Polarized Filter Who Use Them?

stewart_photo · 06-21-2007, 12:02 AM

Originally posted by mattdm

I haven't done a comparison myself, but as I understand it, linear polarizers inherently have a stronger effect.

I don't see why there would be a hugh difference in the polarizing effect. As I understand it, both contain the same polarizing layers, with the circular containing an additional layer, called a quarter wave retarder, which re-scatters some light in a uniform manner (uniform regardless of which angle the filter is turned to) to benefit the camera's metering system. A linear polarizer, on the other hand, could work at cross purposes with the camera's beam splitter, potentially reducing the amount of light reaching the meter (resulting in slight exposure errors). These errors may not be noticable until the filter is turned to angles opposite (or approaching that) of the beam splitter.

stewart

blende8 · 06-21-2007, 03:11 AM

I think it is good to know and to tell that linear polarizers work, because many of us still have linear ones from their film days.
Perhaps there also is some marketing strategy behind this, that all people switching to digital now have to buy a circular one?

Mark Castleman · 06-21-2007, 04:51 AM

The reason that circular polarizers are recommended does not deal with the digital sensor but rather with the autofocus and metering. Autofocus systems and internal meters use partially polarized light to work and a linear polarizer interferes with this. A circular polarizer has a retarder on the back side to "de-polarize" the light to compensate for this.
This comes from the the Kodak Digital Photoguide.

**SCGushue** · 06-21-2007, 09:11 AM

Originally posted by ChrisA

Ah yes, the old "circular vs linear" debate.

Received wisdom says that CPs are needed to ensure that the AF and metering work with modern cameras.

Well, with the K10D, LPs work just fine.

I can't vouch personally for the K100D. But maybe worth a little investigation before assuming that received wisdom is completely accurate.

Yepper!

LP's work just fine on the K100D. Like any polarizer simply make sure that you never use it at the extremes of either dark or light. Rotate it to the center point between the extremes for the smoothest transition when doing sky shots.

Stephen

jaws · 06-21-2007, 01:40 PM

I use a Hoya HMC CP filter on one lens and need to buy another for a new lens which is 77mm, but why are they so expensive! a new filter is in the mid to high $200's a third of the cost of the lens for a piece of glass , yes a good piece of glass non the less but are the filter manuf having a lend of us?

Cheers,
John

stewart_photo · 06-24-2007, 03:09 AM

Much of the time, based on how polarizers are typically used (at fairly sharp angles to the sun with little chance of lens flare as a result), you will not see any great benefit from using a multi-coated (HMC) polarizing filter. Save some money and purchased a single coated polarizing filter instead, such as...

Hoya 72mm Circular Polarizer Glass Filter

Single coated polarizing filters have been used for decades by many millions of photographers, and there is no special reason (unlike circular over linear) for that to change with digital cameras.

stewart

SupremeMoFo · 06-24-2007, 03:40 AM

US$64.50 for a 72mm?? Ouch - I paid AU$79 (US$66) for a 77mm Hoya, and that was from a shop.

stewart_photo · 06-24-2007, 07:55 AM

LOL. B&H doesn't have the best prices on filters, but is a popular company due to their reliability. If lowest price is more important, one can pick up the same Hoya filter from Adorama for about US $30...

Amazon.com: HOYA 72mm Circularizing Polarizing Filter: Electronics

If one shops around, it might be found at an even lower price.

stewart

PDL · 06-24-2007, 05:42 PM

I bought a CP for my SF-1 and it's Tokina 28-70mm. Behold it is the same size (52mm) as the Pentax Kit and 50-200mm.

I used it extensively during my vacation on all three lenses and my *ist Ds. I have used it on my K10D also. I had one shot out of hundreds that I had to adjust the focus on using the *ist Ds (I use the OK button to focus with the center AF point - exclusively).

To gain maximum sky effect shoot with the sun at 90 degrees - i.e. off of one of your shoulders. Turn the filter for the darkest sky then expose for the highlights - works like a charm on digital cameras.

PDL

axl · 06-26-2007, 08:33 AM

Certainly get a polarizer, It's must have, I was wishing to have one for a while, but luckily I bought it few months ago...

for landscapes certainly take some ND and ND grads too, they will be handy

EdZarts · 06-26-2007, 11:23 AM

I also think a polarizer is a virtual necessity. *especially* on vacation/travel when you may find yourself photographing in blazing sun/near water etc... The polarizer not only cuts down light (probably a 1-2 stop reduction) but helps with glare too. I always have one with me :-)

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06-21-2007, 12:02 AM	#16
stewart_photo Veteran Member Join Date: Apr 2007 Location: Heidelberg, Germany Posts: 1,864	Originally posted by mattdm I haven't done a comparison myself, but as I understand it, linear polarizers inherently have a stronger effect. I don't see why there would be a hugh difference in the polarizing effect. As I understand it, both contain the same polarizing layers, with the circular containing an additional layer, called a quarter wave retarder, which re-scatters some light in a uniform manner (uniform regardless of which angle the filter is turned to) to benefit the camera's metering system. A linear polarizer, on the other hand, could work at cross purposes with the camera's beam splitter, potentially reducing the amount of light reaching the meter (resulting in slight exposure errors). These errors may not be noticable until the filter is turned to angles opposite (or approaching that) of the beam splitter. stewart

06-21-2007, 03:11 AM	#17
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521	I think it is good to know and to tell that linear polarizers work, because many of us still have linear ones from their film days. Perhaps there also is some marketing strategy behind this, that all people switching to digital now have to buy a circular one?

06-21-2007, 04:51 AM	#18
Mark Castleman Senior Member Join Date: Dec 2006 Location: Westminster, Colorado Photos: Gallery \| Albums Posts: 298	The reason that circular polarizers are recommended does not deal with the digital sensor but rather with the autofocus and metering. Autofocus systems and internal meters use partially polarized light to work and a linear polarizer interferes with this. A circular polarizer has a retarder on the back side to "de-polarize" the light to compensate for this. This comes from the the Kodak Digital Photoguide.

06-21-2007, 09:11 AM	#19
SCGushue Site Supporter Join Date: Sep 2006 Location: Pennsylvania Photos: Gallery Posts: 1,449	Originally posted by ChrisA Ah yes, the old "circular vs linear" debate. Received wisdom says that CPs are needed to ensure that the AF and metering work with modern cameras. Well, with the K10D, LPs work just fine. I can't vouch personally for the K100D. But maybe worth a little investigation before assuming that received wisdom is completely accurate. Yepper! LP's work just fine on the K100D. Like any polarizer simply make sure that you never use it at the extremes of either dark or light. Rotate it to the center point between the extremes for the smoothest transition when doing sky shots. Stephen

06-21-2007, 01:40 PM	#20
jaws Forum Member Join Date: Sep 2006 Location: Torquay, Victoria, Aus Posts: 63	I use a Hoya HMC CP filter on one lens and need to buy another for a new lens which is 77mm, but why are they so expensive! a new filter is in the mid to high $200's a third of the cost of the lens for a piece of glass , yes a good piece of glass non the less but are the filter manuf having a lend of us? Cheers, John

06-24-2007, 03:09 AM	#21
stewart_photo Veteran Member Join Date: Apr 2007 Location: Heidelberg, Germany Posts: 1,864	Much of the time, based on how polarizers are typically used (at fairly sharp angles to the sun with little chance of lens flare as a result), you will not see any great benefit from using a multi-coated (HMC) polarizing filter. Save some money and purchased a single coated polarizing filter instead, such as... Hoya 72mm Circular Polarizer Glass Filter Single coated polarizing filters have been used for decades by many millions of photographers, and there is no special reason (unlike circular over linear) for that to change with digital cameras. stewart

06-24-2007, 03:40 AM	#22
SupremeMoFo Veteran Member Join Date: Mar 2007 Location: Queensland, Australia Posts: 668	US$64.50 for a 72mm?? Ouch - I paid AU$79 (US$66) for a 77mm Hoya, and that was from a shop.

06-24-2007, 07:55 AM	#23
stewart_photo Veteran Member Join Date: Apr 2007 Location: Heidelberg, Germany Posts: 1,864	LOL. B&H doesn't have the best prices on filters, but is a popular company due to their reliability. If lowest price is more important, one can pick up the same Hoya filter from Adorama for about US $30... Amazon.com: HOYA 72mm Circularizing Polarizing Filter: Electronics If one shops around, it might be found at an even lower price. stewart

06-24-2007, 05:42 PM	#24
PDL Pentaxian Join Date: Oct 2006 Location: PNW USA Photos: Gallery Posts: 2,128	I bought a CP for my SF-1 and it's Tokina 28-70mm. Behold it is the same size (52mm) as the Pentax Kit and 50-200mm. I used it extensively during my vacation on all three lenses and my ist Ds. I have used it on my K10D also. I had one shot out of hundreds that I had to adjust the focus on using the ist Ds (I use the OK button to focus with the center AF point - exclusively). To gain maximum sky effect shoot with the sun at 90 degrees - i.e. off of one of your shoulders. Turn the filter for the darkest sky then expose for the highlights - works like a charm on digital cameras. PDL

06-26-2007, 08:33 AM	#25
axl Veteran Member Join Date: Mar 2007 Location: Nove Zamky, Slovakia Photos: Gallery \| Albums Posts: 7,183	Certainly get a polarizer, It's must have, I was wishing to have one for a while, but luckily I bought it few months ago... for landscapes certainly take some ND and ND grads too, they will be handy

06-26-2007, 11:23 AM	#26
EdZarts Inactive Account Join Date: Apr 2007 Posts: 26	I also think a polarizer is a virtual necessity. especially on vacation/travel when you may find yourself photographing in blazing sun/near water etc... The polarizer not only cuts down light (probably a 1-2 stop reduction) but helps with glare too. I always have one with me :-)