| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| cfastie | "Dan, paste this embedding code into the note. We might have to adjust the height and width values. [open angle bracket]iframe src="http://www.giga..." | Read more » | about 11 years ago | |||
| cfastie | "Jeff, the critical angle seems to be the grating angle in relation to the light path from the slit. For 1000 lines/mm grating film, this angle is a..." | Read more » | about 11 years ago | |||
| cfastie | "That looks beautiful. Also very clever. Will there be any provision to alter the geometry among the slit, the grating and the camera lens? Assumi..." | Read more » | about 11 years ago | |||
| cfastie | "I guess that's 148 megapixels. So get a free account at gigapan.com, download the free uploader, upload your jpg, and click on embed to get the emb..." | Read more » | about 11 years ago | |||
| cfastie | "ICE is free and easy and worth having: http://research.microsoft.com/en-us/UM/redmond/groups/IVM/ICE/ You can get a free account at Photosynth: ht..." | Read more » | about 11 years ago | |||
| cfastie | "Dan, How many pixels does is have? If you cut it into three generously overlapping pieces, then stitch them back together in Microsoft ICE, you can..." | Read more » | about 11 years ago | |||
| cfastie | "Required viewing for Spectronic 20 owners: Thanks to Nadya for discovering this one. " | Read more » | about 11 years ago | |||
| cfastie | "Yes, now I have it. When the entrance slit is rotated the rectangular spectral image turns into a parallelogram. It seems to get compressed vertic..." | Read more » | about 11 years ago | |||
| cfastie | "Tom, The Jobin Yvon tutorial describes reflection gratings, and I don't know enough to apply those rules to our transmission grating setups. The ma..." | Read more » | about 11 years ago | |||
| cfastie | "Dan, I don't know what you mean by slit to grating angle. Angle g? Tom, I am reading now! " | Read more » | about 11 years ago | |||
| cfastie | "Jeff, Really good questions. I don’t think I can answer any of them from first principles. Focusing the image of the spectrum is one of the inscru..." | Read more » | about 11 years ago | |||
| cfastie | "Adam, You must be right that some protocols for identifying substances require knowledge of the absolute intensity of spectral peaks. I am not fam..." | Read more » | about 11 years ago | |||
| cfastie | "Adam, That's right, a narrower entrance slit allows emission or absorption lines to be resolved better. So you can know more precisely the wavelen..." | Read more » | over 11 years ago | |||
| cfastie | "Andres, I think when you do some things to a spectrum, like re-extract, rotate image, or set sample line, the calibration is reset to null. So it m..." | Read more » | over 11 years ago | |||
| cfastie | "Hi Jan, Thanks for this post. It is really good to see data on the effect of the blue LED. Your spectrograph makes it clear that most people will..." | Read more » | over 11 years ago | |||
| cfastie | "It looks like 3° of change in the angle is not enough, and maybe 6° is needed for center the visible spectrum in the photo image. But I am a little..." | Read more » | over 11 years ago | |||
| cfastie | "The only relevant waste stream I know of is under my desk where several one inch squares of the stuff are somewhere. I keep dropping them and litt..." | Read more » | over 11 years ago | |||
| cfastie | "Pat this is cool. Obviously there are no overhead utility lines in your neighborhood. Hooray for suburban planning. " | Read more » | over 11 years ago | |||
| cfastie | "Instructions for using the Public Lab spectrometers are here: http://publiclaboratory.org/wiki/spectral-workbench-usage The key instruction for yo..." | Read more » | over 11 years ago | |||
| cfastie | "Babu, You might be right that the blue channel is more sensitive to NIR, based on the fact that the healthy foliage in your super blue photo has a..." | Read more » | over 11 years ago | |||
| cfastie | "Babu, The new camera is going to be very fun to use. It would be interesting to see a histogram for each channel from an image like that one. We c..." | Read more » | over 11 years ago | |||
| cfastie | "Brent, It might be that you need to adjust the alignment of the camera. The relationship among the slit, the grating, and the camera is critical ..." | Read more » | over 11 years ago | |||
| cfastie | "Babu, Here is a paper about getting separate NIR and red bands by doing what Ned suggested – subtracting one band from another: http://cigr.ageng20..." | Read more » | over 11 years ago | |||
| cfastie | "Hi Babu, My limited experience with these techniques leads me to suggest that it will be quite difficult to separate the red and near infrared ban..." | Read more » | over 11 years ago |