As of late I have been taking too much pictures and videos on my iphone and it has been prompting me running out disk space. I remembered that I had deleted alot of these photos and videos already so why do I still have this problem. Then I found out the solution. The thing is that iphone keeps the deleted photos for 29 days. So this means they will still take up memory on your phone until they get purged out of the system after 29 days. So if you want to clear the disk space you would need to go to recently deleted and manually delete those photos that are already deleted.