Quick question...

My Canon EOS digital SLR requires a circular polarizer, but what about the A1?

I've read here numerous times that a circular polarizer is not required on the A1. I don't recollect the specifics of the reason, but it fundamentally has to do with the difference between the way that DSLRs and CCD cameras work.

Save yourself a couple of quid and go with a linear.

Yes, the A1 does not need a circular polarizer.

In fact, many find that linear polarizers have a stronger effect than circular polarizers and are preferred if they can be used.

After posting this question, I was looking on the B&H web site and saw that it said circular polarizers are required for autofocus cameras. The A1 focuses through the lens, just like a DSLR, so why would it not require a circular polarizer?

Most DSLRs use beam-splitters (e.g. mirror) that require the use of a circular polarizer.

The XH-A1 does not use a mirror or other split-beam system.

When the info talks about "auto-focus" cameras, it is usually referring to still cameras, specifically DSLRs, not video cameras.

Polarizer (http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/filter/polarizer.html)
Polarizers (http://www.luminous-landscape.com/tutorials/polarizers.shtml)
Re: Why they're Idiots: (*Pics): Canon Talk Forum: Digital Photography Review (http://forums.dpreview.com/forums/read.asp?forum=1010&message=14720859)
Polarizer - Camerapedia.org (http://www.camerapedia.org/wiki/Polarizer)

Excellent! Thanks for the explanation and the links.

I love the circular polarizer on my A1. I shoot a lot of automotive stuff and using the circular polarizer allows me to erase reflections in the paint job, letting me see the detail in the paint work. But I don't always use it - sometimes a cool reflection is just the right shot.

I have a 77mm circular polarizer for my stills EOS camera and will probably just buy a step-down ring from 77mm to 72mm for the A1. I don't think I'll get any vignetting due to the not-so-wide lens on the A1.

You can use a circular polarizer if you have one on a video camera too; it's just that it won't do any more for you than a linear one and to spend more money for one would be a waste.

Most DSLRs use beam-splitters (e.g. mirror) that require the use of a circular polarizer.

The XH-A1 does not use a mirror or other split-beam system.

When the info talks about "auto-focus" cameras, it is usually referring to still cameras, specifically DSLRs, not video cameras.

Polarizer (http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/filter/polarizer.html)
Polarizers (http://www.luminous-landscape.com/tutorials/polarizers.shtml)
Re: Why they're Idiots: (*Pics): Canon Talk Forum: Digital Photography Review (http://forums.dpreview.com/forums/read.asp?forum=1010&message=14720859)
Polarizer - Camerapedia.org (http://www.camerapedia.org/wiki/Polarizer)

Hi Jack , II have an XH-A1, regarding polarizers I would like to know why when I look through my Hoya PL-CIR polarizer do I see the view change colour so dramatically from brown to blue when I rotate it? I'm looking square on with white 2m yrds behind filter. Would a better quality B+H polarizer be better (less colour shift) or even better a B+W linear polarizer? I want to use the polarizer to enhance colour , reflection removal is less important.
Any advice appreciated
G

Haven't used my Hoya Moose Circular Polarizor for over a year.

I shoot aircraft and sometimes it's great for stationary shots but outdoors in the sun, the instant you pan you lose the polarised effect.

Cheers.

It may be worth mentioning that both a circular pola and a linear pola will work on any camcorder, but the circular represents no advantage and is more expensive, so there is no reason to buy that one unless you also plan to use it on an SLR.

And since this also causes confusion: the designations refer to the design of the polarizing element and not to the external shape of the filter. You can have a round linear pola, or a rectangular circular pola!

Hi Jack , II have an XH-A1, regarding polarizers I would like to know why when I look through my Hoya PL-CIR polarizer do I see the view change colour so dramatically from brown to blue when I rotate it? I'm looking square on with white 2m yrds behind filter. Would a better quality B+H polarizer be better (less colour shift) or even better a B+W linear polarizer? I want to use the polarizer to enhance colour , reflection removal is less important.
Any advice appreciated
G
I'm not sure the colors actually change... have you check this in the video on a monitor?

The polarizer will darken the sky and/or the image in general. The amount depends on the on the angle of light to the lens. For example the effect is strongest when the sun is at right angle to the shooting direction of the camera.

Better quality polarizers may have additonal coatings that limit other kinds of reflections. More expensive filters can also be made form a better quality (read, more expensive to make) glass. The B+W filters (at lest the ones I've bought) have a copper/brass ring and not aluminum, so the theory is (and I have found it to be true), the filter does not "freeze" onto the lens, making it difficult to remove.

Also, there are different thicknesses of metal ring on the filters, and sometimes this can make a difference in price.

I believe some polarizers are also more effective than others, but I don't know details.

But in the case of colors changing, I think it might just be a darkening of the picture that appears to be a color change in the camera's viewfinder.

Can I butt in and ask - possibly - a stupid question?
What actually is the difference between circular and linear polorisers? I've never actually used one in video, I have a very old one on my (film) SLR stills camera but it doesn't say if it circular or linear, just looking via the viewfinder/LCD screen on the G1 it seems to have the polorising effect OK

Can I butt in and ask - possibly - a stupid question?
What actually is the difference between circular and linear polorisers? I've never actually used one in video, I have a very old one on my (film) SLR stills camera but it doesn't say if it circular or linear, just looking via the viewfinder/LCD screen on the G1 it seems to have the polorising effect OK
The differences in the two are explained here:
Polarizer - Camerapedia.org (http://www.camerapedia.org/wiki/Polarizer)

Just for the record:
a linear filter on a A1 will give the same results as a circular on a DSLR?