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These filters are very useful for controlling image brightness when viewing bright targets such as the Moon, as the Moon can be so bright in a telescope that actually dimming the image can allow you to see more detail on the Lunar surface!

This filter set comprises two 1.25" filters: 1x 25% neutral density and 1x No 47 violet. The filters are supplied in plastic storage cases. The filters can be combined both with each other and with other 1.25" colour filters.

Both filters are made of top quality optical glass and are mounted in black anodised aluminium holders.

Specification

ND25 Neutral density filter to fit 1.25" filter threads (25% transmission). The 25% neutral density filter reduces transmission evenly accross the spectrum. The ND25 is a great filter for glare reduction and is very useful when observing the Moon and can be useful for splitting close double stars and observing bright planets (eg. Venus).

No 47 dark blue/violet colour filter to fit 1.25" filter threads (10% transmission. Very Uueful for enhancing detail on the Moon and one of the best filters to enhance views of Venus, darkening upper atmosphere cloud detail. A great filter to enhance the polar caps of Mars and cloud belt detail on Jupiter and Saturn. It pulls out festoon, barge and rill detail in Jupiter's cloud belts and Great Red Spot and will help pick out elusive detail in Saturn's cloud belts and polar regions as well as improve contrast in the rings. Can also be used to improve separation of bright double stars.

Note that the appearance of the target and the detail improvement shown by a particular filter varies with the conditions - experimentation is the key.