What's the difference between different circular polarizers?

[RockDawg]

I am looking to buy a circular polarizer for my Nikon 18-70 lens and I'm a bit confused on the different types. Take the 67mm Hoya for example. at Adorama they list:

Hoya 67mm Circular Polarizer Glass Filter
Hoya 67mm Circular Polarizer Multi Coated Glass Filter
Hoya 67mm Extra Thin Circular Polarizer Super Multi Coated Glass Filter
Hoya 67mm DMC PRO1 Digital Circular Polarizer Glass Filter

What is the real world difference betrween them (I've read Hoya's site, but the technical mumbo jumbo doesn't mean much to me)? Also, how do you know if you need a "thin" version. They say it helps avoid vignetting on wide angle lenses, but how wide a lens befire you need one?

 

[TamiyaGuy]

The multi-coated lenses help to reduce flare on metallic objects. I think the example I saw was on a 10 pence piece (of course, that was a bit of marketing skills ). The extra thin one probably does help a bit with very wide-angle lenses, but it's difficult to tell just how wide you can go before vignetting occurs. I guess the only real way to find out is by trying one yourself.

As for the PRO-1 filter, it basically means that the glass is of a higher quality. Whenever you put a piece of glass on top of another 9-18 pieces of glass (i.e. your lens), it will degrade the quality, no question. The PRO-1 series, however, don't degrade the image quality as much, at the cost of your hard-earned cash

I, personally, don't own a polariser, so I can't really tell you the real world difference, but the only way to make absolutely sure is to try each one out for yourself, then make a decision.

 

[Big Mike]

The first part is easy...some are multi-coated or have some special coating to help reduce flare etc. They are more expensive than filters without fancy coatings. A thin filter will usually be more expensive. Some wide angle lenses can vignette with thick filters, so that's where you would need a thin filter.

There is of course the quality of glass to consider and the most expensive filters will usually have top quality glass.

As with anything else, the brand name will make a difference.

 

[christopher walrath]

Generally more than two filters stacked on a 28mm (35mm film format) lens will begin to cause vignetting. A thin filter would only help if it meant the threads were shallower. But then all of the filters would have to be the same and you might be able to get away with three, max.

 

[RockDawg]

So after the coatings it's pretty much better glass that is all that seperates them? Are there any real world or measurable differences between the mid and high end if they both have a coating?

Also, am I correct in assuming that if you have larger diameter filters and use a step up ring that would help minimize vigentting that could result from stacking?

 

[RockDawg]

Generally more than two filters stacked on a 28mm (35mm film format) lens will begin to cause vignetting. A thin filter would only help if it meant the threads were shallower. But then all of the filters would have to be the same and you might be able to get away with three, max.

Thanks. I figured there were no hard and fast rules governing this, but I appreciate the general guideline of two filters on a 28mm (~18mm on my D80). That's exactly the type of info I was looking for.

 

[Garbz]

As for the PRO-1 filter, it basically means that the glass is of a higher quality. Whenever you put a piece of glass on top of another 9-18 pieces of glass (i.e. your lens), it will degrade the quality, no question. The PRO-1 series, however, don't degrade the image quality as much, at the cost of your hard-earned cash

Quick call the doctor. This man is a victim if marketing!

The first three is easy. Hoya offer filters with varying levels of anti-reflective coatings on them. The filter in the list I would choose is the 3rd one down the SHMC extra thin polariser.

That last one is marketing BS. Or do you really think Hoya has made a filter that some how works magically better for our digital cameras? What makes our digital cameras different from film cameras on that side of the lens? Nothing. The light doesn't care if it'll end up on the film or on a digital sensor.

"Digital Multi Coating" Is a method invented by hoya to separate fools from their money. I have found no visible difference in the performance of my lenses with and without SHMC filters even when nitpicking at 100%. I've posted results of the tests on this forum previously too. But by all means if you believe that you have a digital sensor therefore you need thinner glass on the filter then the Pro1D filters are the ones for you.

 

[TamiyaGuy]

Quick call the doctor. This man is a victim if marketing!

That last one is marketing BS. Or do you really think Hoya has made a filter that some how works magically better for our digital cameras? What makes our digital cameras different from film cameras on that side of the lens? Nothing. The light doesn't care if it'll end up on the film or on a digital sensor.

I guess it is a lot of marketing crap, but the Pro-1 series does definitely have better quality glass in their filters. Either that, or they're adding £40-odd to the price for nothing :meh:. Of course, whether or not the difference would actually be distinguishable from the "bad" polarisers, I have no idea. However, I do agree that a specially-designed digital filter is absolute rubbish. It's light, what more can I say?

 

[Meysha]

That last one is marketing BS. Or do you really think Hoya has made a filter that some how works magically better for our digital cameras? What makes our digital cameras different from film cameras on that side of the lens? Nothing. The light doesn't care if it'll end up on the film or on a digital sensor.

"Digital Multi Coating" Is a method invented by hoya to separate fools from their money. I have found no visible difference in the performance of my lenses with and without SHMC filters even when nitpicking at 100%. I've posted results of the tests on this forum previously too. But by all means if you believe that you have a digital sensor therefore you need thinner glass on the filter then the Pro1D filters are the ones for you.

I think it's marketing hype too... but, here's a reason I've heard people throw around before and I'm interested in your opinions on it.
I've 'heard' that the digital filters have an extra anti-reflectiveness (can't think right now) built in to stop the light actually reflecting off the sensor and back.

But isn't film shiny too?

 

[Battou]

I think it's marketing hype too... but, here's a reason I've heard people throw around before and I'm interested in your opinions on it.
I've 'heard' that the digital filters have an extra anti-reflectiveness (can't think right now) built in to stop the light actually reflecting off the sensor and back.

But isn't film shiny too?

Film has a mat appearence to it on side that gets exposed, but I have heard no such thing about digital filters being any different than film filters.

 

[Garbz]

Of course, whether or not the difference would actually be distinguishable from the "bad" polarisers, I have no idea. However, I do agree that a specially-designed digital filter is absolute rubbish. It's light, what more can I say?

Oh it is, the first one is definitely a bad polariser. I know I have one here. But I have UV filters in the other categories, one is a SHMC (my preference) and one Pro1 which was on a lens I bought second hand.

They both look the same, weight about the same, perform the same, and in both cases are 100% unidentifiable when used on sharp lenses when they are not causing ghosting, and both still cause the same kind of ghosting (single additional purple image of light source with no loss of contrast in the rest of the image).

I'm not sure where you see this better quality glass, but I hope to god you're not relying on what's written on the package. Afterall the Hoya SHMC was top quality glass before digital cameras came out, why should it suddenly not be? Can you provide me with any evidence to the contrary?

 

[TamiyaGuy]

Very good point, Garbz, Hoya is one of the best filter makers out there. But I can't help but think that there must be some difference between the SHMC ("bad"), and PRO-1 ("good") polarisers. Otherwise you're paying, what, 2 times more money for nothing??? That's bordering on fraud.

I do agree with both you and Battou, I would get the SHMC as well, and the real-life difference would probably be indistinguishable, but there has to be some difference, no matter how small...

 

[Garbz]

Wow bad timing. Just came back to edit and say I found one difference. Micrometre shows the ring of the Pro1D filter to be about .6mm shorter... err lower profile some may say.

Also you put a lot of faith in companies. I am sure you are actually paying twice the price for absolutely nothing better. The website feeds the line that DMC "greatly reduce the appearance of lens flare and ghosting caused by reflections" Pity they say the exact same thing about the SHMC filters.

In fact other than saying the glass is black on the edges to reduce internal reflections which I guess is better than having a glass in a black frame which it is now ??? (wait what? internal reflections?), their website makes no claims about the glass being any different. Though they make some radical claims about the ring. Somehow the matt black finish on the DMC ring is better than the matt black finish on the ring of every other of their products.

Oh and if the alarm bells weren't ringing before, the SHMC part of the website goes into massive details, how, why, shows graphs of it's effective wavelengths which would appear right given the colour of the ghosting image I get. But the part of the site that mentions DMC just puts that one marketing line above along with a fancy logo which they probably paid some guy 40 quid to design.

 

[tirediron]

A couple of observations, first 'thin' polarizers generally "gain" their thiness at the expense of having no female threads on the outside, therefore if you do have more than one filter stacked, a thin polarizer (or any other thin filter) will have to be the last one.

As far as stacking, if I put my thin polarize on my 17-70 (which always has a UV) I start to get vignetting at about 20mm; if I use a regular polarizer, more like 24-25mm

Lastly, I agree, there is a lot of hype and marketing gibberesh, BUT with most reputable companies, there is always some "you get what you pay for". My cheap Hoya CP produces markedly different results from my top-end B+W, and IMHO, is well worth the extra cost.

I'd suggest taking your camera into the store, and try each filter; expose a half-dozen frames, go home, look at them and see what you like better.

 

[TamiyaGuy]

Wow bad timing. Just came back to edit and say I found one difference. Micrometre shows the ring of the Pro1D filter to be about .6mm shorter... err lower profile some may say.

Also you put a lot of faith in companies. I am sure you are actually paying twice the price for absolutely nothing better. The website feeds the line that DMC "greatly reduce the appearance of lens flare and ghosting caused by reflections" Pity they say the exact same thing about the SHMC filters.

In fact other than saying the glass is black on the edges to reduce internal reflections which I guess is better than having a glass in a black frame which it is now ??? (wait what? internal reflections?), their website makes no claims about the glass being any different. Though they make some radical claims about the ring. Somehow the matt black finish on the DMC ring is better than the matt black finish on the ring of every other of their products.

Oh and if the alarm bells weren't ringing before, the SHMC part of the website goes into massive details, how, why, shows graphs of it's effective wavelengths which would appear right given the colour of the ghosting image I get. But the part of the site that mentions DMC just puts that one marketing line above along with a fancy logo which they probably paid some guy 40 quid to design.

Well, Garbz, you've made a fantastic point, you've explained it, and you have really converted me! :hail::hail:. Good to have a nice debate every now and then, but no hard feelings, eh? Weird about the description of the PRO-1. I mean, surely all the emphasis of the website would be on the more expensive PRO-1 series. It's how I would design a site, anyway... And yes, I do put quite a bit of my faith in the Hoya's marketing, but then again I don't have the faintest clue about polarisers and the tiny little details between each one. They block certain light, that's all I need to know . I try to do my homework, but I sometimes just have to rely on what others tell me.

Thanks for explaining, Garbz.