Ive been trying to get a handle on how to enhance black-and-white photos that I find online. For example, the National Archives has hundreds of Ansel Adams photos free for download. But how do I enhance them without washing out much of the detail?Jim Rems, Irvine, California

My first reaction, Jim, is to ask how much you expect to enhance photos that Ansel Adams took. Adams was a master photographer whose Zone technique brought out every bit of detail and contrast in his photosif you're not having much luck optimizing old black-and-whites, it might be because you've chosen Ansel Adams as your subject matter. That's akin to trying to make chocolate taste more chocolaty.

But let's suppose you have a vintage photo that wasn't a product of the greatest black-and-white artist of the 20th century. I suggest that you try optimizing the photo's contrast by stretching the histogram. I've explained how to do so a few times; check out, for example, "." Essentially, through this technique you move the white and black point markers in the histogram to make the best possible use of the light that was available in the scene; it will give you the enhancement you're looking for, and it won't wash out any detail.