Question about cameras in japan

I was wondering if it's rude to just take a camera such as a DSLR and take pictures or film stuff. I was planning on walking around some big citys and go inside shops because I wanted to share what it's like there with people back in my country. Do you generally need to ask for permission in shops in the citys before taking a DSLR sized camera and taking pictures or would they not mind you doing it?

Please ask permission before taking pictures inside a business establishment. My personal experience is that some businesses welcome your photography while others will politely say "Ie". No. Up scale Kimono shops particularly say no.

Japan is a beautiful country. Lots of other good shots.

Enjoy your trip.

Businesses tend to discourage photography inside their establishments. The possibility of espionage is what they don't want happening. Some companies are quite protective.

Also, I wouldn't take photos of girls handing out flyers in Akiba, any government building, or people without asking for permission. Chances are the girls and government will say no, but the people will probably say yes if asked politely. Of course, candid and long shots will be easy to snap, but if you're up close, asking would be polite.

some business owners are a little crazy about no-photography inside their shops. in those cases you need to respect the rules.

some owners however will try to stop you from photographing on the street - for example around yanaka ginza or shops in sugamo. in such cases photographing from the street is totally legal and you can photograph as much as long as you can stand a crazy shop owner chasing you.

Do all store owners, restaurants etc. in you home country let people take photos of the inside of their businesses? I don't think so!
This is an unwritten universal rule!

Now if a store owner doesn't mind to have his own photo taken and actually ask, as it has happened to me...that's a different story.

Some people will also take a photo of themselves at a restaurant table or ask a staff to take the photo..but it is the custom not to have other customers in the photo...