Q. What is happening to the world of single-lens reflex cameras (SLRs)? Are the manufacturers abandoning them? I realize that point-and-shoots sell more than SLRs, but I hope they are not going to be phased out. And what about manual cameras? It seems that most of the new SLRs emphasize the program modes and some don't even have a manual override. How about cost? It seems that the SLRs aren't getting any cheaper.

A. Single-lens reflex cameras are alive and well and moving toward new and better things.

While it's true that nearly 80 percent of the cameras sold in this country last year were the compact automatics, sales of SLRs are good. All of the major manufacturers have models that are either full manual, such as the Ricoh KR-5 Super II and the Pentax K-1000, or that can be dropped into the manual mode very easily, such as the Nikon 8008.

As for price, the SLRs aren't getting cheaper, but they are holding the line. Their prices don't go up automatically every year. When a new model costs a bit more, we get a lot more for our money. Some companies, in fact, offer special promotions with rebates to lower the purchase price.

HERE ARE two of the best photography videotapes released for the summer:

The first is "150 Years of Photography: An American Image." Not a rehash of old stories, this beautifully produced, one-hour Kodak tape is a carefully edited summation of photography from its beginnings. It is both a history of the nation and a history of photography.

Photography started in the Paris studio of Louis Daguerre when he proved that a permanent image could be captured on a copper plate that had been covered with silver, exposed to light and then "developed" in mercury vapors.

The tape shows how photography developed in America and includes some terrific shots of wagon trains moving west and settlers cooking dinner at day's end.

The Civil War pictures of Matthew Brady, who was just one of the 300 photograhers covering the war, are featured in the videotape. It was the first time the world had a true record of the horrors of the battlefield.

Brutal images of the civil rights crusade bring back terrible memories of violence and shame; Vietnam pictures show the destruction in the battles and the polarization of America.

The last part of the tape is a kaleidoscope of pictures by dozens of America's finest photographers. From Steiglitz to Cancellare, from Brady to Adams, these are pictures you'll want to see again and again.

"150 Years of Photography," a Wood-Knapp Video, is available in photography and specialty stores, or directly from Wood-Knapp at 800/965-3512.

"Ansel Adams, Photographer" is a biographical tour of the places, things and people that influenced and helped perfect the works of one of the world's most respected photographers.

The tape, made just a few years before Adams's death in 1964, gives an insight into the thoughts and techniques of this American master.

The opening scenes are of Adams walking in the meadows of Yosemite National Park, where he took pictures for more than 60 years. We watch as he sets up his tripod, unpacks his 8 X 10 view camera, reads the light, focuses, then snaps the picture.

We listen as Adams tells us that his first "serious" picture was taken in 1927. At that point he was "able to visualize the image I wanted."

It was this ability to visualize, combined with the correct learning of the technicalities of his craft, that led to his zone system of exposure. Adams tells us that he never saw a subject much differently than anyone else, but that he responded differently.

We watch Adams in the darkroom working on a test print. When it's finished, he carries it to the dining room to see how it looks in room light. We see him put a print in the microwave oven, to dry it quickly and to preserve the white tones.

Throughout the entire tape we are shown dozens of Adams' pictures. Many I recognized, some were new, but all were a sight to behold.

"Ansel Adams, Photographer" is a Pacific Arts Video, available in camera stores and specialty shops, and is distributed by Argraph Corp, 111 Asia Place, Carlstadt, NJ 07072.

Write Carl Kramer c/o Weekend, The Washington Post, 1150 15th St. NW, Washington, DC 20071.