Guides
Part of Home archive shelving: line the wood or replace the unit
4 points on home archive lighting that matter
Lighting a collection: lamp choice is a preservation decision as well as a photographic one. Why some LED lamps fade material faster than the lamps they replaced.
What to take away
- Lamp quality varies enormously, and some LED lamps fade material faster than the lamps they replaced.
- Good LED lamps exist and cause less damage than the best previous lamps, and far less than daylight.
- Distance and angle matter as much as the lamp. Get the fitting away from the object.
- For photographing a collection, two lights at a low angle beat one overhead every time.
The LED problem nobody warns buyers about
Replacing an old lamp with an LED is often assumed to be an improvement. The Canadian Conservation Institute's technical bulletin on LED lighting for museums is more careful.
Lamp damage comparison
UV-filtered quartz halogen
- Fading rate
- baseline
- Light quality
- adequate
- Availability
- older lamps
Poor LED
- Fading rate
- up to double
- Light quality
- often inadequate
- Availability
- common
Good LED
- Fading rate
- less than baseline
- Light quality
- high
- Availability
- increasing
Daylight
- Fading rate
- worst
- Light quality
- high
- Availability
- always
LED lamps are replacing incandescent and fluorescent lamps used for decades, but the transition is not simple. LED lamps vary widely in light quality, and concerns have been raised about elevated rates of damage.
Its finding is worth quoting in substance. Most LED lamps on the market do not produce light of adequate quality and do not match quartz halogen or museum grade fluorescent lamps. Some LED lamps can cause up to double the rate of fading of an ultraviolet-filtered quartz halogen lamp.
The second half matters as much. LED lamps producing high quality light are available and increasing in number. Those lamps cause less damage than the best lamps of the past, and much less than daylight.
The bulletin defines what makes a lamp good or excellent and works through a step-by-step selection process. The household version is simpler: lamp quality is a real variable, cheap is often worse rather than merely dimmer, and daylight remains the worst option in the room.
Getting the fitting away from the object
Position matters independently of lamp choice. The Canadian Conservation Institute's note on track lighting calls it perhaps the most flexible system for museums and galleries, while noting that fluorescent tubes still have their place and each system has advantages and disadvantages.
Track lighting setups
Single track
- Track spacing
- optimum distance from wall
- Best for
- moderate objects
- Risk
- top of large object close to lamp
Double track
- Track spacing
- 60–90 cm apart
- Best for
- large objects
- Risk
- reduced
Single track with perpendiculars
- Track spacing
- short perpendicular sections
- Best for
- flexibility
- Risk
- reduced
Two of its practical points transfer to a room at home. There is an optimum distance for the track from the wall, and it should be observed carefully because it gives good illumination for objects of moderate size.
But when large objects are hung, following the formula puts the top of the object very close to the lamp. Where more flexibility is wanted, a double track system with tracks 60 to 90 cm apart offers it, or a single track with short perpendicular sections.
Read that as a warning about the tall item on the wall. The top of a large framed piece often sits far closer to the light than the middle does, and it fades first.
Turning the fitting off is free
The cheapest lighting improvement in any house is a switch. Display lighting that runs whenever the room light is on delivers far more exposure than the hours anybody actually spends looking at the wall.
Halve hours, halve damage
50% less exposure
Display lighting on its own switch or timer
Turn on for visitors, not left running
Costs nothing, works with any lamp
Put display lighting on its own switch, or on a timer, and treat it as something turned on for visitors rather than left running. Halving the hours halves the damage, and it costs nothing, needs no purchase, and works regardless of how good the lamp is.
Photographing rather than displaying
For photographing a collection the requirements invert. You want more light for a short time rather than less light continuously.
- Two lights, one either side at roughly forty-five degrees, kills reflections.
- Add one raking light at a low angle for a second frame showing surface texture.
- Keep the lamps far enough back that you cannot feel heat on the object.
- Switch them off between shots. Setup time is when most exposure happens.
- Include a gray card or ruler in one frame so color and scale are recorded.
That routine gives better results than any single expensive lamp, and it exposes the object for minutes rather than hours.
Our guide to supplies compared on price and upkeep covers where lighting sits in the budget, and the notes on displaying keepsakes cover the light budget for anything left on a wall.
