LCD Screen and Polarizing Filter

In article <kf9d039gtvq1osrfa86r95oq19oqula378 RemoveThis @4ax.com>,
eddie RemoveThis @rukidding.com says...
> I recently purcahsed a Canon G7 and have since added a Canon
> Conversion Lens Adapter so that I can use filters on the camera -
> mostly Neutral Density and graduated ND filters.
>
> The camera has a view finder as well as a monitor screen but I will
> not be able to use the viewfinder to see the effects of any of the
> filters as the viewfinder will not be covered by the filter, only the
> camera lens itself.
>
> Since I live in an area that has very bright sunshine most of the
> time, I have found that using a polarizing filter is almost a must and
> was planning on purchasing a circular one to use on this camera set
> up. But before I part with the $50 - $60 on the polarizer...
>
> My question is, will I be able to easily see the effects of the
> polarizer on the cameras monitor screen, enough so that I can use the
> filter effectively?

1. Half-press the shutter to lock exposure

2. Rotate the polariser filter

3. The LCD will now show the effects of the polariser filter.

You must lock the exposure (either by half-pressing the shutter or going
into manual mode) otherwise the camera adjusts all the time the exposure
you see nothing.
--

Alfred Molon
------------------------------
Olympus 50X0, 7070, 8080, E300, E330, E400 and E500 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: LCD Screen and Polarizing Filter 

On Sun, 25 Mar 2007 23:27:47 +0200, Alfred Molon
<alfred_molonCANCEL.RemoveThis@yahoo.com> wrote:

>In article <kf9d039gtvq1osrfa86r95oq19oqula378.RemoveThis@4ax.com>,
>eddie@rukidding.com says...
>> I recently purcahsed a Canon G7 and have since added a Canon
>> Conversion Lens Adapter so that I can use filters on the camera -
>> mostly Neutral Density and graduated ND filters.
>>
>> The camera has a view finder as well as a monitor screen but I will
>> not be able to use the viewfinder to see the effects of any of the
>> filters as the viewfinder will not be covered by the filter, only the
>> camera lens itself.
>>
>> Since I live in an area that has very bright sunshine most of the
>> time, I have found that using a polarizing filter is almost a must and
>> was planning on purchasing a circular one to use on this camera set
>> up. But before I part with the $50 - $60 on the polarizer...
>>
>> My question is, will I be able to easily see the effects of the
>> polarizer on the cameras monitor screen, enough so that I can use the
>> filter effectively?
>
>1. Half-press the shutter to lock exposure
>
>2. Rotate the polariser filter
>
>3. The LCD will now show the effects of the polariser filter.
>
>You must lock the exposure (either by half-pressing the shutter or going
>into manual mode) otherwise the camera adjusts all the time the exposure
>you see nothing.

Are you sure?
It seems the polarizer doesn't just change the overall light, it
changes the light in some parts of the image.
This should be see visible in the LCD without pressing the shutter
button.
Your eyes constantly adjust, but the effects of polarizing sunglasses
are easily visible.
And, the effects of polarizers are easily visible in (D)SLR
viewfinders, without first half-pressing the shutter button.

--
Bill Clinton raised four hundred
thousand dollars for Hillary's
campaign at a private home in
Cincinnati last week. He's helped
her raise two hundred million
dollars for two Senate races and
one presidential campaign.
At what point is he even?
 >> Stay informed about: LCD Screen and Polarizing Filter 

Your post is a bit confusing. You say that you live in an area of very
bright sunshine and therefore a polarizing filter is a must. However,
if all you are dealing with is an overbright scene, a neutral density
filter is what you need. You don't need to see its effect, because it
simply decreases the brightness of the scene, and your camera ajusts its
exposure accordingly.

A polaroid filter will also cut down the light, but it can significantly
affect the appearance of the scene. It interacts with polarized light,
and depending how it is set, it can dramatically decrease the intensity
of some polarized light. Now maybe that is what you are after. On my old
Coolpix 950, I couldn't see the LCD screen in bright sunlight, so I had
no way to judge what the polaroid filter was doing as I rotated it. To
make things simple, I used polaroid sunglasses and determined how the
camera filter and the sunglasses line up with one another for
polarization effect; camera polaroid filters always have a mark
indicating the plane of polarization. I would simply tilt my head from
side to side until I liked the look of the scene I was shooting, note
the angle of my head for the view I liked best, and set the filter the
same way. It's actually quite easy and fast to do.

Joe



eddie rukidding wrote:
> I recently purcahsed a Canon G7 and have since added a Canon
> Conversion Lens Adapter so that I can use filters on the camera -
> mostly Neutral Density and graduated ND filters.
>
> The camera has a view finder as well as a monitor screen but I will
> not be able to use the viewfinder to see the effects of any of the
> filters as the viewfinder will not be covered by the filter, only the
> camera lens itself.
>
> Since I live in an area that has very bright sunshine most of the
> time, I have found that using a polarizing filter is almost a must and
> was planning on purchasing a circular one to use on this camera set
> up. But before I part with the $50 - $60 on the polarizer...
>
> My question is, will I be able to easily see the effects of the
> polarizer on the cameras monitor screen, enough so that I can use the
> filter effectively?
>
> Any thoughts or shared experiences appreciated!
>
>
>
 >> Stay informed about: LCD Screen and Polarizing Filter 

In article <o1sf03l2l6q293q6lcpg54d7djabelr7ee RemoveThis @4ax.com>,
BigBill RemoveThis @there.com says...

> >You must lock the exposure (either by half-pressing the shutter or going
> >into manual mode) otherwise the camera adjusts all the time the exposure
> >you see nothing.
>
> Are you sure?
> It seems the polarizer doesn't just change the overall light, it
> changes the light in some parts of the image.
> This should be see visible in the LCD without pressing the shutter
> button.
> Your eyes constantly adjust, but the effects of polarizing sunglasses
> are easily visible.
> And, the effects of polarizers are easily visible in (D)SLR
> viewfinders, without first half-pressing the shutter button.

Yes, I'm sure, but feel free to ignore my advice.
--

Alfred Molon
------------------------------
Olympus 50X0, 7070, 8080, E300, E330, E400 and E500 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: LCD Screen and Polarizing Filter 

Alfred Molon wrote:
> In article <7ori03hvnd2evm3uifg5242ieern9qc800 DeleteThis @4ax.com>,
> BigBill DeleteThis @there.com says...
>
>>>>>You must lock the exposure (either by half-pressing the shutter or going
>>>>>into manual mode) otherwise the camera adjusts all the time the exposure
>>>>>you see nothing.
>>>>
>>>>Are you sure?
>>>>It seems the polarizer doesn't just change the overall light, it
>>>>changes the light in some parts of the image.
>>>>This should be see visible in the LCD without pressing the shutter
>>>>button.
>>>>Your eyes constantly adjust, but the effects of polarizing sunglasses
>>>>are easily visible.
>>>>And, the effects of polarizers are easily visible in (D)SLR
>>>>viewfinders, without first half-pressing the shutter button.
>>>
>>>Yes, I'm sure, but feel free to ignore my advice.
>>
>>Since I use a polarizer on my 30D, and I can see the effects it causes
>>in the viewfinder without having to half-press, I will.
>
>
> Sigh. The 30D has no live preview... even if you wanted you could not
> see the effect in the LCD screen. The OP has a camera with live preview
> (G7) and for that camera you have to lock the exposure to be able to see
> the effect of the polariser filter.

I have used a polarizer on my old Dimage 7Hi and on my now current
Dimage A200 and Pentax ist-DS.
On all three cameras it is quite obvious that reflections can be cut
significantly and parts of the sky could be darkened, without stopping
the lens down (ist-DS), also by looking at the LCD on the back or
through the eye-level EVF (on both the Dimage 7Hi and A200).
There is no need to "lock exposure" to see the effect, as it is caused
by the polarizer and not by any action of the lens aperture or exposure
system in the camera.
I realy don't know what sort of camera or polarizer Mr Molon has used,
but they don't seem to act in the way experienced by other posters in
this message thread.
 >> Stay informed about: LCD Screen and Polarizing Filter 

In article <7ori03hvnd2evm3uifg5242ieern9qc800.DeleteThis@4ax.com>,
BigBill.DeleteThis@there.com says...
> >> >You must lock the exposure (either by half-pressing the shutter or going
> >> >into manual mode) otherwise the camera adjusts all the time the exposure
> >> >you see nothing.
> >>
> >> Are you sure?
> >> It seems the polarizer doesn't just change the overall light, it
> >> changes the light in some parts of the image.
> >> This should be see visible in the LCD without pressing the shutter
> >> button.
> >> Your eyes constantly adjust, but the effects of polarizing sunglasses
> >> are easily visible.
> >> And, the effects of polarizers are easily visible in (D)SLR
> >> viewfinders, without first half-pressing the shutter button.
> >
> >Yes, I'm sure, but feel free to ignore my advice.
>
> Since I use a polarizer on my 30D, and I can see the effects it causes
> in the viewfinder without having to half-press, I will.

Sigh. The 30D has no live preview... even if you wanted you could not
see the effect in the LCD screen. The OP has a camera with live preview
(G7) and for that camera you have to lock the exposure to be able to see
the effect of the polariser filter.
--

Alfred Molon
------------------------------
Olympus 50X0, 7070, 8080, E300, E330, E400 and E500 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: LCD Screen and Polarizing Filter 

On Tue, 27 Mar 2007 23:30:53 +0200, Alfred Molon
<alfred_molonCANCEL RemoveThis @yahoo.com> wrote:

>In article <7ori03hvnd2evm3uifg5242ieern9qc800 RemoveThis @4ax.com>,
>BigBill@there.com says...
>> >> >You must lock the exposure (either by half-pressing the shutter or going
>> >> >into manual mode) otherwise the camera adjusts all the time the exposure
>> >> >you see nothing.
>> >>
>> >> Are you sure?
>> >> It seems the polarizer doesn't just change the overall light, it
>> >> changes the light in some parts of the image.
>> >> This should be see visible in the LCD without pressing the shutter
>> >> button.
>> >> Your eyes constantly adjust, but the effects of polarizing sunglasses
>> >> are easily visible.
>> >> And, the effects of polarizers are easily visible in (D)SLR
>> >> viewfinders, without first half-pressing the shutter button.
>> >
>> >Yes, I'm sure, but feel free to ignore my advice.
>>
>> Since I use a polarizer on my 30D, and I can see the effects it causes
>> in the viewfinder without having to half-press, I will.
>
>Sigh. The 30D has no live preview... even if you wanted you could not
>see the effect in the LCD screen.

It has a viewfinder.
Are you trying to say that he viewfinder is innacurate when showing
the effects of a polarizer?
>The OP has a camera with live preview
>(G7) and for that camera you have to lock the exposure to be able to see
>the effect of the polariser filter.

No, unless you are talking about the overall loss of light; the
*polarizing* effects can be seen without stopping down.
Try it.

--
Charlie Sheen told a radio
interviewer Friday that the
Twin Towers were imploded by
the U.S. government. His
family is proud of his progress.
Every minute he's in a radio
station accusing his own government
of mass murder is another minute
he's not gambling online.
 >> Stay informed about: LCD Screen and Polarizing Filter 

In article <4609ba47$0$7445$5a62ac22@per-qv1-newsreader-
01.iinet.net.au>, dj_nme.TakeThisOut@hotmail.com says...

> I have used a polarizer on my old Dimage 7Hi and on my now current
> Dimage A200 and Pentax ist-DS.
> On all three cameras it is quite obvious that reflections can be cut
> significantly and parts of the sky could be darkened, without stopping
> the lens down (ist-DS), also by looking at the LCD on the back or
> through the eye-level EVF (on both the Dimage 7Hi and A200).
> There is no need to "lock exposure" to see the effect, as it is caused
> by the polarizer and not by any action of the lens aperture or exposure
> system in the camera.
> I realy don't know what sort of camera or polarizer Mr Molon has used,
> but they don't seem to act in the way experienced by other posters in
> this message thread.

As I already wrote, feel free to ignore my advice and continue using
polariser filters as you always have. Personally I do not care how you
use polariser filters. I can only tell you that in another forum people
were very happy to hear my advice because it solved their problem.

While you can see reflections go away without locking the exposure, the
fact is that most of the time people use a polariser filter to get a
deep blue sky and increase saturation/contrast.

When you frame an outdoor scene with sky in it (blue sky because a
polariser filter has virtually no effect if the sky is overcast) and
rotate the polariser filter without locking the exposure the camera will
change the exposure, because the overall brightness level in the scene
changes and digital cameras usually automatically adjust the exposure.

To check this, point your camera with polariser filter to an outdoor
scene with blue sky and see what exposure parameters the camera chooses
with the polariser filter in different angular positions.

Personally I try to maximise contrast/saturation and for this purpose I
look for the polariser angle where this is the case. If I do not lock
the exposure (either by half-pressing the shutter or going into manual
mode), the camera will modify the exposure while I turn the polariser
filter and the sky will have more or less the same brightness level. In
that case it will be impossible to find the ideal polariser angle.

I have observed this with several Olympus cameras (C1400, C2000, C5050,
C8080) and with the Sony R1, but it should be the case with all cameras,
because all digital cameras automatically adjust the exposure.

In any case, let me repeat it once again, feel free to ignore my advice.
--

Alfred Molon
------------------------------
Olympus 50X0, 7070, 8080, E300, E330, E400 and E500 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: LCD Screen and Polarizing Filter 

Alfred Molon wrote:

> In article <4609ba47$0$7445$5a62ac22@per-qv1-newsreader-
> 01.iinet.net.au>, dj_nme RemoveThis @hotmail.com says...
>
>
>>I have used a polarizer on my old Dimage 7Hi and on my now current
>>Dimage A200 and Pentax ist-DS.
>>On all three cameras it is quite obvious that reflections can be cut
>>significantly and parts of the sky could be darkened, without stopping
>>the lens down (ist-DS), also by looking at the LCD on the back or
>>through the eye-level EVF (on both the Dimage 7Hi and A200).
>>There is no need to "lock exposure" to see the effect, as it is caused
>>by the polarizer and not by any action of the lens aperture or exposure
>>system in the camera.
>>I realy don't know what sort of camera or polarizer Mr Molon has used,
>>but they don't seem to act in the way experienced by other posters in
>>this message thread.
>
>
> As I already wrote, feel free to ignore my advice and continue using
> polariser filters as you always have. Personally I do not care how you
> use polariser filters. I can only tell you that in another forum people
> were very happy to hear my advice because it solved their problem.
>
> While you can see reflections go away without locking the exposure, the
> fact is that most of the time people use a polariser filter to get a
> deep blue sky and increase saturation/contrast.

Increased saturarion in the blue of the sky, but _lower_ contrast
between the sky and ground so that the sky doesn't blow out to bright
white while exposing for a (more often than not, darker) subject on the
ground.

> When you frame an outdoor scene with sky in it (blue sky because a
> polariser filter has virtually no effect if the sky is overcast) and
> rotate the polariser filter without locking the exposure the camera will
> change the exposure, because the overall brightness level in the scene
> changes and digital cameras usually automatically adjust the exposure.

The camera will meter with the sky slighty darkened, which is the whole
point.
It will be abundantly clear also without locking exposure that when
using a polariser and a wide-angle lenses that part of the sky will
darker and parts will be lighter, or by pointing your camera (with a
longer or zoomed in slightly lens) at a different part of the sky.

> To check this, point your camera with polariser filter to an outdoor
> scene with blue sky and see what exposure parameters the camera chooses
> with the polariser filter in different angular positions.

The obvious difference (assuming that the part of the sky in the image
is oriented roughly 90 degrees from the direction of the Sun) will be
that everything else except the sky will appear to be brighter, which is
the desired effect and not contingent on "locking exposure" first.

> Personally I try to maximise contrast/saturation and for this purpose I
> look for the polariser angle where this is the case. If I do not lock
> the exposure (either by half-pressing the shutter or going into manual
> mode), the camera will modify the exposure while I turn the polariser
> filter and the sky will have more or less the same brightness level. In
> that case it will be impossible to find the ideal polariser angle.

If you are only an shooting image of the sky, then why bother with a
polariser in the first place?.
Just let the camera adjust exposure to not blow-out the sky.
The whole purpose of using a polariser is to make the sky darker in
relation to a subject, so it realy doesn't matter if the camera has done
AE to compensate, because it would have made the whole scene brighter
while the relative brightness of the sky is reduced.

Unless your memory is so bad that can't remember if you attached the pol
filter in the first place...

> I have observed this with several Olympus cameras (C1400, C2000, C5050,
> C8080) and with the Sony R1, but it should be the case with all cameras,
> because all digital cameras automatically adjust the exposure.
>
> In any case, let me repeat it once again, feel free to ignore my advice.

Your advice is as bogus as ever, so there is no loss in ignoring your
advice, but I feel compelled to correct you so as to not mislead an
innocent reader that has no experience on the subject.
 >> Stay informed about: LCD Screen and Polarizing Filter 

In article <obhl03t3670680mtcdeo6u719hbqp8k2hj.DeleteThis@4ax.com>,
BigBill.DeleteThis@there.com says...

> It has a viewfinder.

What a bold statement

> Are you trying to say that he viewfinder is innacurate when showing
> the effects of a polarizer?

Of course not. I'm surprised you put this question.

> No, unless you are talking about the overall loss of light; the
> *polarizing* effects can be seen without stopping down.
> Try it.

Yes, I tried already and speak out of experience. See my other post.
--

Alfred Molon
------------------------------
Olympus 50X0, 7070, 8080, E300, E330, E400 and E500 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: LCD Screen and Polarizing Filter 

In article <460b0c68$0$7421$5a62ac22@per-qv1-newsreader-
01.iinet.net.au>, dj_nme.RemoveThis@hotmail.com says...

> Just let the camera adjust exposure to not blow-out the sky.
> The whole purpose of using a polariser is to make the sky darker in
> relation to a subject, so it realy doesn't matter if the camera has done
> AE to compensate, because it would have made the whole scene brighter
> while the relative brightness of the sky is reduced.

Not sure what we are disagreeing about, but it is possible that we are
talking past each other. Here is what I am suggesting:

1. Half press shutter to lock exposure (or go into manual mode)
2. Rotate the polariser filter until the sky is darkest in the LCD
screen
3. Unlock the exposure by releasing the shutter button or setting the
camera into automatic mode
4. Let the camera meter and then take the shot.

If the exposure is not locked in step 2, the camera will automatically
adjust the exposure and thereby the brightness level in the LCD and it
will be tough to identify the darkest sky position. Especially
considering that you are using the camera in broad daylight and it will
be difficult to see the image in the LCD.

> Your advice is as bogus as ever, so there is no loss in ignoring your
> advice, but I feel compelled to correct you so as to not mislead an
> innocent reader that has no experience on the subject.

Once again, I do not care about what you think of my advice. I can only
tell you that in another forum, people who followed my advice were very
happy, because it helped them solve the problem of how to set the
polariser filter when using an LCD for framing.

In any case, let people decide if this piece of advice is useful for
them or not. It costs nothing to try it out - just half-press the
shutter, rotate the polariser and see the effect on the LCD screen.

I might add that I've been using this technique for years with excellent
results.
--

Alfred Molon
------------------------------
Olympus 50X0, 7070, 8080, E300, E330, E400 and E500 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: LCD Screen and Polarizing Filter