iPad videos need to be transferred to my iMac

I have a number of videos that were taken on my iPad of my guitar lessons. I need to move most of those videos to my iMac to free up space on my iPad. It's a 3rd generation iPad, so I don't think Airdrop is usable. I docked the iPad to my computer earlier today, & I can't see these videos. They are not located in photos on the iPad. They are actually found in the camera section which I couldn't see when the iPad was docked. I'm also considering purchasing a new iPad, but need to move these videos to the computer before I can do that. One last thing the iMac is on 10.9.5. Thanks for any help.