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Museum Lighting

(Musings on the LOW LIGHT conditions in some museums)

Museums. Fascinating places full of extraordinary priceless ancient exhibits, and visitors squinting in the dark trying to see what the exhibits are! Yes, well it's a style, perhaps to give the visitors an experience of mystery to simulate the feeling of discovery like the great explorers uncovering historic tombs and lost catacombs. No? Well apparently not - it's because the lighting has to be kept VERY DIM to stop the light from fading and ageing the exhibits. I've even seen museums banning FLASH photography because of the notion that it will fade the relics on show!

You can understand museums banning people using a FLASH because it's a nuisance, like people nattering on their mobile phones, or munching on fish and chips. But the lighting is more of an artefact-preservation matter. Bright light destroys some types of antiquities.

Now let's get this in proportion. If a museum had installed great arclamps and stage-lighting, then within a few years some of the ancient artefacts would crumble to dust. But no-one's suggesting that. The idea is instead to have lighting which is as bright as possible without causing any damage to the exhibits. Of course ideally it would be nice if you could have light that lets you see stuff without including any of the light that causes fading and ageing. Oddly, this IS possible!

Light for the purpose of SEEING can be anywhere in the "visual spectrum", but light that fades fabric, causes sun-tan, and generally alters that which it touches, is light at the HIGH END of the spectrum. So why do museums install those little shop-window lights that produce loads of Ultraviolet?

Here's what I propose as a practical museum lighting scheme which is bright and yet doesn't damage the artefacts: Midrange brightness lights which are towards the LOW END of the frequency spectrum. It's to do with COLOUR TEMPERATURE. Standard 100-watt lightbulbs and old-style car headlamps are much lower temperature and so produce less UV Ultraviolet. It's possible to get an even lower colour temperature by running the lighting at a slightly lower voltage!

I don't expect museum curators to take my word for this. But such experts in the field of history are scientists and understand that a scientific theory can be put to the test by EXPERIMENTATION. It would be quite practical to put some fragments of ancient material under different lighting conditions and see if this theory is right! (It's possible to accelerate the testing by changing the luminosity on a calibrated scale).

Those who are totally sceptical about this may consider this notion: Supposing you illuminated a piece of cloth thousands of years old using a sunlamp and a similar piece using an ordinary lamp of the same brightness, don't you think the UV-blasted sample would disintegrate much sooner?!

Also, on the FLASH photography, whilst it's true that a photo flash is very bright and contains UV, it's very short duration. It would be interesting to put a sample of material on test and light it with a photo flash going off every second like a stroboscope and see how many million flashes are required to cause detectable damage.

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I'd be interested to hear from museum people about any of this. You can e-mail mee-mail here

I have been asked to recommend the book "Thomson, G. The Museum Environment" as a starting point for those who want to know more. Here are some useful references: The Museum Environment by Garry Thomson (Amazon UK) and The Museum Environment by Garry Thomson (Amazon.com)