was flipping my old law textbooks and see if i can find anything similar.. this post is for people who would like to know a little more, and have time to read my very lenghty post. for your reading pleasure, i have found the online texts of some of the laws and hyperlinked them as i refer to them.
basically, you have 2 kinds of scenarios.. the 1st being the engagement of photography services with a service contract (Scen. 1), and 2nd being that without a service contract (Scen. 2).
For Scen. 1, the terms and conditions within the contract will be legal binding (
Contracts Act - Chapter 53B, Singapore Statutes and the
Sales of Goods Act - Chapter 393, English Acts), as long as the terms and conditions of the contract are not considered "Unfair" (as according to the
Unfair Contract Terms Act - Chapter 396, English Acts), as well as not contravening any other laws of Singapore (or laws adopted by Singapore).
A point to note that in the Sale of Goods Act (note that photography services would be considered as a sale of goods), that in Paragraph 4, Subsection 1, any written or verbal agreement or conduct that implies agreement, shall constitute a contract. So even if your contract has missed out certain points, but you talked about it and agreed on certain terms (which were not put down in writing), the points will be included as terms and conditions of your contract. But of course proving whatever was discussed verbally and not put down in writing will be difficult.
Theoretically, for scen. 1, as long as you have written it in the contract or communicated it in anyway (with agreement from the clients), you are entitled to keep and use the photos. This of course is from a legal perspective and not a moral/ethical perspective.
For Scen. 2, if you have no written contract, as covered previously about verbal and conduct being a form of contract, you might be bound as long as the other party can prove. However, no such forms on "contracts" can be proven, it would boil down to the Principle of Intent, whereby at the request of the person that engaged you, you have provided photography services to the person and received payment (in any form) for the services provided (actually, whether you received payment for it at all is not very important). The act of the provision of photography services at the request of the person who engaged you has automatically formed a relationship between 2 parties (the "customer" and the "service/goods provider"). According to previous cases (hereby we do not use statutes but what we term "case law" which are references to previous judges' rulings), there are "duties" whereby the photographer is hired to take photographs of the client, whereby photographic services were engaged. Hereby the photographer is hired for his services, and finished products are given to the client (either prints or softcopies or film). Unless explicitly mentioned (as in a contract), the photographer has a moral obligation to seek the client's permission for the usage of the photos. In some instances, I have found that judges have ruled mostly in favour of clients who have paid for certain services or goods.
Well, if you're still reading this post and not lost in the legal mambo jambo, please remember that whatever I have written is based on what I remember from my law lectures. This is mechanical. At the end of the day, I personally feel it is best to approach the clients and have them agree to let us use the photos, for reasons of comfort, building good business relationships, as well as just being a nice person. Cheers!