Circular Polarising Filters - Correct Usage...

TheNissanMan

TheNissanMan

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Ryan
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I've bought a C/PL Filter before doing the proper research and have a couple of Q's.

The Filter screws in as a normal filter but the front end rotates freelywith a white arrow on the outer rim, does this mean I can obtain different effects depending on which way the triangle is facing?

If so should the arrow point towards the sun for example?
 
I'll watch this thread with interest as i've just bought one too and havent yet had a chance to play with it.

I was just going to use trial and error and then come on here begging for advice when it all went wrong !! :D

As a partial answer to your question i think it all really depends on the effect you're looking for, hence why they make it adjustable.
 
Attach your filter like normal then look through your camera at your subject, then turn the filter and you will see the sky get darker and lighter, adjust by turning until you are happy with the shot then take the picture,

The purpose of it being able to turn is so you can adjust the frame to darker and lighter, remember if it is too dark it will under expose and need some adjusting post shooting.
I tend to look at the clouds while i turn the filter when they look bright and white i shoot if they go grey then it is too dark.
 
... and remember it's not just for skies.
It also cuts down reflection from leaves and water. Just turn until you get the desired effect. Remember if you surn the camera to portrait orientation you'll have to turn the filter again.

Edit: too slow. :D
 
Thank you peeps :)

Another one of my silly questions well and truely answered!

Give me a couple of months and I'll be able to work through my post history and start a newbs Q&A thread :)
 
Yup and remember if you change your shooting angle in relation to the sun (or other light), you need to adjust again...
 
I am glad this question is on hear & I was just wondering if there is any difference in quality, ie the resuting effect from different C/PL filter manufactures, & which is considered the best? I was comparing a Kood filter I have had for some time againsed a Hoya one, the sky seemed much more blue with the Hoya, allthough it wasnt a very scientific test it may be I was looking through them at different angles & they were different sizes. but it got me thinking
 
LensMarc said:
I am glad this question is on hear & I was just wondering if there is any difference in quality, ie the resuting effect from different C/PL filter manufactures, & which is considered the best? I was comparing a Kood filter I have had for some time againsed a Hoya one, the sky seemed much more blue with the Hoya, allthough it wasnt a very scientific test it may be I was looking through them at different angles & they were different sizes. but it got me thinking
Click to expand...
The thing to remember regarding quality is..buy the best you can afford,no good putting a cheap bit of glass in front of your expensive lens,it will damage the quality of your photo's..this will also apply if you decide you need just a plain filter for protection..:thumbs:
 
Bear in mind also that you can get quite a wide range of stops lost to these things - I've seen anywhere between 1 and 2 but probably you can get even more...
 
Ive always found that using CP filters, if shooting a dramatic sky, you get alot better effect if you point the camera 90degree's from the facing sun...........:thumbs:
 
raider2727 said:
The purpose of it being able to turn is so you can adjust the frame to darker and lighter, remember if it is too dark it will under expose and need some adjusting post shooting.
Click to expand...

Actually thats not true... You are metering through it so your camera should still expose correctly.

You should be looking at the blue bits to make sure that you are getting the maximum saturation (ie blueness)

or looking at the reflective surface to see when the reflections go..

Cheers

MIP
 
Thanks Bob,

6 mins well spent although the guy in the front of the camera comes across as a boring sod, informative though and just what I was after, now going over to DSLR Tips to see what else I can find :thumbs:
 
Don't forget you can always use flash with the polariser - that will give you saturated backgrounds with popped foreground subjects...works really well in certain situations.
 
Another question on this which wasn't answered in the video so hope you can help!

If the weather is like this I'll be off to Cotswold Wildlife Park tomorrow and outside it looks pretty white with only a glimpse of blue in the sky. Could a CPL help turn that white to a more Blue tone or is that just asking for miracles?

Knowing my luck it will be grey, overcast and rainy tomorrow lol!
 
TheNissanMan said:
Another question on this which wasn't answered in the video so hope you can help!

If the weather is like this I'll be off to Cotswold Wildlife Park tomorrow and outside it looks pretty white with only a glimpse of blue in the sky. Could a CPL help turn that white to a more Blue tone or is that just asking for miracles?

Knowing my luck it will be grey, overcast and rainy tomorrow lol!
Click to expand...

Basically, no. A polarising filter works by cutting out polarised light - light travelling in straight parallel rays. That is, light from a clear blue sky, or that is reflected off a (non-metalic) surface which polarises it.

First you need polarised light to start with, then you have to rotate the filter and also position the camera to maximise the angle of polarised reflection - 37 degrees to the surface, from memory.

There is next to no polarised light from an overcast sky. Best to use a graduated filter to darken and/or colour a dull sky.
 
TheNissanMan said:
Another question on this which wasn't answered in the video so hope you can help!

If the weather is like this I'll be off to Cotswold Wildlife Park tomorrow and outside it looks pretty white with only a glimpse of blue in the sky. Could a CPL help turn that white to a more Blue tone or is that just asking for miracles?

Knowing my luck it will be grey, overcast and rainy tomorrow lol!
Click to expand...

That truly would be a miracle.....

Polariser will turn a blue sky bluer (depending on what angle you are to the sun) but keep the clouds white.
 
Polarizers generally add more punch to an image without making it dull and lifeless. Beware of using them on UWA lenses though as you can get 'bandy' effects with skies, particularly when the sun is low.
 
I have a polorising filter and have used it successfully in the past, the lake district was great for it, making the water and sky more punchy.

Though, would there be a huge difference between using it and just bumping up the saturation in PS?
 
dan_yorkshire said:
Though, would there be a huge difference between using it and just bumping up the saturation in PS?
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Yes, because Polarizers block reflected light on a horizontal plane. Take a polarizing filter, go out into the street, and point it at a row of car windscreens - then rotate it. You'll see the reflections disappear and if it's a good polarizer you will be able to see right into the cars.

The saturation going up and giving photos that punchy feel is just a biproduct of the filter's main purpose. If you just want a punchy photo without polarization effects then by all means up the saturation a bit... but polarizers can be really useful, i've taken some cracking pics which otherwise might have been a bit overwhelmed by glare off the water. On the contrary, i've also taken pics which have had to be poked and prodded due to bands in the sky...
 
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