There is more over-exposure latitude with larger formats. The less one has to enlarge a negative, the better the quality of over-exposed negatives. In fact the literature indicates that when contact printing, the 'correct' exposure is represented as a plateau, or range of exposures. (See diagram below).
Originally Posted by darkosaric
In addition to the that information is that fact that a hand-held exposure meter won't be able to account for bellows factor or inaccurate leaf shutters, reciprocity failure or a film's specific response to a colored filter.
Furthermore, popular believe is that as development changes (N+1, etc.) there is a change in exposure index. The scientific literature does not support this, indicating the minimum useful density is a point with a tangent about one-third the gamma.
Furthermore, typical spot-meter technique that many large format users entertain is frequently not more than a guess..."lets see I'll set the ISO to 100, I'll base my exposure on that shadow of Zone III...no, under that log is Zone I...No, that shale is Zone II...wait, inside that hollow tree is Zone I...No, I'll use N development so I'll change the ISO to 50...now my digital meter indicates f9.21 thats somewhere here on the paper aperture scale I made for this old Ilex...etc."
In terms of large format, as far as I'm concerned, a 1/3 stop change in exposure reading is insignificant due to multiple other factors of potentially larger magnitude.
Last edited by ic-racer; 05-28-2014 at 07:43 AM. Click to view previous post history.