a waterdrop isn't going to look like much headon. it does to our eyes because our brain interprets it and usualy enhances details without our realizing it. but for the camera to see it well you'll need to find a more interesting camera angle, where the light glances off the drop, something behind it distorts where the drop is, and things are reflected in it. Take a close look at image of water drops and study the drops themself. ask yourself why the drops look interesting (ignore the rest of the image for this study). Close one eye while you do this, it makes it eaiswer when studying 3D space that will ultimately be reproduced in 2D, to close one eye.