Not that anyone here on the set was talking about money. His first dino movie may be the highest grossing of all time, but Spielberg will tell you gate receipts weren’t the reason for a sequel. ““I just decided to do it,’’ he said, explaining his f irst directing stint since ““Schindler’s List.’’ ““I had a great time doing the first “Jurassic,’ and if I thought about it too much, I’d talk my way out of anything.’’ Cinematographer Janusz Kaminski helped him have a good time on location. Kaminski (wh o won an Oscar for his black-and-white photography in ““Schindler’’) offered to add a red rose, ““Schindler’’ style, to the carnage of ““Lost World.’’ Spielberg cracked up. One gag from the set actually got into the movie. Screenwriter David Koepp plays a bystander who gets eaten by a T. rex. Given some of the dialogue, he deserved it.