MECO Optical 37MM MC-CPL Filter - Multi-coated, 99.8% Polarizing Coefficient, Ultra Slim, Aluminum Frame, Optical Glass Circular Polarizer Filter

I have both the 37mm and the 58mm both give the exact same results and below are the details of the 58mmI think the best way to describe a filter is to compare it with other productsI tested a 58mm TIFEEN (used adapter)a 52 mm ZEIKOSand the 58mm MECO (used adapter)the first picture shows the colour differences of the filter glass and coatingsThe Tiffen has a blueish hue, the Zeikos and Meco a brownish tintAll pics were taken on a tripod using a Nikon D90I also added the histogram on top of each pictureI took a set in “auto” mode and a set at ISO-200, f5.6 1/125Here are my results in auto modeTIFFEN, ISO-280 f5.6 1/125ZEIKOS, ISO-200 f5.6 1/125MECO, ISO-320 f5.6, 1/125If I would compare the picture quality of each filter:TIFFEN, sharp, 100% polarization effect, colours are flat and some loss of detail in colour dynamicsZEIKOS, some fussiness, 70% polarization, colours are flat and some loss of detail and colour dynamicsIn fact the histogram of the Tiffen and the Zeikos are almost identical although the Zeikos does not do a very good job on the polarization and the picture is fairly fuzzyMECO, sharp, 95% polarization effect, colours are BRILLIANT and this gives a WOW factorMaybe a tad softer compared to the TIFFEN but what a histogram!!!Here are the details of the histogramTIFFEN: Mean=75.53 , Std Dev= 57.28 Median=56MECO: Mean=89.58 , Std Dev= 64.71 Median=71Why did I not give the figures of the Zeikos?The Zeikos Polarization factor was very poor thus of course it would have higher level of colours in the water surfaceLets take a look at the filter thickness (first number includes the thread)TIFFEN 7.72mm 5.89mmZEIKOS 9.64mm 7.56mmMECO 7.35mm 5.38mmThe filter coating test:TIFFEN slightly coated but still gives some reflectionZEIKOS not coated (although the advertisement makes you believe it is)MECO great multi-coating with virtually no reflectionThe MECO comes in a very nice metal box and the box states: DESIGNED in Chicago IllinoisIndeed, there is a difference in-between “designed” and “made in”This product is not made in the USA, is very popular in India but it's a quality Chinese made productI do not want to scare you, remember your iPhone is also made in ChinaWithout a doubt this is a well build quality product at a fraction of the priceWill I recommend or buy one again? Without hesitation the answer would be YES

Multi-coated with a 99.8% light transmittance? This is quality. Compared to a lower cost Hoya on the same lens, the polarization is just as good. It is about two f-stops faster. The color is slightly warm (or, the Hoya is slightly cold). AR coating is great. This is a great product and great price.