Review: Comparing Circular Polarizing Filters – Hoya HRT CIR-PL UV vs. Singh-Ray LB Warming CP

Hoya HRT CIR-PL UV filter

Hoya HRT CIR-PL UV filter

Singh-Ray LB Warming Circular Polarizing filter

Singh-Ray LB Warming Circular Polarizing filter

Comparing Circular Polarizers

I have two circular polarizing filters in my camera bag that seem to perform about the same…but do they? I did a simple test with my camera to find out. Here’s how they compare:

Manufacturer’s descriptions:

The Hoya HRT CIR-PL UV filter:

High-Rate Transparency Film
This filter uses a newly developed High-Rate Transparency film that passes more visible light through the filter while still filtering the same amount of polarized light. The HOYA HRT circular polarizer filter transmits as much as 25% more light through the polarizing film giving the photographer about 1/3 stop more light than a standard circular polarizer. This new polarizing film is also used in the latest HD LCD TVs.

UV Absorbing
The glass of the HOYA HRT filter also has UV absorbing properties making the HRT a combination UV/circular polarizing filter. The most common use for a circular polarizer filter is to darken bright blue skies in outdoor photography, but they also can reduce or eliminate reflections from non-metallic surfaces such as glass and water. By rotating the outer ring of the filter the change of effect can be seen by looking though the filter or through the viewfinder if it is mounted on a camera.

Hoya HRT CIR-PL UV box

The Singh-Ray LB Warming Polarizer filter:

LB: Lighter, Brighter.
Singh-Ray LB filters are 2/3 of a stop faster than comparable competitive filters, giving you greater creative flexibility without any sacrifice in performance or impact.

Most of today’s top outdoor photographers still consider a polarizer one of their most essential filters. While software can darken skies, it cannot replicate the drama and impact a high-quality polarizer can produce in the sky. And one of the most important reasons to use a polarizer – to control glare and restore detail, color and saturation to foliage and other reflective surfaces – is something no software can simulate.

Singh-Ray’s LB warming polarizer adds a subtle warming factor to our neutral polarizer, improving shadow detail and giving your images a little extra pop. And just like our neutral polarizer, it delivers unmatched optical resolution and color fidelity. Our LB warming polarizer also brings 2/3-stop more light to your viewfinder, making it easier to compose and focus accurately in early morning and late afternoon light.

Comparison images (click on each to get a larger view):

I took some comparison images within a few seconds of each other at exactly the same position and focal point. All were taken perpendicular to the sun for best effect of the polarization. All were taken with the white balance set to sunny.


Hoya HRT CP UV full low none

Hoya HRT CIR-PL UV at fullest polarization (left), lowest polarization (middle), and without filter (right).

The Singh-Ray LB Warming CP:

Singh Ray LB Warming CP full low none

Singh-Ray LB Warming CP at fullest polarization (left), lowest polarization (middle), and without filter (right).

Comparing the numbers in-camera:

The Hoya and the Singh-Ray both let the same amount of light pass through them at full polarization. Both full polarization images were at the same settings of 1/60s, f/5.0, ISO100, 18mm.

At lowest polarization, for both filters, the settings were f/6.3, ISO100, 18mm. The Hoya let in more light at lowest polarization by a factor of 2. The Hoya allowed a shutter speed of 1/125s where the Singh Ray allowed 1/100s.

Subjective comparison:

I like a warming polarizer for my images. Although I can get this in post-processing by changing the white balance, I like to leave my white balance set on sunny and use a warming polarizer as well. This gives me the look I am going for in most of my images.

The Hoya filter, while not a warming filter, has a UV effect that seems to give it a warming function. The color from the Hoya compared to the Singh-Ray is noticeably different at the lowest polarization. The Hoya gives a warming tone while the Singh-Ray does not.

The Hoya HRT CIR-PL UV filter lets in more light at the lowest polarization setting, and that is a plus for any photographer. We need the most light when the filter is at lowest polarization.

On the other end of things at the highest polarization, the Hoya and Singh-Ray filters are letting in the same amount of light.

Cost comparison:

The Hoya HRT CIR-PL UV filter is $39.95 for the 72mm size I used. By comparison, the Singh-Ray LB Warming Polarizer is $240.00 for the same 72mm size I used.

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