You do not need to apply the frango lens to the whole picture, you can crop out a smaller region to get a specific visual effect. Here’s what you do:
- tap the screen; you will see the original picture overlaid in a window in the top right of the frango picture,
- long press on the original picture until you see a pair of blue handles defining the cropping rectangle,
- move the blue handles until you have achieved the effect you want,
- don’t forget to save the picture so your crop settings are saved in the history.
In the picture here the original has been cropped to fit neatly into the pentagon lens.
Cropping a smaller region before applying the frango lens
Original picture by Nick Hopgood via Wikimedia Commons.