Search results

I remember when holograms came in only one color, red. You could see them in science museums. The Edmund Scientific Catalog even had kits where you could make your own. In fact, they still do. Hologram Kit - 3d laser holograms | Edmund Scientific

As an avid wavelength collector on a budget, I've been looking for something like this. Unfortunately the price went up, but it's inspired me to look a little harder to see what else is out there in the way of cheap low-power 445s.

The current hex converter is based on information from Dan Bruton's website, which in turn is based on CIE 1931. The following diagram illustrates how it works. (Warning: this my own crude diagram.) The inner triangle represents the sRGB color space, which is what most people have on their...

Thanks for the link. I already had a look the site a year or two ago. The problem is, this can't be done with just RGB blending, in part because the human visual system is not exactly an RGB system. It has an RGB system inside of it, but it's way more complicated than that. Going by simple...

These threads are valuable resources. Many people come to them years later for valuable information. They are not just for entertainment and idle discussion. Just because some people have an issue, it doesn't make it my issue. After all, I run into these sorts of people all the time on Yahoo...

Correction: according to many authorities, pure red is not a spectral color. At 704nm the R/G ratio is still 15, meaning the red cones are stimulated 15 times as much as the green cones. If you're talking about cone fundamentals, that would still be orange-red. On the other hand, the whole...

Thanks. Glad to be of help.

:yabbmad: The original polls actually used the word "pure," a concept fundamental to color vision research as well as to the world of RGB. The word "true" was only used as a veiled insult to suggest that the whole concept is so subjective that it smacks or religion or ideology. :cryyy: Rather...

This question has already been researched to death. It's 704nm, although older studies have it as 700nm, which is close enough. At that wavelength the R/G ratio is 15. That means the red cones are 15 times as stimulated as the green cones. (At these wavelengths the blue cones play no significant...

Thanks for the encouragement, but I've decided to stop doing these polls. It's just not worth the aggravation. On the other hand, the Wikipedia article on azure (sky blue) says, "Its dominant wavelength is about 488 nm." That doesn't look right. Aren't 473nm lasers pretty close to sky blue? My...

I agree with your assessment of the color computer dots, although I'm not sure if you and I have the same thing. I have cheap generic sRGB. I am determined to have more than one color space in this HEX converter. Maybe we should start with two: sRGB and Adobe RGB. If we can figure out how to do...

Here are some ideas for the HEX convertor: By the way, I think the people who are so hostile to these threads have the same mentality as 911 conspiracy believers and people living in militia training camps in Idaho. Their very demeanor suggests a big burly guy sitting in a prison cell...

I think you're right. 532 is not the most perfect green at any level of intensity, and I was getting confused on the hue shift direction. Brighter green should be more yellow. Also, some of these studies are going in 10nm increments, so I'm still looking into this.

:wave:It looks like the HEX convertor may have been right about green after all: 510nm. I had seen that number before in various studies, but couldn’t wrap my brain around it. It conflicted with my own experience of 532nm lasers, and with what others here were seeing. However, I forgot to take...

I was familiar with the general idea, but it never really sank in until you told this story. Since color vision studies are often done at low light levels (e.g., monochrometer at 27 trolands) I've been trying to figure out how to attenuate my lasers by several orders of magnitude. Thanks to your...

Here's the link to the laser pointer. 980nm IR Infrared 5mW Laser Pointer Pen Currency Detector Anti Fake | eBay The cyan is clearly visible (along with the red) only by shining it directly into your eye. I think some people would be willing to take such a risk for a fraction of a second with...

Years ago I was driving along the freeway in LA around twilight time when I saw a skyscraper on fire. It was the First Interstate Bank building, tallest building in LA. (It had a big sign on top with the name of the building.) https://en.wikipedia.org/wiki/First_Interstate_Tower_fire Years...

Thanks. That's about what I was thinking on these wavelengths, although I'm not sure sure what "lemon yellow" means. Is there any detectible green in that?

Regarding previous posts, the English word "orange" certainly violates their own rule, as the examples given are gold and silver (on what to avoid in doubtful cases). However, none of the languages surveyed were English, so I don't think that's a valid criticism. Next, lots of researchers have...

I have never actually studied "color nomenclature theory" (as it is called) although I've run into it in passing. For example, just reading the kind of books they advertize in Scientific American, on linguistics, anthropology, evolutionary psychology, etc.. Even though I have studied many...