Circular Polarizer
- Thread starter koayst
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Hey, i read up on Circular Polarise recently. Maybe the thread link below can help u to judge the difference. Try aiming at blue colour stuff. 
http://forums.clubsnap.org/showthread.php?t=210576&highlight=circular+polariser
http://forums.clubsnap.org/showthread.php?t=210576&highlight=circular+polariser
have you made sure the polarizer is screwed on tight?
It could be you're turning the whole filter instead of the relevant portions
The most significant difference you see out a polarizer is a bluer sky or less reflections on a reflective surface like water. If you are turning it right, the image you see should go darker then brighter as the light is filtered through the polarizer
It could be you're turning the whole filter instead of the relevant portions
The most significant difference you see out a polarizer is a bluer sky or less reflections on a reflective surface like water. If you are turning it right, the image you see should go darker then brighter as the light is filtered through the polarizer
U can try these:
1) Try pointing yr camera at the sky with some clouds. Turn the CPL until see the sky becoming bluer and the clouds become more contrast. The effect will peak at a point and turning it abt another 90degrees will make the effect at its mininum.
2) U can also try it on some surfaces with reflection like a glossy magazine cover. Reflection will be supressed by a certain amount.
3) To test if yr CPL is working, u can try just placing the CPL in front of yr computer's LCD monitor and turn the CPL. It shld almost black out at some point.
Hope these helps. Happy shooting!!
1) Try pointing yr camera at the sky with some clouds. Turn the CPL until see the sky becoming bluer and the clouds become more contrast. The effect will peak at a point and turning it abt another 90degrees will make the effect at its mininum.
2) U can also try it on some surfaces with reflection like a glossy magazine cover. Reflection will be supressed by a certain amount.
3) To test if yr CPL is working, u can try just placing the CPL in front of yr computer's LCD monitor and turn the CPL. It shld almost black out at some point.
Hope these helps. Happy shooting!!
thot only linear polariser need to rotate?
circular, with and w/o shld be able to the reduced glare liao... no need to turn right?
polariser reduce glare? :dunno:
and yes, circular have to rotate as well, if not why they make it that way? :dunno:
yes, you rotate the filter to see the effects, if you don't see any effects on the scene, means the filter won't work here.
circular won't work if there is no blue sky (cloudy), or
blue sky but the sun is in front or behind you.
it also won't reduce reflection on metallic surface , hotspots
It will only work if you are aiming at lights that are polarised. If the scene has no polarised lights, you will not see a difference.
Try it out on windows or car windscreens under the sun. You will see the reflections disappear and reappear as you turn the polariser.
As for sky, if you have a clear sky and with the sun at the low position (morning or evening), the effect is greater. Have the sun at 90° to your shooting direction (pointing your L/R should toward the sun), you will see greater effect of the polariser. Observe the colour of the foilage and the sky.
BC
Linear and circular polariser refers to the plane of polarisation. It does not mean that you do not turn the circular polariser. If you are interested what it means by plane of polarisation, you can read the article in the following link. I've gave up trying to understand it while I was in school.
http://en.wikipedia.org/wiki/Polarization_of_light
BC
Since we are on this topic, can anyone please advise me on the followings:
1. Should a UV filter be used with a Circular Polarizer?
2. Do I have to take out my Circular Polarizer when using ND filters?
3. If Circular Polarizer and ND filter are used together, does it reduce the quality of the picture?
Help!!!
1. Should a UV filter be used with a Circular Polarizer?
2. Do I have to take out my Circular Polarizer when using ND filters?
3. If Circular Polarizer and ND filter are used together, does it reduce the quality of the picture?
Help!!!
1. In DSLR, UV filter serves no purpose other than protecting the front element. It can cause vignetting on some lenses, especially wide angles, if you stack the filters.
2. You decide. It depends why you want to use both together. If you want to further cut the light after putting on the CPL, it can be done. Vignetting can occur if you stack filters on some wide angle lenses.
3. Any extra stuff added to the front of the lens will degrade the image quality. More or less or detectable or undetectable degradation depends on your filter quality.
BC
An easy way to understand linear polarisation. Suppose light is a vertical wooden plank, while the polariser is a net that goes in one direction (either vertical or horizontal). When the net is aligned vertically, you'd find that the wooden plank is able to pass through the net easily, but when the net is aligned horizontally, the plank will be blocked by the net. That's roughly how the linear polariser works. The circular polariser is much more complicated.
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