When I run courses/workshops many people ask me what filter would I invest in on a limited budget. Without fail I always reply that a polarising filter is the one to get. Why? Because it is SO useful! It cuts out reflected light form the scene, only capturing the ‘straight line’ light landing on the subject and not the ‘wavy’ reflected light coming off it.It also allows you to see to the bottom of a stream, river or lake as the reflected light off the surface of the water is blocked. It cuts out and/or reduces reflections off glass, metal and other shiny surfaces. It also slows down exposure times so can help in introducing controlled blur into flowing water – waterfalls, streams etc. Versatile, or what?!
There WILL be times when you may well WANT reflections as a key part of your shot. Fine! Just turn the outer ring of the polariser to its non-reflection reducing position – this is a WYSIWYG filter so you will see what you get via the viewfinder or if using live view, on the screen. Be sure to turn the outer revolving ring in the same direction that you screwed the filter in – anticlockwise looking down onto the lens. To turn it the other way MIGHT unscrew the whole filter – and send it crashing to the floor.
1. the polariser, if pointed at a landscape, will always give the best results when the lens is pointing at 90 degrees to the sun – so the sun needs to be to your left or right.
2. when buying a polariser always specify a circular, and NOT a linear, polariser.
See the results below for the effect a polarising filter can have on a landscape. Both taken in identical light with the sun to my left.
The top shot is with the polariser turned to maximum effect. The lower shot is with the polariser turned to allow reflected light through. See the difference?