RGB stands for red, green and blue, the three colour ‘channels’ that go to make up all the colours in a digital image. It comes in two varieties – sRGB is a ‘universal’ RGB that can be used and displayed by any device, whereas Adobe RGB is a more specialised alternative for pros.
Random ‘speckling’ in an image caused by variations in the light levels captured by the photosites on the sensor. Noise is worse with the smaller photosites on small sensors and at higher ISO settings generally. You can get ‘chroma’ (coloured) noise and ‘luminance’ noise (general ‘grittiness’) the same colour as the background.
Where the shot is taken with the camera held horizontally – pictures are wider than they are tall.
Using mathematical analysis to fill in the gaps in data. The photosites on sensors only capture red, green or blue light, so interpolation is used to examine surrounding pixels and calculate full colour values from those. When you increase the size (in pixels) of a photo, the software interpolates new pixels from the existing ones.
Depth of field is the near-to-far sharpness in a picture. If both foreground and distant objects are sharp, there’s lot’s of depth of field. If only the subject is sharp and the foreground and background are blurred, it’s shallow depth of field. Both are fine, depending on the effect you’re trying to achieve in your picture. Depth of field is affected by the lens focal length (longer focal lengths produce shallower depth of field), the lens aperture (wider apertures produce shallower depth of field) and focus distance – the closer your subject the shallower the depth of field. Shallow depth of field can product attractive background blur in portrait shots, for example. This is often referred to as ‘bokeh’, though bokeh is actually something slightly different.