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Photography Forums => Technical Questions on Photography and Optics => Topic started by: dppollet on May 10, 2009, 12:25:44 PM



Title: The Cost vs. Performance Dilemma of Choosing a Circular Polarizing Filter
Post by: dppollet on May 10, 2009, 12:25:44 PM
I would like to know some of the technical reasons behind the broad range of prices corresponding to a given size of circular polarizing filter, especially for different models from the same manufacturer.  Other than the occasional appearance of a filter factor or a general reflectance curve, there is a distinct lack of technical data on filter performance. 

For example, Hoya presents reflectance curve data for their HMC and Super HMC polarizing filters.  However, they do not provide any similar data for their Standard or Pro 1D circular polarizing filters. 

A similar situation is encountered with Tiffen circular polarizing filters where they present a reflectance curve for their digital HT filters.  However, no data is presented for their standard circular polarizing filter.  Alternatively, B+W only provides identical filter factors for their standard and multilayered filters. 

Although I suspect that there are differences in the toughness and hardness of the coatings in addition to robustness of the substrate, there is no information that allows the user to decide which manufacturer and model best suits his needs and application.  This presents a real dilemma because the more expensive candidates are often more than twice the price of the standard models. 

How is one to decide on which filter to buy given the lack of information?


Title: Re: The Cost vs. Performance Dilemma of Choosing a Circular Polarizing Filter
Post by: KeithB on May 11, 2009, 09:54:51 AM
You depend on someone like Bob to bite the bullet and buy some:
http://www.bobatkins.com/photography/technical/polarizers.html
http://www.bobatkins.com/photography/tutorials/digital_filters.html

Or if you are shooting in museums and want as little light loss as possible:
http://www.kenrockwell.com/hoya/hd-filters.htm


Title: Re: The Cost vs. Performance Dilemma of Choosing a Circular Polarizing Filter
Post by: Bob Atkins on May 11, 2009, 07:39:53 PM
The differences between the major brands (Hoya, Tiffen, B+W, Heliopan) is mainly in terms of mechanical construction and coating rather than polarization efficiency.

You pay more for multicoating, more for brass vs. aluminum mounts and more for fullt edge sealed filters.

I'd go for a multicoated Hoya filter as best value. They are available in most sizes including the common 58mm (http://www.amazon.com/exec/obidos/ASIN/B00009R996/bobatkinsphotogr) and 77mm (http://www.amazon.com/exec/obidos/ASIN/B00009R9E2/bobatkinsphotogr)

Their "Pro" series digital filters cost a lot more and don't really perform any better. They may have extra coatings and blackened filter rings, but most of the time that won't make any practical difference.


Title: Re: The Cost vs. Performance Dilemma of Choosing a Circular Polarizing Filter
Post by: KeithB on May 12, 2009, 12:38:44 PM
Bob:
Have you checked out the Hoya HD?  Ken Rockwell reports (in the link above):
"More importantly, the new HD polarizing filters use magic polarizing material that loses less light. Most polarizers lose two stops of light. I measured this one, and it loses only 1 and 1/6 stop (one and one-sixth of a stop) of light. This means sharper photos at lower ISOs than using regular polarizers, about one full stop better."

Of course, when I am using a polarizer I *like* having the extra stop of neutral density.