You should retain a copyright attorney to review all of the facts before you sell, display, distribute or post any pictures. There is much, much more that needs to be known before an attorney could render an opinion on the matter.
There are at least three different issues involved:
Issue #1 Copyright: If the artwork that you are referring to was created by others and NOT you, then either they or the Company or production by whom they were employed or commissioned to create the work owns the copyright in the images. If you reproduce, distribute and/or sell photographic "copies" of that work, then you may be infringing their copyright. [You may have a distinct right to sell the "original" photograph you took - under the "first sale doctrine" - without making and selling additional copies. More information would need to be known before I would even go that far, however.]
Issue # 2: Privacy Rights: The individuals in the photographs have the right under the laws of most states to prevent the use of their images for commercial purposes without their express written permission. So, even though it sounds as though you may own the copyrights in the photographs, you still may not be able to copy, post, distribute or sell the photographs without the written consent of those who appear in them.
Issue #3: The film or production Company has undoubtedly created its own publicity campaign for the movie, complete with stills, trailers, advertising, etc. There is a possibility that it would view your release and sale of your photographs as interfering with its publicity campaign, casting the movie or its actors in a false light, and/or implying that your photos are officially associated with the movie or "sponsored" by the film Company.
You need to review ALL of the facts surrounding the matter with competent IP counsel before taking any action. You might be able to obtain the consents or licenses you need to proceed, but you certainly can't proceed without them.
Disclaimer: This answer does not establish an attorney-client relationship or constitute legal advice. It is for general informational purposes only.
Even if you didn't sign a "non-dislcosure agreement," It seems unlikely that you weren't asked to sign a contract which limited what you allowed on set for and who owned the photos you were hired to take.
It's also likely that what you did sign acknowledged the "publicity" rights of the movie stars, but even if it didn't, in CA celebrities own the exclusive right to exploit their own images, with the only exceptions being for news and sports events.
There is also a copyright issue with regard to the artist's art, since they would own the photos of their art, as derivative works, even if that art was destroyed. They may have assigned the rights to the producer or studio who owns the film, but either way, those copyrights aren't yours.
See an entertainment lawyer before you attempt to do anything with these photos.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.
No. Absolutely not. You will likely be sued if you do this. Even if you did not sign a non-disclosure agreement, you are obligated to honor intellectual property rights of others. Your photographs are derivative works---works that depend on taking advantage of intellectual property and other rights owned and createc by others. You have to get permission to sell derivative works.
You say that you were given permission to take "camera still photos". But is this grant of permission in writing? Was t made by someone who has authority to grant you these rights? Was there an agreement as to the use you could make of the photos? Absent written permission from the studio (by someone with authority to grant permission), the actors, the creators of the art-work that you photographed and probably several other people, you cannot exploit these photographs commercially without running the risk of an expensive law suit.
No. Don't bother hiring a lawyer to advise you on this. What you created during your employment, (even if not within your job duties), belongs to the employer. Either you were a statutory employee, or worked under a "work for hire" contract. Either way, you're not able to exploit the photos. Also.. the artwork belongs to someone else, so your copies amount to copyright infringement.
Don't do it.
I agree with the responses that say you should not do this though I disagrre with some of the reasons given. Since you had no contract, it is not likely a "Work for hire" as you were not an employee of the company but rather an independent contractor. The main reason you should not sell the photos is that they were not paparazzi style pictures taken of celebrities while on public streets or in the public view. Therefore the celebrities and thos in the images have a right to control their publicity and their privacy and California has strict laws relating to that. The best response was the first one: contact an IP lawyer in your area and get a full opinion to assess the maximum use you can make of the images (if any).