A Newbie's Polarizing Filter Questions

[Kemo53]

I was disappointed recently with my shots on a cruise to the Caribbean. Many outdoor shots were much too bright... especially those at distance ... despite playing with various apertures, EC values and the like on my D5100 and feel I spent much too much time PP trying to compensate. I have been told polarizing filters are important in such circumstances but know there is a difference of opinion as well. Thus the question(s):
What do you think ?
Circular or Cokin P series (box style) ?
Thanks

This photo is actually from last years cruise and not this years. All photos from this year are already deleted or heavily PP'ed. Thanks again

IMG]http://i43.tinypic.com/b705xs.jpg[/IMG]

[Manfred M]

It would be useful to see examples of your images to help judge why they appear to be too bright. It could be as simple as your computer screen being turned up too bright. Your camera's light meter will try to adjust everything to an average value and can be fooled by non-average scenes.

Polarizing filters have some very specific uses; reducing glare from non-metallic surfaces and deepening the colour of the sky if you are shooting at around 90 degrees from the position of the sun. By themselves they increase exposure requirements a bit. They are not a panacea, and have downsides as well as the uses I've mentioned.

I find the round polarizers most useful and I rarely remove them when shooting outdoors. I do have rectangular filter system (Lee), but still use round filters for polarizers because they work better for me.

[NorthernFocus]

As mentioned by Manfred, polarizers only help if at sharp angles to the direction of light or to remove glare from wet surfaces (like rocks on a stream bank). One advantage to the Cokin system is that you can buy a single CP filter and then get adapters for the Cokin system for different lens sizes. Also, many of the conditions that require a CP filter also lend themselves to graduated density filters or neutral density filters which you can also get to fit in the same Cokin holder.

[Polar01]

Kemo53: as Manfred has stated it would be best if we could see an image with the problems you describe that you have not played around with in post. I maybe that a Polarizing filter would be of help, or if it pilot error, so to speak. So read up on how to post an image and let us see what might be the problem.

Cheers:

Allan

[Geoff F]

Generally speaking, I haven't been over impressed with polarizers so I rarely use them now.

In the days of film, they were sometimes useful particularly for deepening sky colour etc. Rotating the ring varied the effect between yellow and blue. But I now do this by shooting Raw and adjusting the White Balance during conversion.

If shooting with auto settings a polarizer can help to darken the scene and prevent over exposure.

But I normally prefer to meter around the scene then work out a suitable exposure, to fit my required aperture setting and shoot with manual settings.

Or when using aperture priority or shutter priority options I use a bit of exposure compensation.

These methods do require a little bit of experimentation and expertise though. But should quickly become second nature and not take a lot of time.

There is always a risk with auto settings, including the semi auto options, that Evaluative metering (name may vary) will miss out on some small areas of over/under exposure.

[kdoc856]

Kemo,

I shoot mostly landscapes, and I start almost every shoot with a circular polarizer already in place. They are a huge help in blocking reflected light that will rob you of detail and color saturation. They are absolutely crucial on most shots that have water anywhere in them, and they can help control (decrease) light intensity.

Whether you prefer Cokin or circular is largely personal preference (I am lazy and impatient so I use circular), but don't waste your money on cheap ones, i.e. less than $125 US. The cheap ones really don't help much at all under any circumstances, and will an ugly greyness to your shots.

[rpcrowe]

Kemo53: You mention that you have exposure problems, "despite playing with various apertures, EC values and the like on my D5100"

What exposure mode or modes are you generally using for your shots? Most of todays DSLR cameras are pretty darn capable of achieving good exposures...

I would be willing to bet that use of a CPL or non-use of a CPL would have no bearing on your faulty exposures...

I suspect that many inexperienced photographers (I assume that you are inexperienced) have exposure problems when they try to take control of the exposure and not letting the camera's auto exposure control the exposure. This is especially true when inexperienced photographers read postings by more experienced photographers that manual exposure is the way to go.

I am certainly not advocating using the "A" or full automatic shooting system of any camera but, "P" or programmed exposure as well as "A" aperture priority exposure will usually place you right in the ballpark exposure wise.

I would just about guarantee that if you set your ISO to 200 and your exposure to "P" (or whatever Nikon calls the programmed mode) you could step out your door on a reasonably bright day and expect very decent exposures. If your camera doesn't deliver good exposures shooting this way, there could be some problem with your camera. If I was shooting at ISO 200 on a sunny bright day and my camera was giving me exposures which varied greatly from 1/200 second at f/16 (or any other equal combination of shutter speed and f/stop) I would definitely look into whether that camera is functioning correctly...

Another way for an inexperience photographer to ensure that the exposures on any trip are decent is to bracket the exposures. Unfortunately, although some of the Nikon camera models have a better AEB system than some of the Canon cameras (which have only a three shot AEB capability); the entry level Nikons are far behind the entry level Canon cameras in AEB capablity.

Experienced photographers may sneer at AEB but, it is far better to use AEB as a crutch during important occasions like trips until you get to the point of experience in which you can pretty well be confident of your exposure in just about any venue. After all, it is what kind of images you end up with rather than how you obtained the images that is important. It must be frustrating to arrive home with less than decent exposures.

Another parameter which "could" cause faulty exposure is if you are choosing the wrong area/areas from which to measure your exposure. On Canon cameras, evaluative metering will give correct exposures in many general situations. Spot metering will give correct exposure in some specific instances but, can cause bad exposure if used as a general practice.

Additionally, if you are shooting extremely bright (snow type) scenes or extremely dark (black cat in a coal bin) scenes, you need to adjust the exposure to compensate by adding exposure for the snow and subtracting exposure for the black cat...

This brings me to another thought, shooting in RAW will allow you more control over post processing your images than will shooting in JPEG.

[DanK]

Kemo,

Your photo did not upload correctly, so it is very hard to know what the issues are. However, you mention exposure problems. While polarizers can help with certain specific exposure problems, in particular, glare, they are not a solution to most exposure problems. Most exposure problems in a context such as the one you describe are the result of either (1) ineffective metering (e.g., wrong metering mode, metering off the wrong part of the scene, lack of needed exposure compensation), or (2) too much dynamic range in the scene. A polarizer won't solve these problems. Post a few shots, and folks here might be able to help.

Dan

[tclune]

I was disappointed recently with my shots on a cruise to the Caribbean. Many outdoor shots were much too bright... especially those at distance ... despite playing with various apertures, EC values and the like on my D5100 and feel I spent much too much time PP trying to compensate. I have been told polarizing filters are important in such circumstances but know there is a difference of opinion as well. Thus the question(s):
What do you think ?
Circular or Cokin P series (box style) ?
Thanks

This photo is actually from last years cruise and not this years. All photos from this year are already deleted or heavily PP'ed. Thanks again

First, a couple of small points. First, you messed up the code on the image. Put back the initial '[' before the "IMG]" and your photo will appear in your post. Second, people normally use the term "circular" when talking about polarizers to refer to the kind of polarizing, not the shape of the device. My guess is that Cokin uses circular polarizing like everybody else in the digital world. Linear polarizing can cause problems with some focusing systems AIUI.

Now, I would recommend the traditional screw-in polarizer over Cokin -- because you can use your lens hood with such a polarizer, and the reason you want to use a polarizer is to deal with bright sun (there are other reasons to use one, but this is a common one.) The screw-in type can be a little fiddly with a hood on the lens, because you need to rotate the filter for maximum effect after you've composed the shot. But I have never found it too difficult, and a hood is very important in cotrolling glare on the lens.

Second, I find the polarizing look very unpleasant and artifical on large expanses of sky (the sky is dark blue at maximum effect -- 90 degrees off-axis of the camera/sun -- and gets progressively more normal as you approach that axis.) So I would not use a polarizer for this purpose on a lens with a field of view larger than about 45 degrees, and the narrower the better for this purpose. So you don't need a polarizer for every lens in your kit. I use a polarizer on my standard zoom and my tele zoom, and I bought them in part because they have the same diameter and will take the same filter.

FWIW

[Manfred M]

First of all, the image looks quite normal too me. A sea scene usually has a bit of haze and that can easily be handled through either some custom camera settings (increase the contrast and saturation) or a 10 second tweak in post production.



I can't agree with Tom on using a polarizer. I'm with Kevin and rarely shoot outdoors without one. One can go a bit crazy with a polarizer, but it is easy to dial it back a bit just to give the clouds and sky a bit more pop. That being said, it only works in certain directions and it can be problematic with a wide-angle lens as you can get banding in the sky.

[Kemo53]

First, thanks for the reply. I am absolutely inexperienced as you so tactfully replied. I typically shoot in P mode with aperture changing my initial go-to. My one and only photography class... last summer when I got the camera ... harped on us that this was the preferred way to go. He downplayed other options when I asked questions specific to my typical shot, i.e., daytime landscapes and ships in the distance. I have gotten in the habit of using the P and aperture combo and like it in general. I normally only adjust ISO for dim lighting circumstances and suspect this is wrong. Since haze is often an issue, I read that circular polarizers would help. Thus the post.

[rpcrowe]

Your image is a good example of the problems shooting a landscape (or in this case a seascape) using a wide angle lens. What a wide angle landscape/seascape image often contains is a vast amount of uninteresting foreground (in this case sea) and an equally uninteresting expanse of sky.

This is can be compounded by placing the horizon dab center which is another way to create an uninteresting image.

IMO the subject of this image is the spit of land and I would crop it into a pano type format, placing the horizon either 1/3 from the bottom or 1/3 from the top.



I think that in this case, your image might very well have benefitted from the use of a CPL flter which may (depending on the angle of the sun) have darkened your sky and accentuated the clouds. It may (again depending on the sun's angle) have reduced the impact of haze and resulted in a clearer image. BTW: The CPL reduces reflection from airborne particulates which helps penetrate the haze...

A downside of the CPL is, when using an altra wide lens, the polarization is often not equal across the expanse of the image. However, the lens usually has to be pretty wide for this to impact. It seldom happens with a kit lens on a crop camera...

I don't know if you use a lens hood but, I strongly recommend using a hood in all shooting - especially out of doors...

However, all is not lost. Some creative cropping, added contrast and virbrance as well as sharpening can add to this image. I have not worked on the sky in post processing but, that could also be improved in PP...

[Glenn NK]

Kevin:

Welcome to the forum - a good learning place.

I pulled up your photo into Lightroom, and the first thing I checked was you exposure.

The bad news is that it is not overexposed, so something else is wrong. You are either viewing and judging your images on the camera LCD (which is a terrible way to judge images because camera LCDs vary all over the map), OR you are viewing your images on a uncalibrated monitor (which isn't displaying it the way it actually is).

The good news is that it is not overexposed. In fact you could have exposed the image about one stop more, as this would capture more information in the details. This may sound confusing and I could explain more, but I suggest a slow learning curve on which you learn the basics first.

Glenn

[jcuknz]

My first comment is did you just have the CPL on the lens for every shot or did you rotate it for best effect for every shot?

I think Richards comment should be engraved on the back of every newbies' camera ..
I suspect that many inexperienced photographers (I assume that you are inexperienced) have exposure problems when they try to take control of the exposure and not letting the camera's auto exposure control the exposure. This is especially true when inexperienced photographers read postings by more experienced photographers that manual exposure is the way to go.

You should have a reason to use M .. and for me this is a recognition that the automatics hasn't got it right ... which is rare, though usually the recognition comes from the camera telling me it knows it isn't right with its 'blinkies'. Though others use the histogram.

As for the question of circular or box polariser ... with the circular you either need a modified lenshood with room for a finger to rotate the CPL or remove the lenshood. The box filter doesn't normally have a lenshood, though they are available, and the genuine Cokin A holder has a special slot for the Cokin CPL which has a knurled rim so that one can rotate it from outside the holder ... at least it did way back as apart from myself I have not read any comments and my gear was bought at least two/three decades ago. I have a couple of 'clones' which do not have the CPL slot, only slots for rectangular filters and hood.

But none of this gear gets used these days as I rely, sometimes mistakenly, on my editor to achieve the result I saw. Adapting a lenshood is one of my 'projects' which I may or may not get around to. It is a hole/slot on the underside of the hood.

I never delete an exposure but keep everything in an archive folder and only delete dud shots from my working side of the computer. Because some time in the future I might want to, and do, revisit in light of greater knowledge, ability, and new features in editing. My archive folder is in the hard drive from my previous machine and sitting in its own box beside the computer.

[Kemo53]

Thank you all for the replies. I am pleased at so many replies and enjoy the difference of opinion(s) some posts offer. As to generic comments about my "newness" I have never been shy about it. I still take some losers but most are winners and I enjoy banging away at it. I may have mis-worded my original post, however. I rarely shoot in "A" and almost as rarely shoot in "M" mode. The "P" mode is my standard and thus the camera is making a good deal of the decisions in the shot; I am generally happy with the results of this arrangement. I always use a lens hood and I own absolutely no filters of any kind, and since time is often not a factor I also enjoy changing lenses as well. I noticed while window shopping this site that many recommendations do not require output of great sums of money, and the thought of quality people offering opinions with no bias appeals to me. Thank you all again, and thank you for your kindness. Kevin