Winds NNE at 9 mph (14.5 kph). The overnight low will be 41 Â°F (5.0 Â°C).Cloudy with a high of 62 Â°F (16.7 Â°C). Winds variable at 9 to 11 mph (14.5 to 17.7 kph). 50%58Â°47Â°Rain today with a high of 58 Â°F (14.4 Â°C) and a low of 47 Â°F (8.3 Â°C). There is a 50% chance of precipitation.
The amount of filtration of the x-ray beam is specified by and based on the voltage potential (keV) used to produce the beam. The thickness of filter materials is dependent on atomic numbers, kilovoltage settings, and the desired filtration factor.
The amount of filtering depends on which filter you get. They are both used for different things. Use a polarizing filter when photographing water, as it will help to cut down the reflections from the sun. Use a graduated ND filter if photographing both the sky and a darker piece of land in the one shot. Although these days, I recommend instead of using a graduated filter, you instead photograph in HDR which will give you all the range a graduated filter tries to restore.