Custom Post with custom fields or custom taxonomy

Hi, I’m getting a bit confused about something and would value some advice.
OK I am doing a site for a client which essentially has a section where they want to display a load of photographic images to do with Nature. There is a section on Trees, one on Insects and various others.
I have currently used a standard Post format but wanted to have a filter option whereby the user could just view certain types of trees for example. So I have utilised a plugin to achieve this (Query Multiple Taxonomies), which, as the name suggests, works on custom taxonomies. So I have set up a custom taxonomy for Tree which is hierarchical and for example goes Deciduous -> Tree Type – this displays checkboxes in the widget so the user can for example click on Silver Birch and then the display will show only Silver Birch trees.

Still with me?

Anyway the client has now said they also want to capture other attributes about each photo/post, eg Location, Photographer amongst others. I am unsure whether to add these as custom fields (making a Custom Post to prevent having to add them to each post at a time), or whether I can just extend the taxonomy / create a new one – these attributes will be common across all photos whereas I was currently planning on having a separate taxonomy for each section/type. These new attributes will be something that I think the user will want to filter on (although I can see them requiring to be ANDed instead of ORed – but that’s a separate issue I guess).

I’d appreciate a little bit of guidance here – I’m not massively used to hacking around in the code, I’ve done a bit but am more comfortable using plugins. Thanks.