Spain has a culture of appreciation for privacy and even though in areas with a lot of tourism most locals are more used to cameras, rural area residents will likely react defensively.
Can I Shoot Footage in Public without Consent?
No, if you take a picture of somebody in public, you will have to ask them for permission if they are recognisable. You can still shoot in public since you have a freedom of panorama, if photographing landscape or a building and they're in the shot. Actually shooting a street portrait will require permission.
The Spanish constitution, Section 18 reads as:
The right to honour, to personal and family privacy and to the own image is guaranteed.
Can I publish Photos taken of Strangers without Consent?
No, you can not publish pictures of strangers without their consent.
Can I use Street Photos commercially?
No, not for private or commercial purposes, you will need permission.
- in 2015 a woman was fined 800€ for publishing a picture (including license plate) of an illegally parked police car. Source: Evening Standard This was possible due to a controversial law change that can prohibit photographing on duty police officers.