Washington has become a sought- after assignment among the nation's leading photographers -- press, commercial or studio. In fact, photographers from all over the world strive to work or at least make their headquarters here.

So the competition is fierce. They don't all make it to the top.

One who has is Jodi Cobb, of the National Geographic Society. Cobb is this year's Photographer of the Year of the White House News Photographers' Association.

She won the prestigious award by taking a first place in the Color Picture Story class, second in the Color Pictorial class, second in the Sports class, and an honorable mention in the Color Personalities class.

Recently, she sat and talked about the photography profession, and answered some questions:

Q. How did you become a photographer? Was it a long-time ambition?

A. Actually, I began as a writer, but moved into photography. I studied photojournalism at the University of Missouri at Columbia and worked with Professor Cliff Edom.

Q. What was your first professional photographic job?

A. I worked for the Wilmington (Del.) News-Journal and the Denver Post before starting to work for the National Geographic.

Q. Why did you change from writing to photography?

A. Oh, I think it was the immediacy, the working with people that I liked the most. There was no confinement . . . you weren't stuck behind a desk. I realized that I was a visual person, and that was why I changed directions.

Q. What were your favorite assignments?

A. China and Jerusalem. In China, the best part was knowing that I was seeing things for a lot of people. Seeing things that they had never seen and, for that matter, things that I had never seen. So many new situations. (Her pictures appeared in the National Geographic Book "Journey into China" in 1982.)

In Jerusalem it was the story itself. The passion of the place, the people . . . such an incredible mix of people. I was there taking pictures of the most fiercely contested spot on earth with the chance to see why. I was covering the West Bank during the period of severest unrest since 1967, and just as I was about to leave the country, Israel invaded Lebanon. (These pictures were featured in the National Geographic Magazine of April 1983.)

Q. How long did you spend on these assignments?

A. China was two months and Jerusalem about four months.

Q. Is this normal?

A. Yes, about three months on the average. It depends on the assignment. The subject dictates the schedule. There's generally a three- month lead time for the magazine. From the start of planning to publication it can be about a year.

Q. Do you get to pick your assignments or do you take what's handed to you?

A. A lot of planning goes into this kind of selection. You certainly are aware of stories that are brewing and some of them you lobby to cover. I lobbied for China.

Q. How much say do you have as to which of your pictures are used?

A. A good deal. The photographer's input is always encouraged. We were at the scene and can best answer any questions.

Q. What kind of equipment do you use?

A. I use Nikons. And I try to keep my equipment as simple as possible. The equipment should be used as the medium, and the subject should come through. I want people to be aware of the pictures themselves rather than how I took them.

Q. Do you feel that there is discrimination against women in professional photography today?

A. That's a loaded question. There are some great women photojournalists today, but I don't know why their numbers don't seem to increase very rapidly. Some of the women I looked up to when I was going to school are still the ones mentioned as leaders in the profession.

Q. What are you working on now?

A. I'm working on a story on Palm Springs for the magazine and also some things on the Alps for a book. This makes you think a little. When you shoot for the magazine you deal with specifics, things that are timely; pictures for a book are more general.