Articles

Polarizing filters test

10. Fomei Digital CPL 67 mm

	Fomei Digital CPL 67 mm	Price: in a set

There’s not much information on Fomei filters. The set of a UV, an ND4 and a circular polarizer of 67 mm diameter can be purchased for less than 100 PLN, which suggests that these products are aimed at the amateur market. Unfortunately, the widest available diameter of the filters is 67 mm, so in order to test the Fomei polarizer we needed to use a reduction ring, additionally, to place the filter in the overall ranking, we took the arithmetic mean of other filters’ vignetting for it.

Results of the test

Transmission and extinction coefficient
- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Red color extinction coefficient: 3.72E-2 - Score: 0.5/4 Green color extinction coefficient: 2.85E-2 - Score: 0.5/4 Blue color extinction coefficient: 9.23E-2 - Score: 0/4 Mean transmission of the whole spectrum: 43.38% - Score: 3/3 Score:	4/15
Flares
Without filter With filter Score:	3/7.5
Scattering
Luminance: 22.8 Score:	4.71/5
Vignetting
Edge darkening: Arithmetic mean of all competitors Score:	3.49/5
Homogeneity
Without reservation Score:	5/5
Final score
Overall ranking: 18th place Econo-ranking:not included 20.2/37.5 pts (53.9 %) -

Usage

The ring turns smoothly with an appropriate resistance, cleaning wasn’t troublesome. The filter is well-made, it’s impossible to find faults with its construction. We get a cap in the kit.

Summary

18th place in the overall ranking (20.2/37)
One should notice that the accepted vignetting grade by no means lowers the filter’s position in the ranking. In case of the highest grade in this category its place in the ranking wouldn’t change. The transmission curve is flat except for blue and violet colors, which are partially cut off. The extinction coefficient of around 1/100 is poor for modern technology. We observe the transmission of blue and red colors at the level of 5-10%, which may cause extinguishing of reflections on photographed subject and turning them purple. C1 and C2 graphs indicate that we’re dealing with a quarter-wave plate of zeroth order designed for the middle of visible spectrum. Very good transmission allows shortening exposure, too bad the producer didn’t think of antireflection coatings. It’s hard to demand more of a filter sold in a kit of three, for less than 100 PLN.

Filter for tests was lent by Medikon Poland.