Digitisation

Once you have taken the photograph, transferred it to your computer, given it a catalogue number and made a note of the digital metadata in your catalogue, the next step is to store and backup the digital files.

Backing up means storing another digital copy of your photograph in a different place or on another device.

Keep the original on a portable hard drive marked with 'preservation copies' so you can keep them separate from access copies. Change these hard drives every couple of years to reduce the risk of them failing.

You must save your digital files in more than one location. It's easy to accidentally delete files, or files may become corrupted so they can't be opened. Saving them in multiple places means there is always a spare copy. For example, you could save one copy of a file in your computer filing system, one in a cloud storage system and one on a USB stick or a portable hard drive.

Think of the acronym 'LOCKSS' - 'Lots of Copies Keeps Stuff Safe'!

Cloud storage

'The cloud' is online storage space which you access over the internet and is provided by a company or place outside of where it is being used (like the way electricity is stored and made available to its users). You can make use of this storage space without having to worry about how it works behind the scenes.

The advantage of cloud storage is that you can access and download your archived digital records from any computer connected to the internet. It is much less likely that digital records will be lost permanently, as there will always be a chance of obtaining a copy.

Your group can also work together on creating your key documents simultaneously from different locations. You can protect your cloud storage with passwords so that the records are kept securely.

Cloud storage requires that you have the internet, so it's a good idea not to have it as your only place to store files - you will need to have copies offline, in hard drives or on your computer.

You generally need to purchase a subscription to use a significant amount of cloud storage space, so think how you would fund this going forward. You will need to read the small print over who 'owns' the digital records on the cloud. There is also a small risk that if the cloud storage provider goes out of business, your records will be lost, so choose a well-known provider (rather than just the cheapest) to lessen the risk.

Filing images

Your filing system should reflect your cataloguing system and be consistent across every place you use to store your images.

Deleting from the memory card

Once you've transferred the files, delete the originals from the camera's memory card.

This will free up space and avoid confusion about different versions and you should make this part of your digitisation process.

Preservation and access copies

As well as keeping backup copies, you may want to keep copies for preservation and access in different formats.

A preservation copy of a file should be the best possible quality version of the image. You can use the preservation copy as the template for creating access copies. A good file format to use for the preservation copy of an image is a TIFF. This file will be quite large and may take up a lot of storage space.

An access copy of a file is a version for sharing whether for use by researchers, commercial purposes such as in a book or article, or for publishing on your website. They are lower-quality files that take up much less space and can be sent in emails. JPEG is a good file format to use for access copies.

Shelf life

Technology is changing all the time, so anything stored digitally has a limited shelf life. Think about VHS, cassette tapes and floppy disks - all once commonly used and now all obsolete. Keep track of the latest file formats and storage methods. Professional archivists can give you advice about developments in technology, or you can check on the Norfolk Archives Network forum.