I can understand that a 25ASA film will be less sensitive to exposure errors expressed in units of time than a 200ASA film is, all else being the same (which it may not be if we're talking night photography, because they may have different reciprocity failure characteristics). But this is because for the same aperture, you need longer times with a less sensitive film, so adding one unit of time will mean less in percent of total time.
But doubling the exposure time increases the light absorbed by the film with 100%, irregardless of how sensitive it is. If someone says 25ASA films in general have a wider latitude than 200ASA films I'm willing to believe it, as I don't use such slow films. -> SPORRS: 'Serious Photographers Of Railroad Related Subjects' -> Web Site: http://www.anet-stl.com/acphotog/sporrs/ -> Message © 1998 SPORRS® - All Rights Reserved
