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erisindevon
08-07-2006, 10:34 PM
I used a circular polarising filter on my 350D today for the frist time, and shot loads of pics at the beach. But the results had pretty poor contrast and all need correcting. Am I doing something wrong? Any tips?

Cheers, Eris
xx
SMAX
09-07-2006, 12:40 AM
It depends on what polarising filter you have. A lot of them are like sunglasses and are very dark when you look at them. This does cut down the brightness and can mess up the exposure settings. Also i take it that you were turning the filter while looking through the lens to adjust the contrast of the shot?
fruitysuet
09-07-2006, 01:36 AM
Oh thanks for asking the question I noticed the same. Smax I take it we should be doing that then? Would be helpful if it said anything to that effect on the packaging.
erisindevon
09-07-2006, 05:47 PM
hahaha - that assumes I have a spare hand - but in fact one hand holds the camera whilst the other is grappling with the toddler....

Okay - I wil try fiddling and see what happens. Presumably for every single shot, as I have a zoom lens - or is the glass itself not 'twisting' as i alter the length? Never seen inside a zoom lens so not sure which bits move....

thanks, Eris
xx
dawnrogers
09-07-2006, 07:06 PM
From what I've read its the filter its self that you turn its not the same shade all the way round......thats right isn't it Smax?? you turn it for the amount of darkness that the shot your taking needs.
ibecks
10-07-2006, 09:57 AM
Yes, as you turn the filter round, the effect will change. Keep an eye on the skies/reflections in the image and you'll see it. Something to do with getting it parallel to the light's wavelength or some such thing!

Some lenses have front elements which twist round as they focus/zoom, but most have now wised up and made sure that the front elment doesn't mess with your polariser.
SMAX
11-07-2006, 08:23 PM
There is also the problem with a lot of auto focus lenses. The filter ring is also the focus ring so it turns as it focuses. The problem then is when you turn the polarising filter it can knock the lens out of focus, only to turn back again as it refocuses when you press the shutter release. Thus putting the polarising filter back to where it was!!!!