Does anyone out there actually know the 'correct' density of mid gray on a correctly developed B&W negative???

I know this is a pretty anal-retentive question, but it's for a friend (yes, really), so please?

Chris (cg@alphalink.com.au)

-- Chris Groenhout (cg@alphalink.com.au), May 18, 1999

Answers

There really is no "correct" middle grey; there's only the minimum density above film base + fog you want to use for your speed point and there's the CI that suits how you print. There's not even a standard for light-meter calibration.

-- John Hicks / John's Camera Shop (jbh@magicnet.net), May 19, 1999.

John is absolutely right, there is no 'correct' density, it's all about your preference.

However, there is an ISO definition of film speed, which uses a particular CI (Contrast Index), and that gives a Zone V density of 0.80 plus or minus 0.05. But don't think of that as 'correct'.

-- Alan Gibson (Alan.Gibson@technologist.com), May 19, 1999.