Yep, that's right. A little film warpage, though it can be as much or maybe a little more than the thickness of the emulsion(s) doesn't really cause major decreases in sharpness.
Another point that hasn't been mentioned here (at least I haven't seen it mentioned) is that depth of focus/field operates to a certain degree at the film plane, as well as in front of the lens. I'm pretty sure that the order that the color emulsions are "stacked" onto the film backing take into consideration how different colors of light are affected by a "standard" or hypothetical lens. The film makers have been making film for a long time now. I'm sure that all the points we've considered have been considered by them, too. Len --- - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
