TS Optics Grey (Neutral Density) Filter ND 09 - 12,5% Transmission

Reduces glare without colouring

Neutral Density filters are used to reduce glare on bright objects, thus improving observing comfort and increasing contrast.

The ND 09 is a dark grey filter. We recommend this filter for telescopes from about 135mm aperture and in cases where you desire a stronger reduction in image brightness (full moon, even with 90mm aperture).

Applications

Grey filters can be used for planet observing, solar observing (only in combination with a true solar filter!) and for nature observing. The function is similar to regular sunglasses - the image brightness is reduced, meaning less strain for your eyes. The filter can be used visually and photographically. A ND filter is also helpful for observing binary stars by reducing the glare of the brighter component.

The grey filters have filter threads on both sides. This allows you to stack several filters, combining their effect. For example two grey filters stacked will resemble one stronger grey filter. A grey filter and a colour filter will resemble a colour filter in the same colour but darker.

Adaptation

The filters are simply screwed into the 1.25" filter thread of the eyepiece or camera adaptation.

Transmission

The smaller the percentage of light transmission, the stronger the filter is. For example a 25% filter will allow 1/4 of the light to pass through, while the rest will be blocked. A 12.5% filter will transmit only 1/8 of the light.

Delivery contents

• 1.25" Grey (Neutral Density) Filter
  
• Protective box (plastic)