Museum lighting Pure and simple

[Jim Stettler]

I used to research conservation techniques. I found this lighting article years ago. I just found a hard copy of it, so I thought I would post the link.

http://www.nouvir.com/pdfs/MuseumLighting.pdf

Jim S.

[Babybearjs]

Interesting Article. something I've been aware of for years!

[Butch Harlow]

Not only interesting, but surprisingly affordable.

[TelePlay]

     Regular Member Post

The companion topic to this is photography: spectral light reflected, the sensitivity of camera crystals and the software implanted in digital cameras by the manufacturer to compensate for light source and crystal characteristics.

I've posted a few times that color is the absence of light frequencies reflected (absorbing some visible frequencies to create a reflected color - black is total absorption of visible light and white is total reflection of visible light) by an object and this museum piece speaks to removing those IR and UV frequencies, that can't be seen or photographed anyway, that would be absorbed by the object and in doing so damaging the object, including changing the reflective properties of the object.

It's a nice article and could be helpful with setting up a light station to photograph items to be listed on eBay, or posted here,to show their true colors. It's a complex issue, photography, in that no two cameras models are the same so how they react to even museum quality light depends on the background, phone color and camera software - I've had my share of frustrating hours taking images that just didn't look right thanks the the camera's software manipulation of the captured color image based on the camera's light sensor.

The last factor with respect to phones is the plastic itself, the chemical composition or mixture used by the manufacturer to create a color, to absorb parts of white light and reflect others to create a color. Some plastics can be more easily damaged by even visible light over time but more slowly in that visible light is not as damaging as IR (heat/microwave) and UV (high energy/x-ray) energies that can't be seen anyway, or photographed. This gets into the field of quantum physics of colored plastics, something I do believe only a physicist could explain.

I don't think there is anything that does not change color over time if exposed to a light source from carpeting to cars to paint on a wall (remove a picture that's been hanging for 10-20 years and you might see the frame image on the wall.

Thanks for posting the article, good information for greatly reducing damage due to light. Something to think about.

[Dan/Panther]

How does L.E.D. lighting stack up to regular lighting. I know pure white LED light shows color very well. I don't know about Photon damage.

D/P

[Jim Stettler]

How does L.E.D. lighting stack up to regular lighting. I know pure white LED light shows color very well. I don't know about Photon damage.

D/P

LED's don't have the UV problems of other lightning.
They do make UV covers for fluorescent tubes.

I am leaning toward flat panel LED's. They edge light a piece of white plastic. I can find 2x4 panels for around $100 locally. 2x2 panels aren't much cheaper.
Jim

[TelePlay]

     Regular Member Post

How does L.E.D. lighting stack up to regular lighting. I know pure white LED light shows color very well. I don't know about Photon damage.

In way too many words here, the complete electromagnetic spectrum is quite wide ranging from very long to very short wavelengths to very high energy, short wavelengths (first image below) with the visible portion being quite small in range.

The last image is a comparison of artificial light source output by wavelength. Incandescent most closely approximates the sun. CLF bulbs have the poorest visible light spectrum. LEDs are pretty good but have some drop out areas in their spectrum. When it comes to seeing color, if part of the spectrum is missing, the color won't be seen the same as it would in sun light.

Regardless of the source, they all produce electromagnetic energy in the visible range which can affect that which is being illuminated by the light source. It comes down to how the item being illuminated is affected by the light being used to illuminate it. LED photons at a certain wavelength are the same as photons at that wavelength created by a CFL, incandescent bulb or the sun.

LEDs do produce most of their light in the visible spectrum meaning they produce little to no ultraviolet or infrared, one of the features I like with LEDs in that they don't get as hot to the touch as incandescent bulbs reducing greatly the risk of melting damage or fire to nearby objects. The light, photons, they do produce in the visible spectrum can still affect what they are illuminating but it would seem the risk of damage is greatly reduced with LED bulbs.

LEDs come in soft or warm white (about 2700K equivalent) to cool daylight (5000 K equivalent) and I found that a mixture of 75% daylight and 25% soft white when taking photos with a digital camera works best, with a slightly off white to 15% grey background. For lighting in my house, I am still torn between the too yellow soft white and too bright daylight bulbs - they make bulbs in the middle, about 3000K or 3200K, but I can't find them on store shelves and special orders are expensive.


(BTW:  Home Depot will take any or all of your CFLs at their service desk in a no charge recycling service they offer to keep mercury out of the landfills - I recently replaced about 25 CFLs with LEDs and Home Depot took all 25 bulb without question)

[Jim Stettler]

I have found flat panels from China with multiple K  outputs. I assume the have a hard switch or leads  to set the K level
I have considered  color changing panels. These are controlled via a remote control.
The longer I wait, The varieties increase and the price decreases.
JMO,
Jim S.

[TelePlay]

     Regular Member Post

I have found flat panels from China with multiple K  outputs. I assume the have a hard switch or leads  to set the K level
I have considered  color changing panels. These are controlled via a remote control.
The longer I wait, The varieties increase and the price decreases.

It would be really interesting to obtain a spectral scan, by wavelength, of these panels at different temperature setting, 2700K, 3200K and 5000K.

I would think the spectrum would be the same but the intensity at different wavelengths would change. If you get a controllable panel, do you have something that will record the spectrum.

I found this scan, the left is "white" light and the right is broken down into red, blue and green components.

A photon is a photon regardless of source with the only variables being wavelength and intensity - hard to duplicate the full spectrum white light given off by the nuclear activity in the sun.