How to move photos from my phone storage to an SD card?

[AC Question]

I have an android s4 and I can't figure out how to move pictures from my phone to my sd card. My new pictures automatically save to the SD but not any of the old ones.

 

[STARGATE]

Choose all the pictures and videos you want to transfer, click on menu and click on "move to" than choose the place you want them transferred to.