I've bought polarizers for virtually every camera I've ever used for the last 40 years, including video cameras, but rarely use them. Under certain circumstances, they are invaluable--shooting through glass, avoiding surface reflections, and artificially darkening blue skies as shown in your picture (if that's what you want to do). The picture on the right may look more appealing, but the one on the left is certainly more accurate. The main drawback of using polarizers is that you lose roughly 2 F-stops of light--not a problem in bright sunlight but can become an issue otherwise. There is also the potential for vignetting at wide angles. It also requires that you rotate the filter for the desired amount of polarization which means you have to remove your lens hood unless you have a hood that screws into the filter itself. For these reasons, I seldom use one unless I need to deal with reflections.

wwaag

+1 all wwaag wrote...

The picture on the right may look more appealing, but the one on the left is certainly more accurate[

accuracy in video surely an oxymoron ;-)

I'll be shooting swim meets on cloudless days. There is plenty of light for that activity. As inaccurate as it might seem, the sky in my backyard rarely appears as blue on my videos as I observed it.

Then, we are having to deal with my eyes.

I'll be shooting swim meets on cloudless days.

A polarizing filter in that situation will definitely be your friend.

the sky in my backyard rarely appears as blue on my videos as I observed it

In my limited experience, most consumer cameras and camcorders tend to overexpose. For stills, I routinely set EVF compensation to -1/3. It's always best to underexpose since you can compensate in post. For your situation, you may want to underexposure even more. Those highlights will definitely "fool" your camera's exposure metering--similar to photographing inside a forest in bright sunlight. You just need to experiment.

wwaag

I've observed that this camera tends to over-expose. When I'm awake, I do set the exposure to manual from -1/3 to -1. what happens when exposure is set to automatic. was all manual. Same camera.

I just bought a Neutral Density 0.9 filter and the polarizing filter and began experimenting yesterday.

I just bought a Neutral Density 0.9 filter and the polarizing filter and began experimenting yesterday.Oh yes . . . I started with a pola and then quickly ran through a range of NDs including GRAD NDs.

Open the Iris FULL and use the NDs to stopdown for Shallow DoF. These 2 analogue bits of kit re-inspired my digital captures and to use filters. This chap has been my inspiration - Joe Cornish. Seek out ANYTHING by him on the INTERNET, consume and relish it all:



More Joe with LEE Filters

Joe's own Website

It's a great path you've started on . . . . .

Grazie

Auto-exposure is probably the biggest telltale sign that an amateur is at the controls. And of all the things we can tweak in post, blown-out highlights are the least fixable. That, and clipped audio.

As to the top photos and which is 'accurate', if you're a professional, it's your JOB to make the footage you're shooting the most pleasing to the client's eye. Sure, amateurs don't carry filters, white balance cards or professional audio gear with their cameras. But that's why they weren't hired.

@DGates, if I had the choice, I'd have a go at Clipped Audio any day, over blown video!

Grazie

Well sure, if you HAD to pick. I'd rather not have either.

I have this one and it is really high quality


http://www.amazon.com/Kaesemann-Circular-Polarizer-Multi-Resistant-Coating/dp/B0000BZLAC/ref=sr_1_3?ie=UTF8&qid=1431871279&sr=8-3&keywords=cpl+filter+77mm

Thanks Grazie for exposing me to this type of filters. It is fascinating. I watched all of the demos.

@ Bruce

I bought this one.

@wwaag

"The picture on the right may look more appealing, but the one on the left is certainly more accurate." *

After shooting a number of swim meets with polarizer and ND filters in place, I've found that I never go for the look on the right. On my camera, I think the look on the left looks a little washed-out. I usually set up the camera facing the same direction as I will be shooting with some blue sky in the shot. I lock the exposure level, then I rotate the filter to both extremes watching the LCD screen. I then pick a position somewhere in between the two extremes and note the mechanical position on the lens in case it gets bumped and I have to recover quickly. Because the earth is always moving, I set up before each and every heat. At some times throughout the day, the filter doesn't help a bit because of the angle of the sun. I can't always change sides of the pool.

I appreciate your observations.

The exposure got away from me on Event 23-7 The Do-Over. While the event was being re-queued the sun got brighter and I didn't set up the exposure again.

* 2018 edit for Magix web site text formatting.

@john dennis

John, thanks for sharing. I think I can tell that you're the proud Grand-pa-pa. I must admit I'm a bit envious. Having looked at your YT video, I can see that you've got a really tough shooting environment. My only suggestion would be to try the auto-exposure mode of your camera (I'm sure you've probably done that already). The exposure seems spot on for the beginning and end, but is really over-exposed during the actual swim part. The highlights seem really blown out, even on the first clip. As you pan down the swim lane, the camera should be able to smoothly compensate for such changes in the lighting. You might even try setting the exposure compensation to -.5 or -1. You can usually work with underexposed video, but once the highlights are blown, there is little that can be done. You might also try a little stabilization if you have Mercalli. Having said that, I think we (especially hobbyists) oftentimes pay too much attention to getting it "just right" and forget that content is paramount. I suspect that the important others will probably care less, if its a little over-exposed or shaky in places. Creating those lasting memories is what it's all about--at least IMHO. Again, thanks for sharing.

wwaag

Who wants "accuracy" if you then feel the need to frig around with it afterwards to make it "right" !

geoff

John brought up a good point that I thought of when I saw your original post. The angle is very important. I think most people will be shooting with the sun at their back, which is when an ND will work, but if you're shooting with the sun to either side the effect will be minimal, and if you're shooting into the sun then the filter will virtually do nothing at all.

Adam,

I think the angle doesn't matter with an ND, but it does with a Polarizer filter.

(unless you are referring to a variable ND filter using two polarizer filters, then it might make a difference)

Duh... I am an idiot, I totally mean polarizer... thanks for pointing that out.

Don't all rush at once . . . .

Question/s: Does a Variable ND, using this Polarizer twist effect, ALSO produce a Polarizing effect or NOT? Or just act as a Variable ND resulting in lower light levels?

@Adam_L. : Please check out this further bit of superb info at Cambridge Colour.

Grazie

Here is my guess:

The polar sensitivity of a polarizing filter to the angle of polarized light will be something like a figure-8 microphone or a dipole antenna.

One polarizing filter will only allow light more or less polarized to its axis (or 180 degrees to it) to pass through. Adding another filter with the same axis angle will do likewise, and so the light will still be polarized, with little further loss.. As you rotate one lens, light predominantly polarized at midway between the two axes will pass through with least loss.

Pardon my ignorance of correct terminology.

@PD: " As you rotate one lens, light predominantly polarized at midway between the two axes will pass through with least loss."

Sure, and this will still remove the "shine" of leaves; allow me to "see" the fish swimming below the surface and see through glass fronted cabinets which were reflective. Yes?

My still stubborn brain is wanting to ask: Would I need (this is the only way or context I can think of asking this question) a further Pola to be able to do this? OR am I kinda "stuck" with what the Pola Variable ND parameters that I had been given? Am I restricted to and by the Variable ND and hence the angle of attack of the light source - Sun, internal lighting etc - given by that Variable ND?

Grazie

interesting question indeed grazie...

do you have a variable nd? if so, try a very simple test - shoot a reflection in a window whilst in auto and see if the reflection disappears as you turn the filter...

I believe variable ND filters do not work as polarizers.
I cannot find out for sure how they prevent this but probably by using a 1/4 wave plate before the first linear polarizer. In other words they depolarise the light before it reaches the first polarizing filter.

Bob.