Welcome to the forum char_lotte. Not dull at all as most of us on here are pedants! However, this is a difficult one and I don't think you can, just as you cannot with (at least the one I've got) a camera. It all depends on the resolution you have chosen etc. Rule of thumb I found on the interweb for a basic feel:
How many pictures can I take on my Samsung Galaxy S?
The Samsung Galaxy S comes in 8GB and 16GB models, which can be further expanded by up to 32GB with a microSD card. As a rough guide,
4GB of internal memory can hold about 1,600 pictures so you’ll be able to take double that if you have an 8GB Samsung Galaxy S. Of course, how many pictures you can take also depends on how much memory space you have left on your handset (you might have filled some of it up already with music or videos for example).
This extract came from here, which looks very useful:
http://community.phones4u.co.uk/the-complete-samsung-galaxy-s-guide/
You can easily find out what's left in the settings. Hope this helps.
