Why would you presume his child relations are incapable? I was disparaging the suggestion that thousands of dollars of photographic equipment (when the original request was for low budget options) was a priority to obtain data, rather than a smaller investment so the children in his family could share their adventures and explore a potential hobby, rather than be denied the opportunity because thousands of dollars of expensive single purpose equipment are involved.
If a small investment induces a desire in a child to pursue more, that will become clear, and the question will change. Fostering curiosity has nothing to do with "dumb" or "science", it's about growing, exploring, perhaps about birds and airplanes instead of stars, but inexpensive child appropriate tools are more useful to begin with, an individual, child or otherwise, will request better tools if there is sufficient interest.
When the kids lose interest, a digital camera can be re-purposed readily.
PS: Giving a child a microscope ... "unless you help her do actual scientific experiments, she's going to miss most of the value". I disagree entirely, but it depends what you value. You obviously care about data--but we don't know what types of children are in his family. I'd give a child a microscope so she could grow, foster curiosity, witness beauty, discover, expand her horizons, and develop into a more well rounded person. These things work regardless of the type of personality, if she's more an artistic mind, salt is beautiful under a scope, if more about data, there's the online citizen science project to count tumor cells affected by medications. But these things are discovered from the broad exposure, not one specific application afflicted upon the children.