mel80
New member
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Further investigation on this subject has also revealed that, to all intents and purposes, as soon as a person’s eyes are subjected to white light, their dark adaptation time starts again from zero.
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That's quite clearly rubbish though isn't it? After all, a good proportion of stars emit white light, and so do most light houses. I don't recall having to start my night vision from 'zero' just because I've spotted a white nav light. It is intensity that has the biggest effect on night vision, not colour.
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he had removed the red screen and allowed the unfiltered white light to illuminate the chart table.
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Unsurprisingly, a light with all wavelengths filtered out apart from one will be a lot dimmer than the same light unfiltered. The colour of the filter is, to a large extent irrelevent compared to the act of removing the filter.
There are some advantages to using red light for preserving vision, but there are also many advantages to using white. However, if you do use white, it is very important to be able to adjust the intensity.
Further investigation on this subject has also revealed that, to all intents and purposes, as soon as a person’s eyes are subjected to white light, their dark adaptation time starts again from zero.
[/ QUOTE ]
That's quite clearly rubbish though isn't it? After all, a good proportion of stars emit white light, and so do most light houses. I don't recall having to start my night vision from 'zero' just because I've spotted a white nav light. It is intensity that has the biggest effect on night vision, not colour.
[ QUOTE ]
he had removed the red screen and allowed the unfiltered white light to illuminate the chart table.
[/ QUOTE ]
Unsurprisingly, a light with all wavelengths filtered out apart from one will be a lot dimmer than the same light unfiltered. The colour of the filter is, to a large extent irrelevent compared to the act of removing the filter.
There are some advantages to using red light for preserving vision, but there are also many advantages to using white. However, if you do use white, it is very important to be able to adjust the intensity.
