Use small amounts of text to give your images context - your gallery pages should be very easy for me to understand. Images should be related to each other so I don't have to spend time figuring out what the images are trying to say.
If you want to show images which aren’t related, group each set of photos under a unique, descriptive heading with copy that tells me what I’m looking at.
Make sure to give me a heading and new copy which describe what I'm looking at - your images should speak for themselves but don't risk me being confused.