dull pictures with polariser

<p>I went to the track to take pictures of a friend in his newly painted car. The sun was bright, and I was getting reflections, so I tried using a polariser. When I got home, I noticed that the pictures I took with the polariser were dull. I think that the polariser I'm using is a good one (B+W) and the images are sharp, the colors are just not what I expect. Does anyone know if this is normal ? Are there photoshop tricks to restore the brightness?</p><div></div>

<p>You don't mention if you were using a digital camera...but with digital or film if you have an SLR camera you should be able to turn the polarizer while looking at a scene and watch its effect.<br>

Polarizers don't 'work on everything'...they depend on reflections, your position in relation to the sun and the reflections, etc.<br>

You should be able to easily fix the pix with a Curves or Levels adjustment in Photoshop.</p>

<p>I might add...you didn't say how you measured exposure, but if you were in manual mode and didn't change exposure when you added the polarizer the exposure would be off. The polarizer will definitely have an effect on light reaching the film or sensor and adjustments have to be made...</p>

<p>Thank you Jack for the quick response. I'm using a D300, and the exposure in the sample photo could maybe use an extra +0.5 EV. I set the filter at an angle that best decreased the reflection from the windshield. Is this typical of the results you get with a polariser?</p><div></div>

<p>Not at all...in fact the photo without the polarizer looks dull to me as well...the polarizer should deepen the colors, but with the proper exposure the photo should look better and not worse (assuming you're at an angle where the polarizer can make a difference).<br>

Here's a link that might help...<br>

<a href="http://www.great-landscape-photography.com/polarizing-filter.html">http://www.great-landscape-photography.com/polarizing-filter.html</a></p>

<p>One last caveat...with a digital camera you need to use a circular (not linear) polarizing filter to allow the TTL metering system to work properly.</p>

<p>After a little Curve and Level adjustment, you have something perfectly vibrant. JR</p><div></div>

<p>The polarizer is like a grate that blocks waves of light that are not parallel to the slits in the grate. You oriented yours to block the waves of light reflecting off the windshield, which it did. Good. <br>

It also blocked all the other light waves in the scene that were oriented parallel to those reflecting off the windshield. Many of these are specular highlights which contribute to the contrast of the scene: you'll note that the specular highlights remaining in the polarized scene are quite small and focused, and the color saturation in the brightest part of the finish is quite high without the veiling reflections which are present in the unpolarized scene.<br>

As to whether this is a bug or a feature, tastes differ. Simple enough to pick up the contrast a bit with the gamma slider in a Levels adjustment layer, or a slight S-curve in a Curves adjustment layer, and that will really tell you what you've got:</p><div></div>

<p>Try shooting with the polarizer in different positions. You'll probably find that partial polarization works better.</p>

<p>I notice you said the pictures were "dull" rather than dark so I'll base my answer on that. </p>

<p>Looking at where the shadow of the car falls, you were in the right position (in relation to the sun) to get the maximum polarization effect. What may have happened while you were concentrating on trying to remove the reflections from the windshield is that you didn't pay enough attention to the reflections and specular highlights on the paint of the car and inadvertently removed them along with the windshield reflections. That could certainly cause the car to appear "dull" (in addition to the picture being underexposed). Cars can be a tricky subject when you're using a polarizer because they can have such a dramatic effect. For example you might polarize out a reflection of a tree from the hood of the car, giving the paint a rich look, but at the expense of not removing any glare at all from the window. Or you might get the tree reflection out of the hood but end up increasing the reflection of the grass towards the bottom. Or you might remove all the reflections from the paint, but none from the window, or vice versa. Often it ends up being a compromise. </p>

<p>If you have the time, frame your shot and then spin the polarizer around slowly a few times and watch various areas of the car as you do. You should then be able to notice not only where the reflections are, but also how they get removed/accentuated as you rotate the polarizer. After a couple of turns you should also be able to decide which reflections are the most objectionable and remove them and take your shot. Once you've taken your shot check the histogram and adjust your exposure as needed based on that.</p>

<p>Stanley - You've captured a nice image. However, unlike the past, when the film chemists and the processing labs were responsible for producing attractive color and contrast (assuming the exposure was correct), now, with digital cameras, the responsibility for adjustment of these and many more parameters falls essentially completely on us, the photographers. IMHO, a high level of familiarity with Photoshop (or equivalent) is now essential for all but the most casual photographers.</p>

<p>For example, I imported your jpg image into Adobe ACR, and literally, in less than 60 seconds (less time than it took me to type this message), produced the version attached below. Once you experience for yourself how much better your images can look with even a short session in Photoshop, I doubt you'll ever go back to a photographic life without PS. Unfortunately, there is one very big fly in the ointment: the steep learning curve to become truly proficient at PS. Don't despair. As the previous posters showed, you can do a lot with just the simplest tonal and color correction tools, eg, first levels, then hue/sat, then curves.</p>

<p>There are probably thousands of books on Photoshop that will get you started on the fun process of learning this program. One that I particularly recommend is "Adobe PS for Photographers" by Martin Evening.</p>

<p>HTH,</p>

<p>Tom M<br>

Washington, DC</p>

<p>PS - Apologies for the garish treatment. I wanted to clearly demo what can be easily done.</p>

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<p>Thank you for all the help.<br>

I own CS3 and have played with curves, levels, and hue/saturation, but have alot to learn.<br>

I'll watch what happens through the viewfinder much more carefully, and expose properly.<br>

Tom, how did you do that? </p>

 

<p>Hi Stan - <br /> <br /> Rather than type the name and value of each and every adjustment that I used, the most efficient way for me to send you my ACR settings for this photo is to send them to you as an ACR preset file. <br /> <br /> This is a *.xmp file that you can put anywhere convenient on your computer. You then tell ACR where to find it. You do this by clicking on the "Presets" tab in ACR (RH end of the row of tabs; looks like 3 horizontal sliders). You then go down one line (ie, to where it says "Presets"), and click on the tiny set of horizontal lines at the extreme RH end of that line. Select "Load Settings". You can then navigate to wherever you stashed my file and load it. Now you can read out each of the settings that I used. (Note, the above instructions are specific to the CS3 version of PS.)<br /> <br /> Unfortunately, I didn't save the the ACR settings that I used on your photo, so I had to regenerate them. Thus, the settings that I will send you in the XMP file will approximate the settings that I used before, but won't be exact (they are not very far off). In addition, please realize that I made adjustments to your image that I would *NEVER* use if there was a person in the image or there were other reasons for realism. I sensed that you wanted contrasty tones and vibrant colors, so that was my goal, not realism. For example, I'm not a fan of yellow grass, so I summarily gave the grass a lawn treatment and turned all the grass green ;-) by using the yellow hue adjustment slider in the HSL / Grayscale tab.<br /> <br /> I have also sent you an email with the same information. I could be wrong about this, but as I recall, the photo.net email system does not permit attachments to messages it originates, but it will give you my real email address. As soon as you respond back, I'll have your real email address and will send you the XMP file outside of photo.net.<br /> <br /> Please don't hesitate to ask if you have problems loading the XMP file or any questions about what I did.<br /> <br /> Sincerely,<br /> <br /> Tom M<br /> Washington, DC<br>

PS - I never actually went into PhotoShop "proper". All my tweaks were made in ACR and I resaved the file from there. I could have made equivalent changes in PS without going through ACR, but since it sounds like you are just coming up to speed in PS, I thought this would be a more gentle intro instead of having to learn about layers, masks and such.<br>

PPS - If you system is not set up to open JPGs in ACR, you will have to do so. I believe there have been several previous posts on this.</p>

To get the best effect from a polarizer, you should have the sun at a 90 degree angle. If the sun is behind or in front of you , it won't give you the proper exposure.

<p>Stanley,</p>

<p>To be honest, the first shot looks under exposed, as much as anything. Some of the other shots, look like it may have been a hazey or slightly over cast day, based on the shadows under the cars. it's hard to get bright pictures, when the lighting isn't bright. </p>

<p>As Don, who posted above me, said, the polarizer works best, if the sun is directly to your left or right. If it is coming at you, it doesn't work as well. Look at the angle of those shadows and see if you can tell where the sun was.<br>

The final thing to keep in mind is that as you rotate the polarizer, the color can get a different cast to it. If you over rotate, you could induce some blue to the picture.</p>

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