Generally, labs that make optical prints may make machine-analyzed test prints from negatives, but they are usually only in the ball park, and then an operator steps in and makes final corrections. If no operator adjustments are made, the results, at least in my experience, are not so good. The lab does not usually have grays to analyze so must scan a whole negative, strip, or roll. As such the machine alone's quality is quite variable.
Originally Posted by RedSun