The jury which last January found Eastman Kodak co. guilty of monopolizing the amateur photographic business through its technological dominance yesterday began deliberations on the amount of damages to award Berkey Photos Inc.

Berkey brought the landmark antitrust case against Kodak, seeking $43 million in compensation. Under the federal antitrust laws, whatever the jury awards Berkey would be tripled.

Berkey claims it has been required to pay excessively high prices for amateur film, color print paper and photofinishing equipment purchased from Kodak. It also says it has lost sales and profits it otherwise would have earned in its camera and processing business, and that it suffered competitively because Kodak received discriminatory discounts on flash-cubes purchased from Sylvania and General Electric which it included in its camera kits.

U.S. District Court Judge Marvin E. Frankel, who presided over the six-month trial and the three weeks of arguments in the second phase which began Feb. 21, took nearly two hours to read detailed instructions to the jury of eight women and two men.

The judge told the jury their object was "not to impose a fine or penalty on Kodak, but to determine the amount of compensatory damages owed to Berkey. That is, your verdict must be designed to make Berkey whole by putting it, financially, in the position it would have been in but for the wrongful conduct of the defendant."

The jury was provided with 10 questions for separate determinations of whether damages to Berkey occurred, in the first place, and how much the specific compensation should be in each case.

Berkey, a company with sales of about $200 million a year, filed the antitrust suit in 1973 against Kodak, the worldwide photography, giant whose sales in 1977 totaled $6 billion and net profits amounted to $643 million.