Polarizing filters test
19. Hoya Pro1 Digital MC PL-C 72 mm
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One of the most famous producers of photographic filters, ocular lenses, contact lenses and other optical components. It was established in Japan in 1941. The fact that it absorbed Pentax at the end of March, 2008, may prove its power. In UV filters test Hoya had three first places in the overall ranking and four in the econo-ranking. Now it’s time for circular polarizers, will Hoya be the dark horse again?
Results of the test
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Red color extinction coefficient: 9.68E-5 - Score: 4/4
Green color extinction coefficient: 1.51E-4 - Score: 3.5/4 Blue color extinction coefficient: 3.54E-3 - Score: 2/4 Mean transmission of the whole spectrum: 30.5% - Score: 1.1/3 Score:
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With filter Score:
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Luminance: 14.6
Score:
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| Edge darkening: 5.3% Score: |
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Visible streaks
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Usage
The ring turns smoothly with an appropriate resistance. Unfortunately, the antireflection coatings are delicate and scratch easily. |
Summary
7th place in the overall ranking (27.2/37.5)The transmission curve is quite flat nearly up to 700 nm, after that it increases in the range of red. The extinction coefficient of about 1-1.5/10000 is excellent for a foil polarizer. C1 and C2 graphs indicate that we’re dealing with a quarter-wave plate of zeroth order designed for the middle of visible spectrum. The mean transmission is not fantastic. Visible streaks don’t reflect well on the optical quality of used materials (or the production). The influence of such streaks on resolution requires separate tests. Ultimately, the filter placed 7th. It is due to a very good work of the polarizer and excellent level of scattering. We need to add, though, that optical homogeneity is graded using a scale to 5 with weight of 1, so it’s hard to draw conclusions of real consequences of such aberrations on the image. If they’re drastic, maybe we should increase weight of this grade. The second thing is that it’s impossible to evaluate durability of layers against abrading . You need to accept the place in the ranking with those two remarks.
Filters for tests were lent Cyfrowe.pl and Fotozakupy.pl
