The error inherent to reading the level of a liquid inside a transparent, graduated container. This can be minimised by taking the reading at as close to the level of the liquid as possible, and applies to reading the level of reagent inside laboratory glassware as well as the level of mercury in a mercury thermometer. This is one of the multitude of errors that can have a bearing on the outcome of an experiment.
This is the difference between the image
seen through the viewfinder
and the image seen by the taking lens
. It is a more common occurence compact
s and TLR
s, and almost unheard of on SLR
s. In this case, Parallax error is more noticeable with close up