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Circular polarizing filter and overexposure issues
I recently purchased a circular polarizing filter in the hope that it would make the clouds "pop" in my landscape photos and help me avoid getting overexposed skies. After my first few times taking photos using the filter I must say that I'm not impressed either my filter isn't very good, or I don't know what I'm doing and I'm not using it as I should be..

For example, here's a photo which I took recently and the sky is almost totally washed out (no post processing other than image size reduction): http://www.flickr.com/photos/monocongo/2657224053/.

With Photoshop I was able to get a reasonable looking image from the photo after boosting the highlights by almost 100%, but still the sky looks to be overexposed in my opinion: http://www.flickr.com/photos/buddhafinger/2657109447/.

Can anyone comment on what I might be doing wrong? Maybe I'm not rotating the filter to the right position? This is difficult because I don't see very much difference at all when I rotate the filter, so it's hard to know when I'm getting more or less polarization modification from the filter. Is it possible that the filter I'm using (Quantaray Professional Digital CPL) is of poor quality, and I need to step up to a better filter? Can I expect to have a reasonable looking image straight from the camera, and if so what's the trick to getting a correctly exposed sky without underexposing the rest of the shot, or can I always expect to have to pull out highlights to see the cloud details? Or am I simply expecting too much detail from a single exposure, and I should try to get better images using HDR techniques or bracketing?.

Thanks in advance for your comments and/or suggestions..

James.

Http://www.flickr.com/photos/buddhafinger/..

Comments (16)

James,.

Firstly, the magnitude of the effect depends on where the sun is with respect to you, so the effect can be strong or weak depending on which bit of the sky you are pointing the camera at. The best effect is obtained with the sun side-on (90 degree) to you: if it is directly behind you the effect will be much less. See.

Http://www.offrench.net/photos/articles/polarizing_filter.php.

Secondly, it sounds as though you may not be rotating the front of the filter to the best angle to get the optimal effect. I found it quite obvious when the effect is at it's strongest as blue sky gets much darker. This may be related to the point above, that you are taking a picture in an orientation where the effect is not strong anyway: the bright (pverexposed) but of cloud looks as though the sun is right behind it, in which case you were shooting at an angle which would give the weakest effect..

The fact that the clods are overexposed is a separate issue and suggests that your meter reading is biased towards the ground which looks quite shady and dark..

Best wishes.

Mike..

Comment #1

There should be an arrow or dot somewhere on the polarizer. Make sure that symbol is rotated toward the sun..

Here's a good article on how to use a polarizer..

Http://www.popphoto.com/pdfs/2002/0902/Polarizer.pdf..

Comment #2

James Adams wrote:.

I must say that I'm not impressed either myfilter isn't very good, or I don't know what I'm doing and I'm notusing it as I should be..

May very well be the second option as a c.pol isn't the panacea some think it is.

For example, here's a photo which I took recently and the sky isalmost totally washed out (no post processing other than image sizereduction): http://www.flickr.com/photos/monocongo/2657224053/.

I can't access flickr from work, so I can't see the image, but that sounds like overexposure to me. A polarizer won't keep you from overexposing. It can help cut glare but if you really stuff the exposure, it won't make a bit of difference. What metering mode/method were you using at the time?.

Can anyone comment on what I might be doing wrong? Maybe I'm notrotating the filter to the right position? This is difficult becauseI don't see very much difference at all when I rotate the filter, soit's hard to know when I'm getting more or less polarizationmodification from the filter..

This could be related to when you are using it. A c.pol works best when the sun's rays are striking the subject at about 90 degrees from the camera angle. If the light is right you should see a difference..

Is it possible that the filter I'musing (Quantaray Professional Digital CPL) is of poor quality, and Ineed to step up to a better filter?.

Could be. Quantaray isn't exactly regarded as high quality anything. A good filter (of any sort) is going to be more expensive. My B+W c.pol (77mm) set me back close to $150. And worth every penny of it..

Can I expect to have areasonable looking image straight from the camera, and if so what'sthe trick to getting a correctly exposed sky without underexposingthe rest of the shot,.

The dynamic range of pretty much any daylight scene with both sky and ground will exceed the ability of pretty much all modern cameras. (And film.) So there is a trade off. Do you want the details in the sky (which will leave the ground too dark) or do you want the details on the ground (which will overexpose the sky)?.

In order to get it all in one shot, what you would need are graduated split ND filters. Those would darken the sky (like sunglasses) but leave the ground as is. The trouble with those is that you really need a flat horizon. Hills and trees are rarely flat enough to avoid being partially covered by the ND portion of the filter..

Another way is to bracket the shots (preferably using a tripod) and combine them in post. Not necessarily via HDR, but just carefully masking the sky (or surface) from one frame into the other..

Or can I always expect to have to pull outhighlights to see the cloud details? Or am I simply expecting toomuch detail from a single exposure, and I should try to get betterimages using HDR techniques or bracketing?.

See above. (Sorry. Didn't read far enough ahead.).

Chefziggyhttp://www.pbase.com/chefziggy/lecream..

Comment #3

It worked as advertised. You seem to have unrealistic expectations..

Http://www.great-landscape-photography.com/polarizing-filter.html.

And as far as balancing sky detail with foreground... a circ. pol. will decrease light transmitted over the entire image. To hold back the sky while properly exposing foreground, you want to use a split or graduated neutral density filter..

James Adams wrote:.

I recently purchased a circular polarizing filter in the hope that itwould make the clouds "pop" in my landscape photos and help me avoidgetting overexposed skies. After my first few times taking photosusing the filter I must say that I'm not impressed either myfilter isn't very good, or I don't know what I'm doing and I'm notusing it as I should be..

For example, here's a photo which I took recently and the sky isalmost totally washed out (no post processing other than image sizereduction): http://www.flickr.com/photos/monocongo/2657224053/.

With Photoshop I was able to get a reasonable looking image from thephoto after boosting the highlights by almost 100%, but still the skylooks to be overexposed in my opinion:http://www.flickr.com/photos/buddhafinger/2657109447/.

Can anyone comment on what I might be doing wrong? Maybe I'm notrotating the filter to the right position? This is difficult becauseI don't see very much difference at all when I rotate the filter, soit's hard to know when I'm getting more or less polarizationmodification from the filter. Is it possible that the filter I'musing (Quantaray Professional Digital CPL) is of poor quality, and Ineed to step up to a better filter? Can I expect to have areasonable looking image straight from the camera, and if so what'sthe trick to getting a correctly exposed sky without underexposingthe rest of the shot, or can I always expect to have to pull outhighlights to see the cloud details? Or am I simply expecting toomuch detail from a single exposure, and I should try to get betterimages using HDR techniques or bracketing?.

Thanks in advance for your comments and/or suggestions..

James.

Http://www.flickr.com/photos/buddhafinger/.

Galleries: http://www.dheller.net.

I am one of the few who decry elitism...

Comment #4

No filter will make up for good light. For landscapes such as your example try early morning or late afternoon. If the sun is over your shoulder the light will have less difference between the brightest and darkest areas. I think you'll have better results this way. Side light on a subject will enhance detail. Backlight is trickier.

Especially if you're a newbie gain confidence and success by shooting early morning or late afternoon, then progress to other lighting situations..

If you're going to shoot subjects in midday try to put the subject and background in the shade or use fill flash if possible..

Composition and quality of light matter...

Comment #5

All great advice..

Although it does depend on the position of the sun in your shot (pre-processing) it would look like you did not rotate the polariser correctly. The reason you can tell is that there are very clear reflections of the clouds in the water. The effect of the polariser would be to minimise or possibly even eliminate them.

The effect should look something like the photo I posted in this thread, running concurrently here ;.

Http://forums.dpreview.com/...ums/readflat.asp?forum=1002&thread=28602792..

Comment #6

All great advice..

Indeed, thanks again to everyone who has shared their insight..

Although it does depend on the position of the sun in your shot(pre-processing) it would look like you did not rotate the polarisercorrectly. The reason you can tell is that there are very clearreflections of the clouds in the water. The effect of the polariserwould be to minimise or possibly even eliminate them.

Actually I wanted to get the sky reflected on the lake, but I was also hoping to get more detail from the clouds and not have them overexposed. As David said in a previous reply to the original posting I probably have had unrealistic expectations, as a CPL filter isn't the silver bullet I was thinking it'd be. Maybe a graduated filter would have helped me in this shot?.

Jameshttp://www.flickr.com/photos/buddhafinger/..

Comment #7

Actually I wanted to get the sky reflected on the lake, but I wasalso hoping to get more detail from the clouds and not have themoverexposed. As David said in a previous reply to the originalposting I probably have had unrealistic expectations, as a CPL filterisn't the silver bullet I was thinking it'd be. Maybe a graduatedfilter would have helped me in this shot?.

Yep..

But in either case, you need to know how polarizers work, and about glare. Mostly that polarizers are most effective 90 degrees from the sun, and virtually not effective at 0 and 180 degrees from the sun..

Next time you're out on a sunny day. Look around 360 degrees. You will see that part of the landscape is nice and saturated, and part is dull, hazy and washed out. You will also notice that the most saturated part is 180 degrees from the most washed out. Shooting into the saturated area where everything is in the light it is virtually impossible to blow out the sky. Shoot into the washed out landscape and it's almost impossible not to blow out the sky (without filters or exposure compromises).



The most important thing to do when shooting landscape is to know your subject and know when it gets it's best light. Plan your outings around that..

One final thing - ditch the quantary and get a good polarizer...

Comment #8

I though you may say that .

A graduated filter would reduced the number of stops between the correct exposure for land and sky, and therefore would stop the sky being blown out (or at least help a bit), but I think you would not get the effect of the 'clouds popping out the sky' without using a polariser. You can of course stack filters, but image quality is affected..

As the above post says though, time of day is crucial to make the best of a shot and get the best out of a polariser..

Comment #9

James Adams wrote:.

Actually I wanted to get the sky reflected on the lake, but I wasalso hoping to get more detail from the clouds and not have themoverexposed..

You should not have overexposed the sky then. A polarizor does not give you any ability to have the camera capture a wider dynamic range. While it does darken the sky for exposure, it also darkens the rest of the image..

Maybe a graduatedfilter would have helped me in this shot?.

Yes. Personally I take two exposures for blending when there is too many stops of light for the camera to capture properly in one photo. I'm not sure about stacking these two types of filters but I just find that a set of grad filters is too expensive, require lots of futzing around and can only be used where there is a fairly straight horizon line..

An underexposed sky with clouds can look really dramatic, proably what you had in mind with the polarizor but it does underexpose the rest of the scene too, so with or without the polarizor, you will often need to brighten the dark areas in post processing or use a grad filter or blend exposures if you underexpose the sky to make the clouds pop...

Comment #10

Wmsson wrote:.

You should not have overexposed the sky then. A polarizor does notgive you any ability to have the camera capture a wider dynamicrange. While it does darken the sky for exposure, it also darkens therest of the image..

... but not to the same extent. A CP filer is not just a neutral density filter which affects all parts of the picture equally. It selectively cuts out specular reflections which contain polarised light, and leaves the non-polarised light in the shadows alone. So highlights will be darkened more than shadows, i.e. the dynamic range is reduced..

Best wishesMike..

Comment #11

Thanks again to everyone who has responded and helped me learn a bit more on this topic..

Wmsson wrote:.

James Adams wrote:.

Actually I wanted to get the sky reflected on the lake, but I wasalso hoping to get more detail from the clouds and not have themoverexposed..

You should not have overexposed the sky then. A polarizor does notgive you any ability to have the camera capture a wider dynamicrange. While it does darken the sky for exposure, it also darkens therest of the image..

Maybe a graduatedfilter would have helped me in this shot?.

Yes. Personally I take two exposures for blending when there is toomany stops of light for the camera to capture properly in one photo....An underexposed sky with clouds can look really dramatic, proablywhat you had in mind with the polarizor but it does underexpose therest of the scene too, so with or without the polarizor, you willoften need to brighten the dark areas in post processing or use agrad filter or blend exposures if you underexpose the sky to make theclouds pop..

Yes I'm thinking that I need to learn to use bracketing in order to blend multiple exposures together to capture a broader dynamic range. Unfortunately it requires using a tripod, which I don't like to lug around on my hikes, but it looks like that'll probably be one of the costs of improving my landscape photos....

Jameshttp://www.flickr.com/photos/buddhafinger/..

Comment #12

IMac, therefore iAm wrote:.

Actually I wanted to get the sky reflected on the lake, but I wasalso hoping to get more detail from the clouds and not have themoverexposed. As David said in a previous reply to the originalposting I probably have had unrealistic expectations, as a CPL filterisn't the silver bullet I was thinking it'd be. Maybe a graduatedfilter would have helped me in this shot?.

Yep..

But in either case, you need to know how polarizers work, and aboutglare. Mostly that polarizers are most effective 90 degrees from thesun, and virtually not effective at 0 and 180 degrees from the sun..

Next time you're out on a sunny day. Look around 360 degrees. Youwill see that part of the landscape is nice and saturated, and partis dull, hazy and washed out. You will also notice that the mostsaturated part is 180 degrees from the most washed out. Shooting intothe saturated area where everything is in the light it is virtuallyimpossible to blow out the sky. Shoot into the washed out landscapeand it's almost impossible not to blow out the sky (without filtersor exposure compromises).



The most important thing to do when shooting landscape is to knowyour subject and know when it gets it's best light. Plan your outingsaround that..

Thanks for the good advice..

One final thing - ditch the quantary and get a good polarizer..

I returned it today and instead went for a Hoya 77mm PRO1 Super HMC CPL. Hopefully it's of much higher quality it certainly was more expensive!.

Jameshttp://www.flickr.com/photos/buddhafinger/..

Comment #13

Rotate the filter to maximize the color of the sky and then take the meter reading from the sky, hold the shutter release half way, recompose and shoot.Good luck..

Comment #14

Yes I'm thinking that I need to learn to use bracketing in order toblend multiple exposures together to capture a broader dynamic range.Unfortunately it requires using a tripod, which I don't like to lugaround on my hikes, but it looks like that'll probably be one of thecosts of improving my landscape photos....

James.

A simpler method to get part of the way to this effect is to shoot in RAW and then process two different versions, one optimised for the bright parts of the picture (e.g. sky, letting the landscape be too dark) and one optimised for the dark parts (e.g. land, letting the sky be too bright). Then merge the resulting two images in Photoshop. Not as good as 'proper' HDR but you don't have to carry a tripod!.

Best wishes.

Mike..

Comment #15

What you read from previous replys were right. Almost.But nobody mention this. Look on first photo andsee clouds reflection from lake. It shouldn't be there.It is looks like no CPL at all to me.Here is my way to check CP filter. Its obvious and you know thatbut lets make sure....

Look through polarised sun glasses and CP filter then rotate last one. If you don't have glasses put over any LCD screen (watch, calculator etz.).Can you see difference?.

Even with cheap filter you can almost completely eliminate reflection from water. If I don't have money to buy good filter, still better to have cheap one and make just two photos with and without filter. Then at home make decision and PP..

Thanks...

Comment #16

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This question was taken from a support group/message board and re-posted here so others can learn from it.

 

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