As the Nazis took power, his father immigrated to France through Switzerland. But in 1939, while bike-riding from Paris to Brittany, young Clemens saw posters warning non-French residents to register with the local authorities.
Still a German citizen, he was arrested, labeled an enemy alien and sent to toil for three years in sardine and weapons plants, a quarry, kitchens and an infirmary. Then he was shipped to a camp under the control of the collaborationist French Vichy government. There, by chance, he was reunited with his father, and both were ominously identified as Jews.
In 1942, after the father and son discovered that Clemens’s mother and sister were confined at a farm nearby, all four managed to escape with the help of the Emergency Rescue Committee, a private American relief organization, and two family friends: Anna Freud, a daughter of Sigmund Freud, and Princess Maria Bonaparte, a great-grandniece of Napoleon.
The Kalischers took a French freighter from Marseille to Casablanca, Morocco, where they boarded another ship bound for Bermuda and Baltimore. When they arrived in New York, Mr. Kalischer, at 21, weighed a skeletal 88 pounds.
Besides taking classes at the Photo League and using its darkroom, he also studied art at Cooper Union and photography at the New School.
He eventually took his candid photographs of New Yorkers to The Times, hoping for freelance assignments, and was introduced to Grace Glueck, a Times arts editor and critic. So began a 35-year relationship with the newspaper.