "Exciting! " | Read more » | about 10 years ago | |||
| sekjal | "Can't wait to get my hands on the updated version and build some sweet Lego cases/containers/contraptions! " | Read more » | about 10 years ago | |||
| donblair | "And here's a nice way of doing color mixing using a ping pong ball as a diffuser: https://teachers.web.cern.ch/teachers/archiv/hst2005/part_sessio..." | Read more » | about 10 years ago | |||
| warren | "I think if we do something with a few more lines, as you say, we can try it out. Say, 75-50-25-0-25-50-75, each band being about a 1/4" wide. If yo..." | Read more » | almost 11 years ago | |||
| stoft | "Yes, I could print a couple sheets but it would be best to decide on the best pattern and density if you're looking to send something along the lin..." | Read more » | almost 11 years ago | |||
| warren | "Aha! http://www.amazon.com/3M-3700-Color-Laser-Transparency/dp/B00004TS5M/ I'll order this now; maybe drying won't be a problem with a laser print..." | Read more » | almost 11 years ago | |||
| warren | "I actually don't have an inkjet printer; would you be at all interested in printing a few sheets of this and mailing it to me? I could then cut it ..." | Read more » | almost 11 years ago | |||
| stoft | "Yes, I ink-jet printed on 'Grafix' transparency film (not the adhesive version)-- it's available on-line via Amazon. It's reasonably stiff in small..." | Read more » | almost 11 years ago | |||
| warren | "Thinking about how to do this well... did you print on a laserprinter? Can you run transparency through one of those? Would inkjet work, or would i..." | Read more » | almost 11 years ago | |||
| stoft | "I see your point. I just wonder about having only a single attenuation step which could make it difficult to find the best level; a case of too lit..." | Read more » | almost 11 years ago | |||
| warren | "I actually think there's an advantage to stepped grading, because a) it's easier to pick out the pattern -- like a barcode -- vs. continuous chang..." | Read more » | almost 11 years ago | |||
| stoft | "Ok, interesting idea. The extension to this is a continuously variable attenuator and let the detection algorithm pick the line w/max signal but w/..." | Read more » | almost 11 years ago | |||
| warren | "users would naturally just pick the middle I guess I'm suggesting that with a 50/0/50 attenuator, although users may pick the middle naturally (as..." | Read more » | almost 11 years ago | |||
| stoft | "I'd agree that giving more visibility the the clipping issue would be good and this is a simple, cheap tool. However, I don't quite follow your 2-s..." | Read more » | almost 11 years ago | |||
| warren | "Hi, Dave - I was thinking that given the propensity to take clipped data in almost all devices out there, what if we printed a whole bunch of these..." | Read more » | almost 11 years ago | |||
| stoft | "Jeff, Thanks. I've just posted an addendum at the end of this research note to add some plots specifically looking for linearity. I believe the ima..." | Read more » | about 11 years ago |