Photo studio is what the business is called, everywhere, in plain English. Portrait studios, rental spaces, commercial production facilities, school photography operations, the lot.
Studio rental in particular has grown into a proper market. Photographers book space by the hour through platforms, and the platforms are competing on inventory and discovery. A directory or booking site under this name would be understood instantly by both sides of that market. It also suits a trade association, a training organisation, or an educational resource for people learning studio lighting and setup.
The .org reads well for the community and association side, and it costs a studio-booking marketplace very little, because that kind of business acquires through search and referral rather than direct type-in.
The term has one spelling, no regional variation, and describes a service people pay for in every city on earth. That combination is rarer in available domains than it sounds.
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