A.J.R. Loc: Devon, UK

I am able to understand something said as an opinion that might be incorrect but to blatantly give wrong information as a fact (“I've ruined great lenses with crappy CPLs”) is very confusing to a new member, and might lead them to question legitimate answers.

John N Loc: HP14 3QF Stokenchurch, UK

The best guide I've found by a long mile!

http://www.cambridgeincolour.com/tutorials/polarizing-filters.htm

As you have found out, twisting the filter maximises the effect. CPL's work best when your shoulders are in line with the sun - and if your lucky with your timing when the sun is about 45° of the horizon.

gtheodore Loc: Fort Collins CO

Hi Megan

Did you check your histogram shown on your camera's LCD? The right side of your histogram should be close to the right edge of the LCD display. If you're shooting in Av mode, use your camera's exposure compensation to "move" the histogram. If it's too far to the left (underexposed), increase the exposure compensation (+); if too far to the right (climbs up the right side), decrease exposure com (-). So, to add light, it's (+); to reduce light it's (-). Easy to remember.

Hope this helps.

hassighedgehog Loc: Corona, CA

FYI The reason there is no gauge marks in a polarizer is that what is needed depends on the direction the camera is pointed, the angle to the sun, etc. Don't have one with me now (at Starbucks) but, maybe they have the plane of polarization marked? If not, that might be useful.

Moose13

Attached (I hope) is a optimized version of your image of the boy in red shirt at beach

Pixljockey Loc: Southeast Pa.

Someone brought out at the beginning of this thread that checking the "store original" box would allow members to see the metadata. Where would you be able to view this?

CHG_CANON Loc: the Windy City

Moose13 - as a new user, you should be mindful of the rules about editing and reposting images. Simply attaching a file is not a default invitation from the original photographer to modify and repost a new version of their image. The OP should state this invitation or you should explicitly confirm. The applicable site rule comes from the FAQ at the top of the Photo Gallery:

- Please do not edit and re-upload other people's pictures without their explicit permission. In other words, you may not open someone's topic, download an image, edit it (that includes adjusting settings, cropping, adding/removing visual elements, etc.), re-post it, and say "here is a version of your photo that I like better" unless they specifically ask for it.

https://www.uglyhedgehog.com/t-426-1.html

srt101fan

Great editing job!

E.L.. Shapiro Loc: Ottawa, Ontario Canada

I hope the OP has not run off screaming. So many conflicting scientific theories and arguments and semantics as to world usage. WOW!

I hope she realizes that PHOTOGRAPHY is a VISUAL art and craft that is attached to many technical principles but sometimes using the old eyeballs and hands-on experimentation is the best learning method.

It's great to learn all the science- the why's a wherefores of how things work. Sometimes written or verbal instructions or directions can be helpful but oftentimes visual demonstrative practice sinks in faster, especially in folks who are VISUALLY oriented more so than auditorily oriented. It's not that VISUAL people are illiterate of hearing impaired- they just respond faster and more effectively to what they SEE as opposed to what they read or hear.

Back in the era of film photography, perhaps all the theory was more important when working in the field. We had to depend on our aptitude to pre-visualize exactly what MIGHT appear in the film and the final print. Nowadays, we not only see our composition in the viewfinder but we can verify, assess and adjust exposure and effect almost instantaneously.

Visavis POLARIZING FILTERS- not only will we see the effect in the viewfinder but we can further asses it on the LCD or live screen. It's just a matter of knowing what to look for and what and how much effect you prefer. If your angle to the light is ineffective, you will know immediately in that there will not be the desired effect.

So here I am sitting in my office. I shot a few test images of some leaves on our house plant, the detail on an antique chair and some reflections in a glass display unit. One image with the CPL filter in place and one without.

So...the top image of the detail on the old chair is without the CPL filter- the bottom on is with the filter at maximum effect. The window light striking the patina of the wood is causing glare due to the angle of incidence. With the filter in place the image now reveals the grain of the wood and the warmth of the original stain. There seems to be more relief in the pressing. This was auto exposure and autofocus with no processing except to make the college.

The leaves on the left are without polarization so the ones on the right, with the filter in place and rotated to maximum strength, show less gare and slightly more saturation.

The glass showcase pane on the left image shows a reflection of the window- no CPL filter. The example on the right is with the filter in place- most of the reflection is gone, there is more saturation in the blue backing paper and the black wooden frame has less glare.

These are not artistic images- they're the kinds of experiments that should be done to put your polarising filters through its paces before taking it out in the field. You can go for more extreme effects or anything in between.

Those angles do make a difference, for example, you may find that the filter in one rotated position eliminates some glare on a sloped roof but may render the windows too dark so you have to decide which to favor. You may prefer the image of leaves with more intense reflections. On a bright sunny day, you may want a "picture postcard dramatic sky" or leave it to be more pastel- you rotate the filter and decide what you want to do.

Your CPL filter will cut through many unwanted reflections but it will have little or no effect on polished metals and most metallic reflections.

The ANGLE thing sets in when attempting to darken a skyscape when a wide angle lens is used or when you zoom to a wide angle setting. You may find an uneven sky effect but that is not a defect in the filter or the camera.

The "OFFICIAL" word from back at photography school says: "A polarizing Filter darkens clear sky at 90 degrees to the sun without affecting the gray-tone rendering of colors. Rotate the filter to find, VISUALLY the angle that gives the maximum effect.
In real life, there are many in-between effects and many other usages. it is not a cure-all to every issue of unwanted glare.

To avoid any confusion in the event of disappointing results and being able to track down any problems through logical troubleshooting, make certain that your camera is operating properly as to program settings, any exposure compensation, whatever automatic or manual exposure modes or settings are accurately employed and that you auto or manual white balance and focus setting are working WITHOUT THE FILTER. When the filter is employed everything else should still work in automatic modes. If you are shooting in manual mode, you in-camera meter should still factor in the filter.

Any filter you use should be of the best quality that you can afford. Anything you place in the light path has some effect on the image quality. All filters add additional surfaces that can be affected by flare, that is, light striking the filter or lens and reducing contrast. Better filters have a coating to mitigate these issues, however, the use of a good lens shade is advisable. High-quality CPL fites are also mechanically sound in that the will rotate smoothly and not tend to deform or get jammed onto the threads on the filter mount.

Architect1776 Loc: In my mind

Second question:
Light is at many different angles so a polarizer must rotate to the point where the light is polarized to your taste. So there is no scientific base point as light varies depending on source and where it is coming from and other factors.
The purpose of the filter is to get the effect you want. There is no book saying what is correct because that is subjective and thus no correct answer. Some might claim there is but there really isn't.

burkphoto Loc: High Point, NC

Many applications can view metadata — the EXIF file that is part of every raw and JPEG recorded.

Raw files are wrappers that contain an array of unprocessed, digitized sensor data, plus a JPEG preview image file processed by the camera (or two or three in different sizes), plus a table called the EXtended Information File (EXIF).

JPEGs are wrappers, too. They contain a small preview thumbnail image, a much larger image file, and the EXIF data, which is the metadata, or “data about data.”

EXIF is the table of detailed exposure data. Many image viewers and editing software applications have an option to read it. Apple Preview on the Mac is a good example.

traderjohn Loc: New York City

Well, Megan, after all this what have you learned? I think it boils down to buy a good filter, not one that will break the bank. practice with it and then you will see the difference.

Pixljockey Loc: Southeast Pa.

Thanks burkphoto, I use Lightroom for editing, but I don't see a lot of metadata there, just a small amount. I usually use the pc or an IPad to view this site, do I need to get a program specifically to view metadata?

CHG_CANON Loc: the Windy City

If an image has been processed by an Adobe tool, much of the propriety vendor-specific data will be removed. It's always better to make an UHH attachment of the JPEG straight from the camera, particularly when trouble-shooting exposure and / or focus issues. Then, for Canon bodies, one can use the Canon DPP software to analyze all the EOS-specific details, including the locations of the active AF points.

If you do some google searches of EXIFTOOL.exe, this command tool can be used to dump all of the available EXIF values to a text file. The command would be:

EXIFTOOL.exe <jpeg-filename> -list -EXIF:All -sort > <text-file-name>

You can then open the <text-file-name> in a text editor like Notepad and scroll through the values. I did an analysis prior that shows about 300 values from an EOS body will be removed by Adobe when the JPEG file is exported from Lightroom. Most of these 300 are of little use to the general public, but the LR-version can no longer be used in DPP to view details of the exposure and AF points.

burkphoto Loc: High Point, NC

You can... Many are available for Windows. Right-clicking on a file in Windows Explorer may allow you to view metadata as ‘properties’.