Black and white photographs
On occasion, many of my students have brought scans of old black white family photographs to my lectures burnt onto CD. These images are usually scanned using a large variety of applications and nearly always exhibited the same misunderstanding.
If you have a black and white, or sepia photo, scan it in grayscale. If you scan in RGB, or CMYK you gain very little.
- Old photographs using have countless stains and dis-colourations which will need to be removed and balanced. Scanning in greyscale will minimise the effects of such ware and tear.
- A grayscale image only contains 1 channel of tonal information as opposed to an RGB which has 3 channels or a CMYK which has 4. An RGB file for instance, will effectively be 3 times larger than a single channel Grayscale.
What should I do then?
When scanning in a black and white image, use the ‘Gray’, ‘Black and white’, ‘Grayscale’ setting on your scanner’s software. If you have already scanned your image in, then in Adobe Photoshop, click on (menu) Image> Mode> Grayscale.
If you want your image to be Sepia, simply restore or prepare your image in Grayscale mode – when you have finished, click on (menu) Image> Mode> RGB and then call up the colour balance (CTRL and B); dray the first bar a little to the right, leave the centre bar where it is and drag the bottom bar to the left. Drag more or less to increase or decrease amount of sepia tone.