Photo: Susana Bates / Special To The Chronicle

A San Francisco ballot measure intended to increase the transparency of who pays for campaign ads won easily Tuesday.

Proposition F, called “Sunlight on Dark Money,” took a strong lead at 76%, and it required a simple majority to pass.

The measure’s passage means campaigns will be forced to more prominently disclose who donates big chunks of money to a cause. The point is to give voters a better idea of who is behind the campaign ads that inundate their mailboxes, social media feeds and TVs in the run-up to an election.

The measure comes as the amount of money spent on local campaigns reaches staggering heights. The local elections in 2018 were the most expensive in recent history, while millions of dollars were spent on this year’s election — despite that there were only a few competitive races.

Prop. F is targeted at independent political action committees, which can raise an unlimited amount of money from corporations, unions and individuals. Those committees can then donate to individual candidate committees, which makes it less obvious who is behind the donations.

Campaign ads now will have to display the names and contribution totals of the top three donors giving $5,000 or more. If any of the top three donors is a committee, the ad must also show the name and the dollar amount contributed by each of the top two major contributors of $5,000 or more to that committee.

Political consultant Jon Golinger, co-author of the initiative, said the measure will also limit “pay-to-play” politics in City Hall by barring campaign contributions from any person or company with land-use decisions going before the city.

The restriction will apply for a year after the proposal is either approved, rejected or withdrawn. It will not apply to contributions toward offices not typically involved in land use decisions, such as the school board.

The measure also prohibits limited liability corporations and limited partnerships from donating to candidate committees.

Trisha Thadani is a San Francisco Chronicle staff writer. Email: tthadani@sfchronicle.com Twitter: @TrishaThadani