Somebody wrote: > Do I need to over/under-exposure slides as some sort of general rule?
Hi, The general rule for >>PRINT<< film is to expose for the shadows and develop for the highlights. The general rule for >>SLIDE<< film is just the reverse -- that is, to expose for the ~highlights~, but develop for the shadows. "What's the reason for this, and how the devil does one remember?", you might ask. Maybe it would help to think of it in the following manner. The scene you're shooting spans a range of luminance values, from very bright to very dark. One end of this range is going to show up on your emulsion as an area of low density -- that is, a nearly transparent area on the developed emulsion. (For negative film, very dark areas of the scene show up on the developed emulsion as low density. For slide film, very bright areas of the scene show up on the developed emulsion as low density.) The "rule" means that you don't want this low-density area of your developed emulsion to be absolutely transparent -- if it ~is~ transparent, that means you've lost information in the process of recording your scene. This "rule" tells you to set your exposure such that this extreme end of the luminance range shows up on the developed emulsion with "a little bit" of optical density. Thus, to properly capture all the details of dark areas of a scene on print film, you'll need to overexpose a bit. Likewise, to properly capture all the details of light areas of a scene on slide film, you'll need to underexpose a bit. Short answer -- You're best off to get a spot meter and meter exactly. However, if you have to err in your exposures, you're better off slightly ~over~ exposing print film, and slightly ~under~ exposing slides. Keep in mind that print film will be more forgiving due to its greater latitude. Hope this helps somewhat. Bill Peifer Rochester, NY - 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 .
