| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| Tom_H | "maybe I have it now " | Read more » | about 11 years ago | |||
| Tom_H | "Your text to link...O.K. I am going to try to insert drawings from Picasa: it seems I haven't learned to do imbedding, but here is the link htt..." | Read more » | about 11 years ago | |||
| cfastie | "The Google group is completely separate from this web site, so the two places have somewhat independent conversations. I guess the Google group is ..." | Read more » | about 11 years ago | |||
| Tom_H | "Chris, I will work on doing an upload somehow. I have plots-spectrometry in my google groups, but I can't find these research notes there. " | Read more » | about 11 years ago | |||
| cfastie | "Tom, images would be very helpful (so my mind doesn't explode). If you upload images to a site like Flickr or Picasa you can grab the HTML embeddin..." | Read more » | about 11 years ago | |||
| Tom_H | "Hi straylight, You make some good points, and I think you need to think more about a couple of things. 1) Even with a slit small enough to produc..." | Read more » | about 11 years ago | |||
| straylight | "Chris, you said: "At certain grating angles, it is not possible to see a sharp image of the spectrum when the grating is too close to the slit. Bu..." | Read more » | about 11 years ago | |||
| Tom_H | "I think the reason that Chris has trouble getting good resolution at certain angles has to do with the eye's focusing mechanism, and the focus may ..." | Read more » | about 11 years ago | |||
| cfastie | "Stu, Thanks for the lesson! It’s really good to get a feeling for these concepts. I wish you had been my high school teacher. TomH sent me a spre..." | Read more » | about 11 years ago | |||
| straylight | "well done cfastie, thanks for taking the time to conduct some measurements. I've been pondering over the pattern and the angles for some time now. ..." | Read more » | about 11 years ago | |||
| straylight | "oh yeah, Love the lego optical bench and the discussion in the other research note. stu " | Read more » | about 11 years ago | |||
| cfastie | "I am glad you raised the question of how the distance to the slit could affect how much the light was bent when it hit the diffraction grating. Thi..." | Read more » | about 11 years ago | |||
| Tom_H | "What you are observing here may be related to what is referred to as the "blaze" angle of the grating. For actual diffraction gratings, the indivi..." | Read more » | about 11 years ago | |||
| Tom_H | "The basic grating equation works for transmission as well as reflection. The sign conventions can throw you though. One purpose of the collimatin..." | Read more » | about 11 years ago | |||
| liz | "This is amazing! I also like Dan Beavers graphic :) " | 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 | |||
| danbeavers | " I hope this illustrates what I mean. " | 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 | |||
| danbeavers | "Chris, I am referring to the rotational alignment between the slit axis and the grating's ruling. What is the effect when the angles are rotated? " | 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 | |||
| Tom_H | "Great job! An optical bench from Legos --- super! Yes there are a lot of variables at work here. If you want to bend your mind a bit, read some of..." | Read more » | about 11 years ago | |||
| danbeavers | "Great investigation! Another question is slit to grating angle. What effect does that have? What are the symptoms of misalignment? " | 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 | |||
| warren | "Oh, almost forgot my other question! Do the camera lens and aperture make any difference at all? You didn't use a camera for this... could you try ..." | Read more » | about 11 years ago |