Limit upload photo file size

I’ve had a good look around but can’t find the specific answer to my problem.

I run a camera club website where it’s members can upload their photographs. I have asked them to keep the file sizes below 200k per photograph but some of them are ignoring the rule and uploading photos in excess of 2mb each. I don’t have a wealth of server space and would like to limit the upload to 200k

Is this possible?