Light a painting from an angle of roughly 30 degrees from vertical, keep the level modest, and keep ultraviolet out. The angle controls glare, and the level and ultraviolet control damage. The Canadian Conservation Institute states that the average person perceives most colours reasonably well at 50 lux, that details in darker colours may require 150 lux, and that where ultraviolet cannot be blocked completely, levels should not exceed 75 microwatts per lumen.
Those figures are lower than most people expect, and the reason is that light damage accumulates and never reverses. A painting is not safe because each individual day looks harmless. The days add up, and faded pigment does not come back.
Key takeaways
- Aim a light at about 30 degrees from vertical to avoid both glare and a shadow from the frame.
- 150 lux is the CCI figure that applies to detail in the darker colours of oil and acrylic paintings.
- Keep ultraviolet below 75 microwatts per lumen where it cannot be excluded entirely.
- Never hang a painting where direct sunlight falls on it.
- Light damage is cumulative and permanent, so lower and shorter is always safer.
The angle, and why 30 degrees
A light placed directly above a painting, shining almost straight down, casts a shadow from the top of the frame across the upper part of the picture and leaves the lower part dim. A light placed too far out, closer to horizontal, reflects off the varnish or the glazing straight into the viewer's eye.
Around 30 degrees from vertical avoids both. The beam clears the frame, reaches the whole surface reasonably evenly, and reflects downward away from a standing viewer rather than into their face. It is a starting point rather than a precise requirement: a deep frame needs a slightly wider angle to clear it, and a tall painting may need the light further back.
Glazed works need more care than unglazed ones, because glass reflects far more than varnish. Where a painting is glazed and lighting is difficult, non reflective glazing solves the problem more reliably than repositioning the light.
The level, and what the numbers mean
Lux measures how much light lands on a surface. The CCI figures worth knowing are these: most colours read reasonably well at 50 lux, and details in darker colours may require 150 lux. For oil and acrylic paintings, which is what most collectors own, 150 lux is the practical working figure.
For a sense of scale, a brightly lit room sits far above that, and direct daylight is higher again by orders of magnitude. This is why a painting on a wall that catches afternoon sun is receiving vastly more light than any conservator would recommend, even though the room feels normal.
The damage is cumulative and it trades against time. Twice the light for half the time does the same harm. That relationship is what makes a bright wall dangerous over years rather than days, and it is also what makes a simple habit effective: turning display lighting off when the room is empty genuinely reduces total exposure.
Ultraviolet
Ultraviolet radiation is more damaging per unit than visible light and contributes nothing to seeing the picture, so the sensible target is to remove as much as possible. The CCI advises that where it cannot be blocked completely, levels should not exceed 75 microwatts per lumen.
Daylight is the main source in a home. Ultraviolet filtering film on windows, or ultraviolet filtering glazing on the frame, addresses it directly. Modern LED lighting emits very little ultraviolet, which is one of its practical advantages for display, along with low heat output.
Choosing a light
LED is the straightforward choice for lighting art at home. It runs cool, which matters because heat dries the air immediately around the painting, and it emits negligible ultraviolet. Older halogen fittings produce significant heat and should be kept well back if used at all.
Two qualities are worth checking on the packaging. Colour rendering describes how faithfully a light source shows colour, and a higher figure means the painting looks closer to how it appears in daylight. Colour temperature describes whether the light is warm or cool; a warmer light suits most domestic rooms and most paintings, while a cool light can make warm pigments look flat.
Dimmable fittings are worth the small extra cost. They let you set a level that suits the room rather than accepting whatever the fitting produces, and lowering the level is the simplest protective measure available.
Positioning options
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Ceiling mounted directional fittings. The most flexible option. Position them so the beam meets the painting at about 30 degrees, which usually means mounting them a comfortable distance out from the wall rather than directly above it.
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Track lighting. Suits several works on one wall, since individual heads can be aimed separately and moved when the arrangement changes.
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Picture lights fitted to the frame. Attractive and traditional, but they light from very close range and at a steep angle, which tends to produce a bright band at the top and a dim lower area. They also put a heat source close to the surface. Choose LED if using one.
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Ambient room lighting alone. Perfectly acceptable, and the lowest risk option of all. A painting does not require dedicated lighting to be enjoyed.
Daylight is the real risk
No artificial fitting in a home is likely to approach the exposure a painting gets from sitting opposite a south facing window. Direct sunlight should never fall on a painting.
When choosing a wall, watch where the sun actually falls across a full day and across seasons, since the low winter sun reaches much further into a room than the high summer sun. Sheer blinds, curtains or ultraviolet filtering film reduce the problem where a wall is otherwise ideal.
Rotating works between a bright wall and a quiet one spreads exposure rather than concentrating it on one piece, which is a practical approach for collectors with more work than wall space. The wider environmental picture, including humidity and temperature, is covered in our guide to protecting art from light and humidity.
Frequently asked questions
How bright should the light on a painting be?
Keep it modest. The Canadian Conservation Institute states that the average person perceives most colours reasonably well at 50 lux, and that details in darker colours may require 150 lux, which is the practical working figure for oil and acrylic paintings. Light damage accumulates and cannot be reversed, so a lower level maintained over years protects the work far better than a bright display.
At what angle should a picture light be aimed?
Aim for roughly 30 degrees from vertical. A light shining almost straight down casts a shadow from the top of the frame across the picture and leaves the bottom dim, while a light closer to horizontal reflects off the varnish or glazing into the viewer's eye. Thirty degrees clears the frame and reflects downward, away from a standing viewer. A deep frame needs a slightly wider angle.
Does sunlight damage paintings?
Yes, and it is the largest lighting risk in a home by a wide margin. Direct sunlight delivers vastly more light than any recommended display level, and the damage accumulates permanently. Watch where the sun actually falls across a full day and across seasons, since low winter sun reaches much further into a room than high summer sun, then choose a wall it does not reach.
What is the ultraviolet limit for displaying art?
The Canadian Conservation Institute advises that where ultraviolet radiation cannot be blocked completely, levels should not exceed 75 microwatts per lumen. Ultraviolet is more damaging per unit than visible light and contributes nothing to seeing the picture, so removing as much as possible is sensible. Daylight is the main household source, addressed with filtering film on windows or filtering glazing on the frame.
Are LED lights safe for original paintings?
LED is the best common choice for lighting art at home. It emits negligible ultraviolet and runs cool, which matters because heat dries the air immediately around a painting. Older halogen fittings produce significant heat and should be kept well back if used at all. Look for a high colour rendering figure on the packaging so the painting's colours read faithfully.
Are picture lights mounted on the frame a good idea?
They look traditional but they light from close range at a steep angle, which typically produces a bright band across the top of the picture and a dim lower area. They also place a heat source near the paint surface. If you want one, choose an LED version to minimise both heat and ultraviolet, and accept that the illumination will be less even than a fitting mounted further back.
Does a painting need dedicated lighting?
No. Ambient room lighting alone is perfectly acceptable and is the lowest risk option available, since it adds no concentrated exposure to the surface. Dedicated lighting is a presentation choice rather than a requirement. Where a room already has reasonable general light, adding a fitting aimed at the painting increases its total lifetime exposure for an aesthetic benefit only.
Does turning lights off actually help?
Yes, because light damage trades directly against time: twice the light for half the duration causes the same harm. Turning display lighting off when a room is unoccupied genuinely reduces total lifetime exposure, and it is the simplest protective habit available. The same logic supports dimmable fittings, since a lower level maintained over years is meaningfully safer than a brighter one.
How do I light a painting behind glass?
Glazed works reflect far more than unglazed ones, so the angle matters more. Keep to about 30 degrees from vertical and check the result from where people actually stand, since a reflection invisible from one position can dominate from another. Where the geometry of the room makes this impossible, non reflective glazing solves the problem more reliably than moving the light.
Can I rotate paintings to reduce light exposure?
Yes, and it is a sound approach for anyone with more work than wall space. Moving pieces between a bright wall and a quieter one spreads exposure across the collection instead of concentrating it on whichever work happens to occupy the brightest position. Since damage accumulates with total exposure, halving the time a piece spends on a bright wall halves that contribution.
References
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Environmental Guidelines for Paintings, CCI Notes 10/4. Canadian Conservation Institute, Government of Canada. Published 1990, revised 2016. Accessed 5 September 2026. Source for the 50 and 150 lux figures and the 75 microwatts per lumen ultraviolet limit.
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Agent of deterioration: light, ultraviolet and infrared. Canadian Conservation Institute, Government of Canada. Accessed 5 September 2026. Source for the principle that light damage is cumulative and irreversible, and that exposure trades against time.
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On the 30 degree angle: a display convention in common professional use rather than a published standard, and described as a starting point in the text. Checked 5 September 2026.
