Section 29B. (a) Whoever, with lascivious intent, disseminates any visual material that contains a representation or reproduction of any posture or exhibition in a state of nudity involving the use of a child who is under eighteen years of age, knowing the contents of such visual material or having sufficient facts in his possession to have knowledge of the contents thereof, or has in his possession any such visual material knowing the contents or having sufficient facts in his possession to have knowledge of the contents thereof, with the intent to disseminate the same, shall be punished in the state prison for a term of not less than ten nor more than twenty years or by a fine of not less than ten thousand nor more than fifty thousand dollars or three times the monetary value of any economic gain derived from said dissemination, whichever is greater, or by both such fine and imprisonment.

(b) Whoever with lascivious intent disseminates any visual material that contains a representation or reproduction of any act that depicts, describes, or represents sexual conduct participated or engaged in by a child who is under eighteen years of age, knowing the contents of such visual material or having sufficient facts in his possession to have knowledge of the contents thereof, or whoever has in his possession any such visual material knowing the contents or having sufficient facts in his possession to have knowledge of the contents thereof, with the intent to disseminate the same, shall be punished in the state prison for a term of not less than ten nor more than twenty years or by a fine of not less than ten thousand nor more than fifty thousand dollars or three times the monetary value of any economic gain derived from said dissemination, whichever is greater, or by both such fine and imprisonment.

(c) For the purposes of this section, the determination whether the child in any visual material prohibited hereunder is under eighteen years of age may be made by the personal testimony of such child, by the testimony of a person who produced, processed, published, printed or manufactured such visual material that the child therein was known to him to be under eighteen years of age, by testimony of a person who observed the visual material, or by expert medical testimony as to the age of the child based upon the child's physical appearance, by inspection of the visual material, or by any other method authorized by any general or special law or by any applicable rule of evidence.

(d) In a prosecution under this section, a minor shall be deemed incapable of consenting to any conduct of the defendant for which said defendant is being prosecuted.

(e) Pursuant to this section, proof that dissemination of any visual material that contains a representation or reproduction of sexual conduct or of any posture or exhibition in a state of nudity involving the use of a child who is under eighteen years of age was for a bona fide scientific, medical, or educational purpose for a bona fide school, museum, or library may be considered as evidence of a lack of lascivious intent.