Polarizer.

[JohnP]

Just treated myself to a new and hopefully much better Hoya polarizing filter. I have been using a much cheaper polarizer and I have often been disappointed with the results. Talking about filters in general, it has always annoyed me that most filters have the glass held in by a sort of circlip and the glass is never a tight fit and I've often found that dust gets (heaven knows how) on to the back of the filter glass and even the main lens. I don't know if it's only me that has this problem. The glass on my new Hoya polarizar is sealed into the metal frame so hopefully I won't have the dust problem now. The frame is extremely slimline and light weight compared to the old filter, hopefully we will have some nice sunny days with blue skies soon so that I can get to try it out.

http://www.kenrockwell.com/hoya/hd-filters.htm

[Phil]

You can't beat quality stuff.

But shouldn't that be 'polariser'? :innocent:

[Guest DaveW]

Remember if trying to darken the sky with a polarising filter that it will not darken the sky in all directions at any time of the day. Maximum polarisation is at right angles to the sun and the easiest way to find the area of maximum polarisation is to point your index finger at the sun with your thumb straight up at right angles and rotate your hand and the circle your thumb describes is the direction that the polariser will darken the sky the most, so this direction varies throughout the day as the sun crosses the sky.

http://www.cambridge...ing-filters.htm

They don't in fact recommend using polarising filters on wide angle lenses to darken the sky because of this uneven polarisation shown by a wider angle view. Click on the small picture of this in the following link to enlarge the example:-

http://photonius.wik...ces.com/Filters

Phil, regarding polariser v. polarizer. My American spell checker keeps changing the "s" to a "z", simply the usual American v. English spelling differences.

DaveW

Edited November 6, 2012 by DaveW

[colinb]

They don't in fact recommend using polarising filters on wide angle lenses to darken the sky because of this uneven polarisation shown by a wider angle view. Click on the small picture of this in the following link to enlarge the example:-

.

DaveW

whilst this can be true I often use a 77mm circular polarising filter on my 10/20mm wide lens and have never had the poor result shown in the link. on the odd occasion had dark corners but nothing like the sample photo.

[Guest DaveW]

I suppose degree of polarisation may depend on how sunny it is Colin and how much you rotate the polariser. Obviously they will illustrate it with the more extreme examples at maximum polariser rotation to make their point.

http://havecamerawilltravel.com/photographer/polarizing-filter-wideangle-lens

Most extreme examples of unevenly polarised skies seem to be taken in sunnier climes than ours, so are what you may expect on a very sunny day. Also as pointed out earlier it depende if you are pointing your lens at right angles to the sun. If you have the sun towards or behind you the effect will be negligable. That problem of using a polariser on a wide angle only relates to the sky. If you are using it to remove the shine off water etc it will be OK.

DaveW