Photographing historic buildings - notes for surveyors

Guidelines for surveyors who are photographing historic buildings for the purpose of a survey in Northern Ireland. This supersedes former Technical Note No. 36, and gives broad guidance for taking photographs of listed and historic buildings and structures.

Tips

The basic technical requirement of any photograph taken for the purpose of survey is that it is correctly exposed and sharp of focus.

Images should be recorded at the highest possible resolution that your camera allows with the finest quality setting.

the structures should not be photographed in isolation
close-up detail should be photographed if of interest
every attempt should be made to furnish views of interiors
permission to photograph should be sought if it is necessary to enter a building or its grounds
it’s recommended that date indicators are set correctly for digital images as you may be required to confirm that the camera date is accurate for each record - this date will appear in the ‘Exif’ data automatically attached to each image - these are often erroneous and can cause much confusion at a later stage

Equipment

Cameras

Studio Adams Yard, Castle Upton, Templepatrick in County Antrim, Northern Ireland

Details should be recorded in as much detail as possible such as the ironmongery shown here. Longer exposure achieves this as it records fine detail which cannot be seen from a distance.

The best solution is to use a digital SLR camera with interchangeable lenses. One advantage of using a digital camera is that the images can be reviewed before leaving the building making sure that all images need have been correctly captured. A minimum of 18 MP is required in order to capture high quality images with adequate details.

Tripod

A substantial tripod is necessary, particularly when photographing large interiors. For example, compare the general photos of a church interior, one taken with a tripod and the other with an inadequate flash. Not only is the tripod photograph more pleasing to look at, but it has recorded much more detail in the roof structure.

A general rule of thumb is not to try to hand hold at a shutter speed lower than the focal length of the lens. So,

if using a lens at a wide-angle setting - 28mm, you should use a 30th of a second or faster
if using a 100mm lens then 125th of a second should keep camera shake at bay

Our Lady of Bethlehem Abbey, Portglenone

Camera shake can occur at any speed and you should always adopt a stable stance with feet shoulder width apart with the camera held in both hands. The shutter speed will normally be displayed on the camera. Some cameras will warn when camera shake is likely. If a tripod is not accessible, slower shutter speeds can be tried by bracing yourself and the camera against a support such as a column, door jamb or a church pew. Using a remote with a tripod is also advised for long exposures to avoid any shake created by manually depressing the shutter release button.

Flash

Most of the recommended cameras have an integral flash unit. This will be adequate for recording details up to 3m away. They are not adequate for photographing large interiors - see above and the need for a tripod. A hot shoe mounted flash unit or a slave flash unit will allow for the flash to be redirected to create diffused light and minimise harsh shadows which can obscure details.

Quality

Check your photographs on the camera before you leave the building. If in doubt take several photos of the same subject at different exposures (bracketing).

Technical and general considerations

General

The extent of the photographic record should be tailored to the building. Note: if a building has little or no historic interior then take sufficient photographs to record this fact. Your survey needs to be comprehensive, including images of alterations, extensions etc. and any development in the immediate setting. These will be valuable when considering the positive and negative features of the building and hence its listability.

Extent of Listing

All buildings/ structures that are to be included in the Extent of Listing should be fully photographed.

Guidelines about people and car number plates:

generally avoid including people – ask them to step aside
never photograph children, or young people under 18
avoid photographing car number plates wherever possible

Exposure

Photographs are only of value if correctly exposed so that the detail can be seen and the subject evaluated. For record purposes the best type of weather is a bright day where a high canopy of light cloud forms a uniform non-directional light. Unfortunately we are not always able to choose the survey weather and difficult conditions need to be understood and compensated for. When there is direct sunlight there will always be at least one elevation where the sun will be shining directly at the camera lens, and the elevation you are trying to record will be in shadow.

If sunlight shines directly into the lens it will cause ‘flare’. To prevent this, shade the lens with your hand or a lens hood. In these instances, if you use the auto exposure setting, it is likely to result in the shaded elevation being substantially underexposed and little or no detail will be recorded. There are two ways to overcome this:

walk close to the shaded elevation and take a manual exposure reading or lock the exposure value taken
take a ‘spot reading’ from the shaded elevation

Check the camera’s manual to see how your camera can be used in this way.

Deliberately overriding the cameras automatic exposure setting can be useful in other situations. On ‘Auto’ mode the camera takes several exposure readings from parts of the whole scene and then uses an average exposure. This will be suitable for most scenes with average highlights and shadows. As we have seen earlier this can lead to underexposure when shooting towards the sun.

Another instance that will lead to an underexposed photograph, is where you are photographing a very light coloured building illuminated by strong sunlight falling directly onto it. The auto exposure system will tend to produce an exposure that will record the building as light grey and you will have to override the auto setting by either taking a reading from an ‘average’ part of the scene or deliberately overexposing by up to a whole stop. If in doubt bracket some exposures.

Photographing stained glass windows

In most instances the camera is used to record light that has been reflected off the subject back to the camera. This is not the situation for a stained glass window where the camera is used to record the light passing through the glass.

An exposure reading must be taken of the light passing through the window and the photo deliberately underexposed by about 1.5 stops to capture the true colour of the glass. This means that if the camera gives a spot reading of 30th sec at f4 then the best exposure would be 30th sec at between f5.6 and f8. This can be adjusted manually or most cameras have a method for deliberately under or over exposing.

Direct Flash should never be used to photograph stained glass windows.

Labelling

Each photograph should be annotated with the external elevation (S) or internal room (G3) as recorded on the thumb-nail sketches of each floor. Poorly labelled photographs are worthless.

Photographing a building for the Second Survey

The purpose of the photographic survey is to provide a comprehensive, high quality visual record of the building and its setting at a moment in time. These images underpin HED’s day to day work in spatial planning and enforcement, and are the most significant ongoing contribution to the national heritage archive.

Records that may seem quite ordinary now can gain greater significance for future generations. HED has many photographs taken 30 – 40 years ago that are the only record of a particular building or building type.

For structures such as bridges, telephone kiosks, memorials and milestones, photographs should show the structure in its immediate and wider setting and one of each significant elevation. Also required are close up images of all significant details e.g. date stones, inscriptions, structure or materials

Photographs for publication

For publication purposes you should take a picture of the building that shows it at its best.

The building in its setting

The photographic record should include a minimum of three images of the building in its setting. The setting of a listed building can be defined as the immediate and extended environment that is part of, or contributes to, its significance and distinctive character.

It is up to the Contractor to identify those images which best describe the setting of a building or structure. These should always include the building in its immediate environment – for example:

the building and its immediate neighbours and longer views up and down the street
additional photographs may be long views towards the building (for example a vernacular building in the wider landscape) or an urban skyline
views from the building, particularly where they are part of an intentional design – for example within a designed landscape – must also be considered
the spaces and relationships between groups of buildings, particularly where there is, or was, a functional relationship (mill, factory, farmyard), are also important

See HED’s publication ‘Guidance on Setting and the Historic Environment’ for further information.

If the setting of a building or structure is extensive then the number of images and points of view should reflect this. Setting is not confined to views where the building is visible in juxtaposition with other buildings or landscape – there may be occasions where, for example, the approach to a building (where the building itself is not seen) contributes to its significance

General exterior photographs

Gosford Castle

These will be of the main elevations taken at an angle to the elevations to illustrate the three dimensions of the building and will normally illustrate the best views.

Elevation photographs

These will be taken at right angles to the elevations. You should capture the whole elevation in a single photograph if this viewpoint is possible. If not then several photographs should be taken to record the whole facade. In a large building, it may be necessary to use both approaches to record sufficient detail.

In a street situation, an oblique view may be the only way that the full height and width of a building can be captured as a single picture.

External details

Crumlin Road Gaol

Windows, doors and any other details such as stone carvings, date stones or decorative RW hoppers should be recorded separately.

Internal rooms

General photographs should record the principal rooms on all floors. Also photograph historic details - doors, architraves, skirtings, fireplaces, window and door encasements etc. if these are not clear in the general photographs, or are of particular note.

Use natural light and a tripod where possible but the small flash on most cameras will usually be adequate for small rooms and recording details. When using flash take the photograph at an angle to prevent the flash bouncing off the feature and appearing in the photograph.

Sometimes an owner will not be keen to allow internal photos to be taken. Any photos are for Historical Environment Division use only and will not be used in publications or released to the public without the owner’s consent.

Make every effort to record and photograph the roof structure

Often owners will have photographs, paintings or other documents that are of great interest in relation to the building. You should record these. Where the photograph or painting is in a glass frame, use natural lighting (if possible) and photograph it at a slight angle to avoid reflections.

External features

Gates, gate screens, garden features such as balustrading and outbuildings should be recorded.

Outbuilding and other separate buildings should be fully recorded if they are likely to be included in the listing.

Other images to be captured and entered:

Thumbnail building plans and complex site plans - these can be digitised on a flat-bed scanner or by photographing at the same resolution as the digital photographs