The Tate and the National Gallery investigated the use of PTMs and determined that they could be viable alternatives to raking light; especially since PTMs were found to be more easily replicated than raking light photographs.
The Tate investigated the use of PTMs. The National Gallery investigated the use of PTMs. They could be viable alternatives. This was to raking light; especially since PTMs were found to be more easily replicated than raking light photographs. The Tate determined this. The National Gallery determined this.