Fun with Polarizers

[SNC1923]

I took a rare solo ride through the Kern River Canyon (Hwy 178) this afternoon in search of some photos. What I ended up with was an object lesson in the many benefits of using a polarizing filter. If you're not familiar with them, polarizers are adjustable, dark filters that adjust the incoming light. They work best when photographing a 90 degree angle to the sun.

First and foremost, a polarizing filter can be used to bring out the blue in the sky.

http://SNC1923.smugmug.com/photos/255653917_FSx55-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255653917&ImageKey=FSx55)

http://SNC1923.smugmug.com/photos/255654611_tYSnE-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255654611&ImageKey=tYSnE)

http://SNC1923.smugmug.com/photos/255655116_b6C9n-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255655116&ImageKey=b6C9n)

I'm pleased to note that the self-cleaning sensor on my Canon 40D seems to be working quite well.

A second benefit of a polarizing filter is its ability to saturate the image by reducing or eliminating reflections, in this case, on the water's surface.

http://SNC1923.smugmug.com/photos/255657658_nTMBY-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255657658&ImageKey=nTMBY)

Kern River taken at 17mm (28mm equivalent)

http://SNC1923.smugmug.com/photos/255656874_N34ia-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255656874&ImageKey=N34ia)

Kern River taken at 85mm (135mm equivalent)

The third benefit of a polarizing filter is that it functions also as a neutral density filter. The dark filter reduces the amount of incoming light by two f-stops. This is true of all polarizers, though specific neutral density filters can be purchased in 4, 8, or more stops of density.

Why would anyone want this? Sometimes you want to shoot something with a low shutter speed in bright daylight. You can lower the ISO to 100, and you can stop the lens down to f/32, but sometimes you need a little bit more. That's where an ND filter, or in this case, a PL filter, comes in handy.

http://SNC1923.smugmug.com/photos/255658018_s3UGe-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255658018&ImageKey=s3UGe)

1.3 secs. @ f/32

http://SNC1923.smugmug.com/photos/255658427_BcmAt-XL.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255658427&ImageKey=BcmAt)

2 secs. @ f/32

http://SNC1923.smugmug.com/photos/255656214_V52Wm-XL.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255656214&ImageKey=V52Wm)

8/10 sec. @ f/29

http://SNC1923.smugmug.com/photos/255655754_KUxZU-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=255655754&ImageKey=KUxZU)

1/2 sec. @ f/29

It should go without saying the four photos above were all taken on a sturdy tripod. A darker ND filter would have resulted in slower shutter speeds and a more "painterly" quality to the water.

Click on any image for EXIF info.

[bmwdean]

Feb. 17, 2008 -- Nikon D300 & Hoya circular polarizer.

The white 1967 R60/2 (http://jeff.dean.home.att.net/slash2.htm) in the foreground causes the exposure to darken the sky even more.

[rocketman]

Nice shots!

I discovered the G9 has an ND filter built in, reduces the f stop by a factor of 2 (I think?0 I used it a few times on my recent trip for some of the really birght daylight high noon shots. I'll have dig those out when I get a chance.


Love the water fall shots at slow speeds very nice effect.

RM

[SNC1923]

Nice shots!

I discovered the G9 has an ND filter built in, reduces the f stop by a factor of 2 (I think?0 I used it a few times on my recent trip for some of the really birght daylight high noon shots. I'll have dig those out when I get a chance.


Love the water fall shots at slow speeds very nice effect.

RM

I think it's actually a factor of 3 (3X). I haven't had a chance to use it yet, but I was sure impressed to find it there. It's mechanical too; you can hear/feel a "thunk" when you deploy it from the menu. Pretty cool. . . .

[rocketman]

I think it's actually a factor of 3 (3X). I haven't had a chance to use it yet, but I was sure impressed to find it there. It's mechanical too; you can hear/feel a "thunk" when you deploy it from the menu. Pretty cool. . . .

So you have new toy in hand, eh?:laugh

RM

Toys are good!
being able to afford them.....




priceless :laugh

[KBasa]

Anybody using one? Any thoughts on them? Use one for outdoors?

[bmwdean]

Yes.

http://www.bmwmoa.org/forum/showthread.php?t=23799

http://jeff.dean.home.att.net/photowhite.htm

[dancogan]

Yes, use it almost exclusively outdoors. I love it for green foliage on rainy or overcast days. It takes away the reflections and deepens the greens. And of course, there are times I want a more dramatic sky, or more emphasis on the clouds, so I use it then, too.

[SNC1923]

It's an indispensable accessory. Far from a bauble or a gadget, it can have a profound effect on your images. Get one for each filter size you have among your lenses.

You'd use it at the same times as you would tend to use a pair of polarized sunglasses. It works most effectively when shooting at a 90 degree angle to the sun. And it does all the things Dan outlined above. See the thread Jeff points to for a number of samples.

I'm not sure if linear polarizers are even still available, but be sure you get a "circular" polarizer as it is what will work with your autofocusing system. Get a good one (Hoya, Tiffen) but you don't need to go crazy (B+W) unless you're a frantic like me.

Nikon makes an awfully nice one. Theirs used to take a dedicated hood, too. . . .

[KBasa]

Feb. 17, 2008 -- Nikon D300 & Hoya circular polarizer.

The white 1967 R60/2 (http://jeff.dean.home.att.net/slash2.htm) in the foreground causes the exposure to darken the sky even more.


Nice photo. :thumb


Nice tankbag. :D

[bmwdean]

Nice photo. :thumb


Nice tankbag. :D

I think you have one of those too, right Dave?

[bluestune]

Outstanding Tom!

[1024JLC]

Just be careful to not over saturate your photos...

[bricciphoto]

Just be careful to not over saturate your photos...

Amen. Black skies on sunny days aren't cool. ;)

I use polarizers a lot. I use them occasionally indoors to minimize surface reflections, particularly if glassware is involved. The downside is you lose a couple stops.

Also there are a number of polarizers that incorporate other filtration such as 81 warming filters, etc. They are nice too and save the effort of using two discrete filters.

Lastly, if you purchase the more expensive polarizers/filters, you can use step down (or is it step up?) rings to use them on different size lenses as opposed to having many expensive filters waiting to get damaged/scratched in your travels.

[Paul_F]

In the last 35 years, each time that I buy a new lens, I also buy a polarizer filter for that lens. Used in the right conditions, it saturates outdoor colours, eliminates reflections and darkens skies, with both colour and black and whites images.

[bmwdean]

Amen. Black skies on sunny days aren't cool. ;)


Question: Is the sky in the photo below too "black?"

<img border=1 width=900 src=http://jeff.dean.home.att.net/weiss-left.jpg>

Personally, I like the sky's color. Of course, part of it is due to being in Arizona, where the sky is usually a deep color, and part is due to the exposure meter reading the white bike, thus darkening the sky.

[torags]

Polarizers are a necessity for mid day shooting.

But there are other occasions when they're important.

I have both the Cokin set up for linear polarizers and a few circular polarizers for each lens.

I use the cir for mid day to get blue in the sky. On one occasion both the cir and linear were appropriate. That was at the Bonneville salt flats where the ground was absolute white and full of glare & the sky was bleached.

If you want a sunset and want to keep some detail in the foreground (rather than silhouettes) then a linear polarizer will help. I have a graduated Cokin that goes as dark as 3 stops (you can adjust to 1 or 2 stop).

But make sure you don't just slap either polarizer on and expect it to work; you have to adjust it, which is easy to do.

This is the best example I have of the value of linear polarizers. I got fog detail in the foreground while reducing the super glare of the sunset to get a definitive orb

http://torags.smugmug.com/photos/189326447_NLrrj-M.jpg

[GlobalRider]

My filter is on all the time. It protects my lens and does what a polarizing filter is supposed to do.

[widebmw]

I think the most polarizing is the K&N versus stock paper argument.:scratch
:whistle :bolt

[dancogan]

Question: Is the sky in the photo below too "black?"
Personally, I like the sky's color. Of course, part of it is due to being in Arizona, where the sky is usually a deep color, and part is due to the exposure meter reading the white bike, thus darkening the sky.
Jeff, I'll take a stab at answering your question, but it's really a matter of taste more than "too black". In my opinion, the sky seems unnaturally dark, particularly in the upper left hand portion. When showing a wide expanse of sky a polarizer will often yield uneven results unless the entire sky is at roughly the same angle from the sun. I'm guessing you may have used somewhat of a wide angle lens for the shot, and the polarizer is not able to provide an even amount of polarization across that vast expanse. But maybe you already know that. By the way, I love the shot, regardless of the technical nit I'm picking!

[Gil]

This is something I have explored for years. Polarizing filters are a great tool for bringing blue skies into rich colors and not bleaching them out by over exposing. They also work great when shooting great bodies of water with glare and shine. Even sunsets. There is a bit of a science since wide angles, zoom lenses and fixed lenses, all react slightly different. You can turn the polirizer to an angle where you are pleased with the image. With a polarizer filter, you are in control. Promaster carries one that's made by Hoya, which is a Tokina company. It's a pretty darn good filter. Cokin, Tiffen, and B+W are also great. I have never had a B+W, but have heard they are the best from other collegues.

[bricciphoto]

Question: Is the sky in the photo below too "black?"

<img border=1 width=900 src=http://jeff.dean.home.att.net/weiss-left.jpg>

Personally, I like the sky's color. Of course, part of it is due to being in Arizona, where the sky is usually a deep color, and part is due to the exposure meter reading the white bike, thus darkening the sky.

Hey Jeff, Because you're quoting me, let me add my two cents. :p Yes, the sky appears unnaturally dark, but a polarizer can turn a blue sky almost black. Your sky isn't quite there yet. I can't tell if you cropped your shot or not, but the sky isn't equally dark on each side, which could be due to the polarizer not being rotated to balance the corners, or from cropping. The R60/2 is perfectly exposed and unfortunately that forced your sky to go a bit dark. A graduated neutral density filter across the bottom of the frame would have yielded a more natural looking and better balanced exposure in my opinion, but It's a great shot and I love the color of the bike against the blue sky. It really is an excellent demonstration of the utility of a polarizer, minus my two minor criticisms--recognizing it's a difficult task to manage that much contrast in a single exposure. :wave


I'm sure if I looked I could find an example of a black sky somewhere in the great expanse of the Internet. They're usually shown in the photo mags in "what not to do" scenarios, too.

[bricciphoto]

Just adding some additional thoughts on the discussion above. The black sky effect is particularly acute with super saturated high contrast transparency film coupled with extreme wide angle lenses (<20 mm). Super wide lenses also bring a whole host of issues regarding filter size, vignetting, etc. into play. I'm thinking of Fuji Velvia 50 specifically. I have no idea how the various digital sensors stack up against transparency film in terms of saturation and contrast. I'll see if I can find an example of what I'm talking about. I've probably shot a few over the years, but it's doubtful I kept the transparency (for obvious reasons :p ).

This isn't Velvia, it's a Canon 1Ds sensor, but it is a high contrast scene using a polarizer. I used this shot as an example of what happens to snow and skies with a polarizer in my photo class. You can see it's difficult to expose the sky, snow and highlight (edge of drift) correctly in one exposure. Had this been shot with Velvia, the sky would have been almost black. You can see the sky isn't really blue at all. The snow isn't purely white because it's reflecting the blue sky. Hope this helps.

http://bricciphoto.smugmug.com/photos/256790076_Du999-L.jpg

[SNC1923]

Ben,

If you don't mind, I'll give it a shot. I have a few photos that I think are examples of what you are talking about.

These are all shot with a 40D and a 10-22mm zoom. At the wide end, that's a 16mm equivalent (IOW very wide-angle). All shot with a B+W circular ploarizer.

http://SNC1923.smugmug.com/photos/256787707_qU9uB-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=256787707&ImageKey=qU9uB)

The polarizer here is adjusted for maximum saturation of the sky. Clearly, it's too dark.

http://SNC1923.smugmug.com/photos/256787559_gmVLq-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=256787559&ImageKey=gmVLq)

Roughly the same shot, backing off on the polarizer quite a bit. Sky is still unnaturally dark, but it is a more realistic photo.

http://SNC1923.smugmug.com/photos/256787815_pfqhA-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=256787815&ImageKey=pfqhA)

Same thing: Too dark.

http://SNC1923.smugmug.com/photos/256787935_ZGHJs-L.jpg (http://snc1923.smugmug.com/photos/newexif.mg?ImageID=256787935&ImageKey=ZGHJs)

A change in orientation and in the adjustment of the polarizing filter, resulting in a more naturalistic image. Click for EXIF. The exposures in the first two are equivalent; in the second two, identical. The last two photos are underexposed, the LM being fooled a bit by the white rocket. Had I to do it again, I'd add +2/3 EV.

Vignetting (dark corners) is not apparent to me in any of these shots, but might be against a lighter background--modern lenses vignette quite a bit. Processing programs like LightRoom even have settings to deal with it.

[bricciphoto]

Those are good examples Tom. Thanks for helping out!!! :wave

Note the rocket in Tom's last two pics is fighting underexposure while the sky is less saturated (similar to my snow example above). This is very difficult shooting territory even for a pro as it's really pushing extremes into one exposure.

Here, this is Velvia and I'm pretty sure no filtration at the Bonneville Salt Flats. Yucky black sky. There's probably 7 stops difference from the top of the frame to the bottom--maybe more :p .

http://bricciphoto.smugmug.com/photos/256794360_Xqiwm-L.jpg

(Sorry for beating this nuance to death. :rolleyes )

[bmwdean]

Those are good examples Tom. Thanks for helping out!!! :wave

Yucky black sky.
http://bricciphoto.smugmug.com/photos/256794360_Xqiwm-L.jpg

I guess I am all washed up. I like it. Has an other-worldly feeling. Neat.

[bmwdean]

I guess this photo of a 1952 BMW R51/3 would qualify as a yucky black sky :)

[bricciphoto]

Here's the same scene with a better exposure. Almost makes me want to go out and shoot some positive film again. ;)

http://bricciphoto.smugmug.com/photos/257788643_zWAbn-S.jpg

[bmwdean]

Here's the same scene with a better exposure. Almost makes me want to go out and shoot some positive film again. ;)


I plan re reshoot my "yucky black sky" photo above again without a polarizer, and will post the result. The polarizer can, I confess, over-darken the sky, and does over-saturate the black on the motorcycle. I will be interested to see how the same photo without the polarizer changes things.

BTW, the photo with the white motorcycle seems to come out better with the polarizer than the black motorcycle.

[bmwdean]

Here is the similar view show with no filters at all. Compare to black sky above. I confess that I like this better.

One should be careful using a polarizing filter. As Ben said, it can turn your sky black. It can also over-saturate colors, causing then to become too dark, and can alter the colors. And, depending on the quality of the filter, it can reduce the crispness of the resulting image. I noted that my Hoya circular polarizer did reduce slightly the sharpness of the details on the motorcycle, such as the BMW roundel, and tends to make everything slightly greener. Perhaps I need a higher quality filter.

I see they can be pricey -- http://tinyurl.com/3cos3y

[bricciphoto]

Here is the similar view show with no filters at all. Compare to black sky above. I confess that I like this better.

One should be careful using a polarizing filter. As Ben said, it can turn your sky black. It can also over-saturate colors, causing then to become too dark, and can alter the colors. And, depending on the quality of the filter, it can reduce the crispness of the resulting image. I noted that my Hoya circular polarizer did reduce slightly the sharpness of the details on the motorcycle, such as the BMW roundel, and tends to make everything slightly greener. Perhaps I need a higher quality filter.

I'd call this one stunning and/or beautiful. Very nice. It has a timeless feel to it. :bow

What direction is the camera facing? East? I'm trying to envision this same shot taken during the golden hour.

[bmwdean]

I'd call this one stunning and/or beautiful. Very nice. It has a timeless feel to it. :bow

What direction is the camera facing? East? I'm trying to envision this same shot taken during the golden hour.

Thank you, Ben.

Timeless, perhaps, because the motorcycle is 56 years old :)

I am facing west.

[rdsmith3]

The only issue with CP filters is when using with a wide angle lens. The sky will be unevenly filtered. I like the effect, but not everyone does. Here is a shot with a Canon 10-22 mm lens all the way at the wide end. No photoshop -- this is straight out of the camera.

http://rdsmith3.smugmug.com/photos/142823293_TAbZa-M.jpg

[MLS2GO]

Shot it with my D70. Polarizer or not, what do you think? I can't remember.

http://mls2go.smugmug.com/photos/260404220_gkVmT-XL.jpg

I'm thinking not.