In my opinion, the purpose of restoration is not to “improve” the photographs according to today's standards. I'll try, with the knowledge that I have, to restore the image to its original state to show how it must have been looked after the development and printing by the photographer.
I distinguish three types of decay:
- Physical damage: tears, folds, scratches or cracks (in case of glass slides)
- Color casts: most of the time an overall yellow cast caused by exposure to light and/or local blue casts due to silver oxidation
- Tone shift: fading of the image
Old photos may also have small spots that originates from the development of the negative. These were sometimes removed by the photographer by retouching but this was not always the case. It's not decay and you have to decide for yourself whether to remove these spots or not.
I use Adobe Photoshop to digitally restore my photos. It can be used to repair both physical damage and the color and tone. Restoring with Adobe Lightroom is also an option. The color and tone can be corrected here and if the photo has little damage, it can be repaired with the Spot Removal Tool. Lightroom is not suitable to repair more complex damage. In this article I use Photoshop to illustrate the restoration process. To follow the steps in this article, I assume you have a basic understanding of the Photoshop concepts such as Layers and its tools like the Healing Brush, Clone Stamp and Patch Tool. You can find an overview of all tools and their use on the website Photoshop Essentials.
Scanning the photograph
To start your restoration project, you'll need a good scan of the photograph. I recommend a scan resolution of at least 300 dpi, but preferably 600 dpi, as this gives more room to zoom in during the restoration and you can make a larger print of the final result. Choose a bit depth of 48 bit (16 bit per RGB channel) and save the file as a 16 bit file, like a 16 bit TIFF. Choose Adobe RGB as output color space. If your photo is a glass plate, I recommend to read my article Scanning Glass Plate Negatives and Positives first.
This photo was taken by the French photographer Jean Agélou and dates from around 1910. He made erotic photos and sold them as postcards and stereoviews. As you can see, this photo has quit some damage and it's a bit faded. It's therefore very suitable for our restoration project.
Restore physical damage
Open the scanned file in Photoshop to start the restoration. I create Layers based on the type of adjustment or complexity of the restoration action. This keeps the original scan untouched and I don't have to start all over again in case of mistakes. My workflow starts with restoring physical damage and then I correct the color and tone.
I start by removing small spots and scratches that are easy to remove with the Healing Brush Tool. I create a new layer and zoom in to 200%, select the brush and set the size. I'll start by removing the most obvious damage. As you zoom in further, you will see more spots and other damage. You'll have to decide for yourself how far you want to go with removing physical damage, depending on what you want to do with the final result. For publication on a website in a low or medium resolution, it's sufficient to restore only the major damage. If you want to make a print, you want to go a step further.
For more complex restorations I use the Clone Stamp Tool which has more options to tune, but also requires more skills to use it properly. For larger damaged areas you can use the Patch Tool. You select the damage and drag the selection to an area which will replace the damage. The Patch Tool works well with smooth backgrounds or skies. To use the Clone Stamp Tool and Patch Tool with layers you'll have to enable the option Sample All Layers.
Restore color and tone
When all damage has been removed, I'll adjust color and tone. As mentioned, most vintage photos have an overall yellow color cast caused by exposure to light. You can remove the cast by reducing the saturation of the Yellows. I'll add an Hue/Saturation adjustment layer and reduce the saturation. The photo in this example has just a slight yellow color cast, so I'm reducing the saturation by only -10.
Silver oxidation can be recognised by a blue/purple tint, usually present in the dark areas of the image. If present, you can restore this by reducing the saturation of one or more of these colors: Blues, Cyans and Magentas.
To fix the loss of contrast by fading I create a Levels adjustment layer and slightly increase the contrast by bringing the shadow and highlight sliders closer together. Again, don't overdo. This is a 100 year old photo that does not have the high contrasts that we're used to today.