Are you interested in LED light?

[jitter]

Originally Posted by wwenze

Does that lamp happen to be marketed as 'dimmable' via standard AC light dimmers?

Most dimmers made for incandescents need a minimum load (e.g. 60-300 W). If you go below the minimum load, chances are the light may flicker. Dimmers made specifically for LEDs have no or a very low minimum load.

[5th element]

Originally Posted by AndrewT

That's not the way our eyes work.

It's the way that my eyes work, but that's because I am colour blind. There are swept tests, one of which you can find on youtube, of a dancing mosaic. A small square moves about the field of grey stones and sweeps from one end of the spectrum to the other, with normal vision you see the square slowly sweep through the visible spectrum.. With myself however the colourful square disappears twice, once at each interval where the receptors are supposed to overlap, but in me there's a small gap instead.

[tvrgeek]

Just like our hearing, it varies person to person. If anyone can find the test 5th mentions, it would be a fun test. Of course, you have to realize you are looking at it through a PC, whose display in also a set of overlapping bands based on the filters selected in the LCD. Trying to think how one could actually do a test like this. A hot-wire ( or sun) and a prism maybe?

[jackinnj]

I learned from making photographic prints (the wet chemistry way) that I had a different color balance in each eye.

[5th element]

Originally Posted by tvrgeek

Just like our hearing, it varies person to person. If anyone can find the test 5th mentions, it would be a fun test. Of course, you have to realize you are looking at it through a PC, whose display in also a set of overlapping bands based on the filters selected in the LCD. Trying to think how one could actually do a test like this. A hot-wire ( or sun) and a prism maybe?

The narrow band are relatively small, so I doubt a prism would really show this well. You might be able to see tiny colourless spots if you're colour blind, but I never have (not that I've ever been looking).

The computer might be an issue with the test, but from my experience it hasn't been. The first time I saw the test was when studying biology at A level. My biology teacher knew I was colour blind and not for my class but for another, she had told their teacher that I was, so when my class was in session and theirs was too along came the other teacher and requested my presence in their class because they were studying the eye and had this test set up. None of the other class had any student in it who was colour blind and they hadn't had the test explained to them before and indeed I hadn't been told what to expect either, but I guessed what was supposed to happen as soon as the test started. I was told to say what I see and when it got to the spot where the square vanished there were gasps of amazement when I said 'it's vanished'

This was on an old CRT monitor iirc and later on, on a DELL U2311H I performed the test again with my parents and they both saw the continuous colour changing square, where for me, it disappeared twice. I then performed the test again with my brother, he is also colour blind and I wanted to see if he saw things in the same way I did, or whether there were differences. There were however differences. We both saw the square vanish twice, but the size of the gaps between the different receptors was different for both of us, both in terms of size of gap and when the gaps started.

[jitter]

Originally Posted by tvrgeek

If anyone can find the test 5th mentions, it would be a fun test.

I think it's this one.

I'm know not colour blind, I passed an Ishihara test when I was seventeen when I was tested for military service (conscription). But in the video the colours do seem to vary in intensity, esp. when blue turns to purple they're only just present. Is this supposed to happen or is it the computer monitor?

[5th element]

Yes, that's the one. It doesn't work perfectly on the tablet as it tries to do some fancy dynamic compensation, but the square disappeared once between red/blue and almost vanished between yellow/red.

[tvrgeek]

Cool. I just watched it with an old Toshiba laptop and it looked pretty uniform through all the colors, maybe just a tad light in the tan. I was waiting for an intense yellow or mustard but I never say one.

What does that say? Nothing much as the latop is an unknown. It probably says I don't have a significant problem. As least something in these old bones still works. I would bet almost everyone in this forum would get slightly different results and we would not know if it was eyes or monitor.

When I was suggesting a prism, I was thinking of a slot to get very narrow bands and not be constrained by laser frequencies.

[wwenze]

Originally Posted by 5th element

Yes, that's the one. It doesn't work perfectly on the tablet as it tries to do some fancy dynamic compensation, but the square disappeared once between red/blue and almost vanished between yellow/red.

Yea... I was just wondering if that test would fail if the screen uses RGB OLEDs.

[Pano]

It's an interesting test, never seen it before. I'm going to try in on several different projectors and monitors to see if it makes a difference.
FWIW, LCD displays are notoriously bad on color. They tend to have reds that skew toward orange.