| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| cfastie | "I was assuming that the best way to preserve image quality when removing a glass filter would be to replace it with another glass filter. Plastic, ..." | Read more » | about 11 years ago | |||
| warren | "Very interesting line of inquiry. I've always been a bit confused about the role of the filter material itself in focus -- my assumption has been t..." | Read more » | about 11 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 » | over 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 » | over 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 » | over 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 » | over 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 » | over 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 » | over 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 » | over 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 » | over 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 » | over 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 » | over 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 » | over 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 » | over 11 years ago | |||
| mathew | "Dave, I bet quite a few folks in our community have Matlab, and it would be nice if they could replicate your experiments using your setup. Its ok..." | Read more » | over 11 years ago | |||
| stoft | "Stu, thanks. Yes, there's still much to be understood about the performance limitations. Jeff, the app is in matlab though it could probably be co..." | Read more » | over 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 » | over 11 years ago | |||
| warren | "Hi, Dave - very interesting... is this fairly related then to the suggestion of an "HDR" neutral density filter where we could get 0/25/50/75/100% ..." | Read more » | over 11 years ago | |||
| warren | "Hi, Dave - i'm very curious about the "app" you built - what was it in? Can you share it, or are you interested in open sourcing it? I'd love to tr..." | Read more » | over 11 years ago | |||
| straylight | "nice work Dave, very impressive. Some excellent diagrams and graphs. I think that a lot of work that we might do with the spectroscope will be wor..." | Read more » | over 11 years ago | |||
| stoft | "Yes, a large DOF can mean a less precise focus adjustment requirement, but near "infinity" the webcam just seemed out of focus over a wide DOF. Tha..." | Read more » | over 11 years ago | |||
| warren | "Hi, Dave - a few thoughts -- the DOF is high so this is very hard to do with any accuracy I've taken this as a very good thing -- as in, the larg..." | Read more » | over 11 years ago | |||
| Tom_H | "I was able to get a copy of the article. From a brief scan it looks very pertinent to what we are doing/discussing, but I have not really read it y..." | Read more » | almost 12 years ago | |||
| cfastie | "Well done,Tom. This article which was mentioned at the Google group, discusses the issue of focusing on the spectral image. It even has an equatio..." | Read more » | almost 12 years ago |