Sometimes when shooting or conceptualising a scene, it's hard to visualise composition without actually looking through a specific lens. This new iPhone app shows you just how hundreds of lenses will see your subject.
The app is called Mark II Artist's Viewfinder. Weird name. What it does is simulate frame lines in your iPhone's camera display by accessing a database of hundreds of camera and lens combinations. It's a pretty neat function, especially if you are a very deliberate type of photographer who likes to carefully plan before pulling the trigger. Maybe you are shooting large format and want to size up a scene before lugging all that gear into the field. This could come in handy!
You can have the app record GPS coordinates and metadata about the frame lines you choose, so you can consult each perspective you see later on.
The biggest limitation is that since the iPhone's camera has around a 30mm (35mm equivalent) focal length depending on the model, it can't show you frame lines for lenses any wider than that unless you buy the wide-angle adapter that the company sells separately.