340 nm LED (first impressions)

[Stefano]

a couple of comments.....

 

The human eye lens fluoresces in the blue range under UV stimulation around 320-380. (Reference needed. Cannot find it at the moment.)

The retina can detect this fluorescence. I do not recall reading how this might affect one's perception of UV light from UV-LEDs, but it must affect it in some way, yes?

The lens fluoresces in a diffuse, “milky” way. It is like the diffuse blue fluorescence of most clear plastics. The (few) times I used 365 nm LEDs in the dark without goggles I was seeing cloudy, like if I had dust on my eyes, because of the lens fluorescence. It was quite annoying. Everything went away by putting my polycarbonate goggles on. What I saw instead was a clear, sharp image of the square chip, blue in color, and I had to focus like if it was far away (we are shortsighted in UV, violet and even blue light).

[dabateman]

So, if my camera really sees 340 nm (it seems unlikely), should it see it as green under WB? Is 340 nm green for every sensor, like 360 nm is yellow and 390 nm blue-violet?

 

Maybe maybe not. Just saw this QE graph. Don't know who supplies the dyes though. I was surprised that most sensors actually use Fuji dyes for green red and blue.

 

[Stefano]

In this sensor the red and green channels are very similar in UV, so I would expect yellow at 340 nm. I got yellow, but it was with a white-balance applied.

 

You do indeed get yellow with your EM1.