The camera settings only save it to the phone or the internal virtual SD card. I have installed a 32 bit hispeed SD card. How can you force it to save in the external SD card?
It varies from phone to phone, but generally in your camera settings you can set a destination. If that's not an option, you can try something more creative with an app such as tasker to have it automatically move pictures that your camera adds to its folder to a different folder on the SD card. If your stock camera app doesn't let you though, there are solid camera apps on the play store that certainly do.
I have Android 6.0 with the standard Camera app. The storage setting is in the half circle control band that appears when the display is stroked slowly from the left. The setting is via an SD card icon on the band. Rotate the band with a finger to find the SD icon. I tested this and it really does change the storage location.
If you go to
Settings you should see
save to device or
save to internal card
I have these options on my Samsung Galaxy Note III
It depends from app to app, if the camera app you are using provides you the option or not. If the camera app that you got with your phone does not have such option, you can try other camera apps available in play store.