So... I've got a Circular Polariser

John Lindsay

John Lindsay

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John Lindsay
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How does it work?

It's a Hoya one, and turns round at the front after its screwed onto the front of the lens.

I put it on and took shots with the white mark at N,E,S and W as it would appear on a compass, and noticexd no difference.

I just put it on top of my UV(protection) filter, which I now realise may have been a mistake.

Anyone able to shed some light on this?



John
 
Look through the viewfinder as you turn the filter, then you will see the difference. Probly needs to be quite sunny to get the full effect or try looking at a reflection in a window as you are turning it.
 
You'll see the most dramatic effect if you point the camera at 90 degrees from the sun, look through the viewfinder and turn the ring. Use it to deepen the blue of the sky and cut through reflections from water.
 
I realise that it's effects are best seen on a blue sky, and thats what I was shooting at, as it was the first time the sun had shone it what felt like months!

However, as I say, I took 4 shots, and noticed no real difference.

If I actually saved them I'll post them up after work.

Cheers for now.


John
 
John Lindsay said:
However, as I say, I took 4 shots, and noticed no real difference.
Click to expand...

I reckon taking 4 shots at 90 degree intervals is unlikely to show the effect. From my playing with a CPL the effect seems to be over quite a small angle, probably 10-20 degrees?. Also it appears to me that the effect is repeated at 180 degree rotation. Therefore if I'm right :eek: you only took 2 shots and you probably missed the correct angle on both.

Just hold the filter in your hand (no camera or lenses) and hold it up to a blue sky, with the sun to either your left or right side, rotate it slowly and watch.
Try again (without camera) but looking at car windows which have strong reflections.

I must admit my (cheap kood P series slot in) CPL isnt as effective as I would have liked, but I'm not really sure if its the quality of the filter or the way I use it.
 
If you're reading this on an TFT monitor, hold your filter up in front of it and give it a twist...
I know it won't help you practically, but at least it'll prove you've not got a duff CPOL! And it's pretty cool :LOL:
 
I've done cross polarization and things like that in college, (making cassete tapes and plastic cutlery shine the colours of the rainbow)

Just wondered if, as wookie has said, that there would be some form of repitition, and now looking at the shots I have, this does seem to be the case.

If the sun ever comes out again, I'll give it another bash.



John
 
Look through your viewfinder whilst looking at your monitor (assuming its an LCD type) and you will see how it works and how narrow degree the effect is
IMG_0938s.jpg
 
Dust lol, its an excellent way to show up how dirty the screen is
 
It won't mount backwards, of course, but a circular polariser won't appear to do anything if you're holding the threaded side away from you. It only works one way round.
 
Thanks Gofer, and everyone else who has replied, thats a good link, and it looks like my best bet is just to get out there and play with it.


Cheers


John
 
It's a well known fact that polarisers don't work in this country. You need to visit the Med for a few days to test it out. :D
 
silverJON said:
It won't mount backwards, of course, but a circular polariser won't appear to do anything if you're holding the threaded side away from you. It only works one way round.
Click to expand...


ooooohhhh :eek:

that may explain some of my problems with it!

mine's a slot in type for a cokin P holder and I often try it handheld without the holder

:bang: :bang: :bang:
 
silverJON said:
but a circular polariser won't appear to do anything if you're holding the threaded side away from you. It only works one way round.
Click to expand...

I beg to differ here Jon, I've just been out in the sun with mine and it works fine both ways round, but I'm ready to be educated, why wouldn't it work? Of course it won't fit on the lens the wrong way round as you say.
 
Chuckurbarla said:
I beg to differ here Jon, I've just been out in the sun with mine and it works fine both ways round, but I'm ready to be educated, why wouldn't it work? Of course it won't fit on the lens the wrong way round as you say.
Click to expand...

My filter definitely only works one way round. When it's the other way round, turning it barely affects the image - and it makes it go all weird and brown.

I've been studying circular polarisation briefly in my electromagnetic optics course, and there's a reason why it only works one way, but I think I slept through that lecture, so I can't really remember why...
 
Mine only works one way with only a slight effect the other way
 
So lets see your With/Without shots to see what kind of difference people achieve.

This is all ive got, ive since lost my 77mm Hoya pro1D CPL and not yet replaced it.

CPLsplit.jpg
 
mine has the thread for the lens only on one side but I can turn it around and hold it and it will give the same effect either way round.
 
Just tried this myself and mine only works one way round, holding it the other way just produces a slight colour shift as it turns.
 
I'm wondering, those that can turn the polariser over and it works ok . . . is it a linear polariser?

just asking because there was a thread recently that somebody appeared to think it was a circular polariser because it was round and screwed onto the end of the lens, rather than the method of polarising
 
try looking at a tv with it. I didnt notice the difference till yesterday same prob as you but as soon as i did. I could notice the difference with the clouds ans reflections. just to show it works (MAY SOUND STUPID)
 
OK here's a couple of the pool with and without polariser. And yes, now it is warm enough to use I will be cleaning it out!

With polariser
IMG_3661.jpg


Without Polariser
IMG_3662.jpg


These are fairly self explanatory, I'll post some pictures later showing the effect on the sky which is sometimes very disappointing.
 
Another couple of examples (although the examples in previous posts show the difference well enough) :

With:

Pol.jpg


Without:

Non-Pol.jpg
 
Time of day makes a big difference to how well a polariser works on the sky. As mentioned above it works best when the sun is 90 degrees to where you are facing the camera - but that is 90 degrees to the left or right of you... not overhead. So if you go out in the middle of the day the effect will be slight. Late afternoon and it can be dramatic.
 
Once you start to actually get used to it you will find yourself overpolarising scenes all the time in things like late evening shots.
 
30psi said:
Is overpolarising a bad thing though?
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Depends if you like the effect - usually I do


This one was from Canada last year. The dark sky in the middle is down to the polariser. Without the polariser the bright sky would have spoiled the exposure. I could have used a ND grad filter but prefer this even if it is uneven :)

117jasp04.jpg
 
Thats a great shot.

I think some people would say this shot I took in Paris last month is overpolarised:

2270178686_e35512cb8e.jpg
 
Overpoliarsing stuff really depends, some people like it some people dont.

I dont mind it but I am always very concious of it as i dont want to ruin a possibly good shot.
 
Here are two more, with and without again.


With
IMG_3655.jpg



Without
IMG_3656.jpg


I prefer the second of these. Personally I don't like to overdo it too much, although having said that in Robert's nice landscape it does look ok. Living here it becomes a pain having bright strong sunlight 300 days a year and I find myself using a grad to control the sky much more than a polariser. I use the polariser often when shooting in portrait orientation because the colour gradient is minimised.

I have a question though, all my polarisers have PL.L. on the rim, not CPL. Could they be linear not circular? I don't have any trouble metering or auto-focusing with my cameras. Suggestions gratefully received.
 
are you folks with the deep dark skies using expensive polarising filters? or do they all have the same effect?
I'm honestly struggling to see much change with mine (cheap kood), even with the sun low and at 90 degrees. There is a change, clouds get a bit fluffier, but nothing dramatic.
 
Well mine have been cheap enough Wookie. I see that good circular polarisers cost upwards of £50 but I've never paid more than £10, that's why I'm starting to think that mine are all linear ones. But I've been doing a bit of reading and it is said that linear polarisers cut out too much light for auto metering and auto focusing and I don't have any trouble with that so I'm a bit puzzled :thinking:.
 
Chuckurbarla said:
I have a question though, all my polarisers have PL.L. on the rim, not CPL. Could they be linear not circular? I don't have any trouble metering or auto-focusing with my cameras. Suggestions gratefully received.
Click to expand...


PoLariser.Linear.

You may not have any trouble... people say that there are problems but I've never heard of anyone actually using a linear polariser and experiencing them first hand.

Also - circular polarisers can be hideously cheap anyway. I bought a few 72mm ones for £10 each from Curry's clearance table, and plan to 'Bay them when I remember.

I wouldn't worry. If it works, it works. But the evidence ('PLL' and reversability) suggests to me that you have a linear polariser.
 
silverJON said:
PoLariser.Linear.

You may not have any trouble... people say that there are problems but I've never heard of anyone actually using a linear polariser and experiencing them first hand.
Click to expand...


Thanks Jon, my suspicions are confirmed then.:)
 
John also asked "I just put it on top of my UV(protection) filter, which I now realise may have been a mistake. Anyone able to shed some light on this?"

I would also like to hear if this is OK.
 
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