For more than 25 years, Mark Sennet stood behind the lens for Time-Life magazine. He photographed presidents — from Ronald Reagan, both before and after his Alzheimer's diagnosis, to Gerald Ford and Barack Obama — as well as legendary athletes and Hollywood's brightest stars.

Among the famous faces he captured on film, some stood out more than others. "Robin Williams was one of my favorite people to photograph because he was so open to any suggestions I had for the shoot, and he would take it over the top!"

In his late 20s, while working at the London Daily Express, Mark had the opportunity to travel with and photograph Prince Charles, Queen Elizabeth and Princess Margaret. Years later, he also captured the wedding of Kate Middleton and Prince William, adding another royal milestone to his portfolio.

"One of my favorite photo sessions was with Stephen Spielberg after he won his Oscars for 'Schindler's List.' He asked me to spend the day with him. Another time, I was sent to the set of 'Miami Vice' with Don Johnson, and in the evenings I went out with the real Miami Vice squad to photograph their raids."

About 10 years ago, Mark started forgetting things like his wallet and keys. His wife, Pam, and daughter, Lauren, also started to notice changes. In 2022, Mark had a grand mal seizure which landed him in hospital. After spending a week in a neurological care unit, he was officially diagnosed with Alzheimer's disease.

At first, Mark had trouble accepting his diagnosis, but then became determined to live well with the disease. "I decided I was not going to become a victim. I've kept a positive attitude and I am making changes to my lifestyle, like exercising and keeping my brain active."

A month after the seizure, Mark made it to walk his daughter down the aisle at her wedding. "I wasn't going to miss that!"

The Sennet family first connected with the Alzheimer's Association after a friend gave them the 24/7 Helpline number (800.272.3900) and insisted Pam save it in her phone. One night, Mark woke up confused, and Pam decided to call.

"She was so thankful for the help she received. She felt like she had support at the bedside even though the care consultant was on the phone. Afterwards, the Association directed her to local resources such as support groups and gerontologists," said Mark. "And from there on, our relationship with the Association has only grown."

Now Mark is working with his daughter on a new project — a coffee table book that will contain his past work and the work he's done since his diagnosis. Through this collection, he aims to send a message of hope.

It will include celebrities such as #ENDALZ Celebrity Champion Amara Walker, CNN's Sanjay Gupta, M.D., and other individuals who have been impacted by Alzheimer's. He also hopes to include photos of physicians and researchers working toward a cure.

"Life doesn't have to end with the diagnosis. I have this disease, but I am still shooting and moving my work forward with Pam and Lauren's help. Keep active, keep moving, keep laughing and don't ever give up! I hope my photos will help people smile."