Let there be light
Our relationship with light at Ham House is a complex one. We have some of the earliest sash windows that were designed to let in as much light as possible. However, 400 years ago those shutters were closed and the house fell into darkness for months, even years. So how then do we showcase our beautiful treasures in their original settings, whilst also safeguarding them for the future against the threat of irreversible damage and deterioration? The answer: hard work, vigilance and science.
When we talk about light damage to an historic object, we largely mean two things are happening: the fading of pigments and dyes, and the structural weakening of material. It’s hard to believe that something seemingly so gentle like light can leave an object mis-coloured and crumbling. The prevention of this damage is one of the biggest challenges for the conservation team at Ham House.
We battle against ultraviolet light, which is the most destructive element of light, by fitting a film to every single window pane in the rooms open to our visitors, and there are approximately 740 individual panes to cut and fit for. We then use special light monitors to measure the light exposure in a room and adjust the blinds accordingly throughout the day to allow in as much daylight as possible while still creating a safe environment for our very old and fragile collection.
Light damage is cumulative, so we calculate our annual light exposure dose and organise our opening times around the maximum dose of light we can allow for that year. We are looking into ways to provide more artificial light to our rooms so we can open for longer without needing daylight, much as museums and galleries in purpose built spaces can do. This year we are working with national specialists in Preventative Conservation to undertake two experiments. The first uses camera technology to monitor sunlight exposure in one room over a year to better understand how light affects our interiors at different times and seasons. If you step into the Voluary you may spot the camera mounted above the doorway, but don’t worry about being snapped, the camera is taking very long exposure pictures at regular intervals and visitors will simply appear as ghostly shapes moving through the room while light readings are captured.
The other experiment measures light diffusion through different types of blinds. Two different types have been installed in the Duke’s Dressing Room and the Withdrawing Room. Monthly light readings and careful monitoring of the objects within these rooms will tell us which of the two blinds is best at protecting the delicate interiors at Ham House. As a baseline to these experiments, a retractable light monitor has also been attached to the roof of Ham House.
We are constantly striving to improve our management of light at Ham House to provide the most visually stunning experience for our visitors today, while preserving our treasures for other generations to enjoy long into the future. Please come visit us to find out more about how we look after Ham House forever, for everyone.