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Filters: UV or Polarising

 
 
Andrew Brydon
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      02-22-2004

Been recommended both UV filter and Polarising filter, both as
alternatives for a semi-permanent attachment when outdoors.
What are the pros and cons of each, and overall which would be the
better choice? [Local shop only has circular polarisers, if it matters.]
--
Andrew Brydon
Life is just the beta-version of death
 
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Lucas Tam
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      02-22-2004
Andrew Brydon <(E-Mail Removed)> wrote in news:m$7ysveB1DOAFwc6
@isbjorn.demon.co.uk:

> What are the pros and cons of each


UV filters help remove the haze in the sky, helps with landscape
photography. Personally I never noticed any increase in picture quality -
probably due to the fact my camera already has a multi-coating on the
lens. Most people use UV filters as a cheap lens protector.

Polarizers are used to filter out certain wavelengths of lights, thus
Polarizers have the ability to reduce glare and increase the saturation
of blues and greens. A polarizer is great if you want to get a vivid blue
sky or lush greens you see in photographs in magazines or posters. A
polarizer can also be used to shoot photographs through glass or water by
reducing reflection.

In short, a UV filter is useful as a lens protector, a Polarizer makes
your pictures pretty for landscape photography (because there are a lot
of blues/greens in nature).

p.s. some digital cameras may have some internal polarizing... like the
Canon S400. The Canon S400 seems to produce some VERY nice blue skies...
which I don't see on my Fuji S602. On my Fuji, I need a polarizer to
create the same blue sky effect as my S400.

--
Lucas Tam ((E-Mail Removed))
Please delete "REMOVE" from the e-mail address when replying.
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John Navas
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      02-22-2004
[POSTED TO rec.photo.digital - REPLY ON USENET PLEASE]

In <Xns949789969473nntprogerscom@140.99.99.130> on Sun, 22 Feb 2004 05:50:47
GMT, Lucas Tam <(E-Mail Removed)> wrote:

>Andrew Brydon <(E-Mail Removed)> wrote in news:m$7ysveB1DOAFwc6
>@isbjorn.demon.co.uk:
>
>> What are the pros and cons of each

>
>UV filters help remove the haze in the sky, helps with landscape
>photography. Personally I never noticed any increase in picture quality -
>probably due to the fact my camera already has a multi-coating on the
>lens. Most people use UV filters as a cheap lens protector.
>
>Polarizers are used to filter out certain wavelengths of lights, thus
>Polarizers have the ability to reduce glare and increase the saturation
>of blues and greens. A polarizer is great if you want to get a vivid blue
>sky or lush greens you see in photographs in magazines or posters. A
>polarizer can also be used to shoot photographs through glass or water by
>reducing reflection.
>
>In short, a UV filter is useful as a lens protector, a Polarizer makes
>your pictures pretty for landscape photography (because there are a lot
>of blues/greens in nature).


A polarizer has a light loss of almost 2 stops, whereas a UV filter has
essentially no light loss.

--
Best regards,
John Navas
[PLEASE NOTE: Ads belong *only* in rec.photo.marketplace.digital, as per
<http://bobatkins.photo.net/info/charter.htm> <http://rpdfaq.50megs.com/>]
 
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GLC1173
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      02-22-2004
Andrew wrote:
>Been recommended both UV filter and >Polarising filter, both as
>alternatives for a semi-permanent >attachment when outdoors.
>What are the pros and cons of each, and >overall which would be the
>better choice?


If it's just to protect the front lens, get the UV filter. It won't alter
the photo - but the polarizing filter sure would.
~~~~~~~~~~~~~~~~~~~~~
<B>Dissident news - plus immigration, gun rights, nationwide weather
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official newspaper of the Vast Right Wing Conspiracy</A></b></i>

 
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Jeffrey
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      02-22-2004

"Lucas Tam" <(E-Mail Removed)> wrote in message
news:Xns949789969473nntprogerscom@140.99.99.130...
....
> Polarizers are used to filter out certain wavelengths of lights, thus
> Polarizers have the ability to reduce glare and increase the saturation
> of blues and greens. ...


My understanding is that, Polorisers only allows light to go through the
filter that has a certain polarity (depending upon the orientation of the
filter), so it is good for removing glare (that light apparenly has waves
with all different polarities). I did not understand that they also
filtered out certain wavelenghts, but you are corect that they do increase
the saturations of blues and greens (but I do not quite understand why).

Jeffrey


 
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AArDvarK
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      02-22-2004

A polarizer I recommend not, for the same reasons mentioned
previously in this thread ... and I think a UV would do nothing
other than protect the front element, UV factor possibly being
useless for a digital ccd ... my favorite idea is a 'sky 1A' which
will do two jobs, cancel out atmospheric blue hues on distant
objects such as mountains as well as protect, some examples:
http://www.pbase.com/image/26181857
http://www.pbase.com/image/25833021
http://www.pbase.com/image/25288161
http://www.pbase.com/image/25288050
http://www.pbase.com/image/26082645

Alex

"Andrew Brydon" <(E-Mail Removed)> wrote in message news:m$(E-Mail Removed)...
>
> Been recommended both UV filter and Polarising filter, both as
> alternatives for a semi-permanent attachment when outdoors.
> What are the pros and cons of each, and overall which would be the
> better choice? [Local shop only has circular polarisers, if it matters.]
> --
> Andrew Brydon
> Life is just the beta-version of death



 
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Lucas Tam
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      02-22-2004
"Jeffrey" <(E-Mail Removed)> wrote in
news:4038601e$0$5870$(E-Mail Removed) :

>
> "Lucas Tam" <(E-Mail Removed)> wrote in message
> news:Xns949789969473nntprogerscom@140.99.99.130...
> ...
>> Polarizers are used to filter out certain wavelengths of lights, thus
>> Polarizers have the ability to reduce glare and increase the
>> saturation of blues and greens. ...

>
> My understanding is that, Polorisers only allows light to go through
> the filter that has a certain polarity (depending upon the orientation
> of the filter), so it is good for removing glare



You're probably more correct in saying the polarizer filters out certain
refractions of light. I made the post quite late and couldn't think of
the right word.

Found this article online:

http://www.mindspring.com/~dmerriman/Polawrk.htm

I'm not sure how accurate it is, but seems to explain how polarizers
work.


--
Lucas Tam ((E-Mail Removed))
Please delete "REMOVE" from the e-mail address when replying.
http://members.ebay.com/aboutme/coolspot18/
 
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Joseph Meehan
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      02-22-2004
Andrew Brydon wrote:
> Been recommended both UV filter and Polarising filter, both as
> alternatives for a semi-permanent attachment when outdoors.
> What are the pros and cons of each, and overall which would be the
> better choice? [Local shop only has circular polarisers, if it
> matters.]


Polarizing filters should NOT be used on a regular bases. They make
changes to the recorded image that you may or may not like. They also
reduce the total amount of light reaching the sensor by a significant
amount. They are the filter I would consider the most useful to the digital
photographer as you can't reproduce the effect after the exposure, but you
don't want them all the time. Circular polarizers are required for some
cameras to assure the automatic systems work properly.

UV filters filter out UV and, depending on the filter, some visible
light in the blue range. Based on what I have been told and from my own
quick experiments, digital cameras by nature have very little if any
sensitivity to UV light.

Most people who own UV filters have little or no idea what they really
do. They use them not for their filtering effect, but because the want to
"protect" the lens.

In the real world, very little reduction in image quality will be caused
by the additional glass. UV filters are easier to find and cheaper than
plain glass.

Also in the real world there is very little to fear from meaningful
accidental damage to a lens under normal situations. A small scratch or
nick on a lens really does almost nothing to the capabilities of the lens.
While there may be some loss of resale value due to a scratch, with
digitals, even a two year old camera is so far out of date that resale value
is not a real issue. SLR's with interchangeable cameras are an exception

I would have to say that much more is paid for UV filters every year,
than value lost by scratches etc.

In short, if it makes you feel good to use one, do it and don't feel
bad, if it makes you feel good not to use one, then don't and don't worry.

Personally I don't wear suspenders and a belt, I often don't even wear
either.



--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math



 
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Aaron Queenan
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      02-22-2004
"Jeffrey" <(E-Mail Removed)> wrote in message
news:4038601e$0$5870$(E-Mail Removed) ...
>
> "Lucas Tam" <(E-Mail Removed)> wrote in message
> news:Xns949789969473nntprogerscom@140.99.99.130...
> ...
> > Polarizers are used to filter out certain wavelengths of lights, thus
> > Polarizers have the ability to reduce glare and increase the saturation
> > of blues and greens. ...

>
> My understanding is that, Polorisers only allows light to go through the
> filter that has a certain polarity (depending upon the orientation of the
> filter), so it is good for removing glare (that light apparenly has waves
> with all different polarities). I did not understand that they also
> filtered out certain wavelenghts, but you are corect that they do increase
> the saturations of blues and greens (but I do not quite understand why).


They shouldn't filter out any colours, unless you are using a really cheap
filter. What you are seeing is that the sky 90 degrees from the sun
position is mostly polarised light, and the light reflecting off leaves and
water is polarised. Hence the polariser affects the colours and makes them
stand out or subdue, depending upon the angle of the polarised light
compared to the polariser.

Regards,
Aaron Queenan.


 
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JPS@no.komm
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      02-23-2004
In message <4038601e$0$5870$(E-Mail Removed)>,
"Jeffrey" <(E-Mail Removed)> wrote:

>I did not understand that they also
>filtered out certain wavelenghts,


If you understood that, you would understand wrong.

They may be frequency-selective outside the visible light spectrum, but
within it, they are pretty neutral.

>but you are corect that they do increase
>the saturations of blues and greens (but I do not quite understand why).


That's only because green leaves, sky, and water are the most likely
things to have glare. The glare color is dependent mainly on the color
of the light source, so if you have a highly saturated bject, and it has
white glare on it, it will reduce the contrast of the detail, and the
saturation. A polarizer helps see the object itself, underneath the
glare.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <(E-Mail Removed)>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

 
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