Digitisation

Once you have prepared the item you are ready to capture an image of it and save it as a digital file. If you have more than one copy of an item choose the best version for digitisation.

Photographing the item

Make a list of the camera settings and add them to your digitisation plan, so the same settings are used now and in future projects. There are a several settings to think about:

• Ppi (pixels per inch): this is a measurement of the resolution of a computer display. Dots on a computer screen are also known as 'pixels'. The higher the ppi, the sharper and more detailed the image.
• Colour balance: how colours appear on screen
• Bit depth (or colour depth): how broad the range of colours is - this is measured in 'bits'

Some recommended settings

• Resolution - 300 ppi for text documents and maps, 600 ppi for photographs and illustrations
• Colour balance - Adobe RGB for colour images, grayscale gamma 2.2 for grayscale/black and white images
• Bit depth - 24-bit for colour images, 8-bit for grayscale/black and white images

It's a good idea to take the photographs in the same order as the documents are kept. This is because when you transfer them to your computer they'll be numbered in sequence.

Saving the images

Digital cameras contain a removable memory card which can to store hundreds of digital photos. The cameras are either wi-fi enabled or come with a USB lead to transfer photos from the camera to a computer. Install the camera's software on your computer and transfer the photographs from the camera's memory card as soon as you can. Always check you have transferred over all the images, in the order they were taken.

Numbering the files

Camera software usually lets you create a unique file name for each of your photos. Make sure the numbering system you use ties in with the archive's reference number for the physical document. An easy method is to add a sequence of numbers at the end of each image's reference number.

For example, you digitise a notebook in the Helen Smith Archive, reference number HS/1/3. It contains 12 pages, so when you photograph it you label each photo HS-1-3_001, HS-1-3_002 and so on, until the last page HS-1-3_012. (You can't include the 'slash' symbol in a file name.)

If you photograph large items using more than one image, you'll need to create a way of numbering the image for each part of the item. For example, _001 for top left, _002 for top right, _003 for bottom left, _004 for bottom right.

Metadata

Metadata is information that tells you about a digital item. (It literally means data about data.) For example, with a digital photograph, the metadata tells us the date and time the photograph was taken, the image size and resolution.

It is important to record this information in your catalogue.

If you are digitising only for access purposes, this is the only metadata you need to record. If you are digitising collections for preservation and management (for example, photographing a collection that is on loan to you), it is a good idea to also record the following information in the catalogue:

• The digital file number (eg HS-1-2_034)
• The date it was digitised (eg 12 February 2020)
• The name of the person who digitised it
• The file format (eg TIFF or JPEG)