FILTERS

F. 1 Filter, neutral, rectangular

(I observed an eclipse of the Sun through a wad of five of these, by looking at the Sun reflected in a bowl of water. The five layers of filter gave the image a deep red coloration.)

£6.00

F. 2 Filter, neutral, circular

This is a circle of glass, 60mm in diameter and 5mm thick. It is neutral density and is a dark grey.

£6.00

SAFETY: NEVER observe the Sun directly through these, or any other, filter - you may lose your eyesight.
The coloured filter may remove the bright VISIBLE light, but not the dangerous radiation.
Also, of course, the filter might fragment if it were used in a telescope.
Just don’t use them for Sun observations – there are other methods.

F. 3 Filter, orange, circular

This is a disc of orange glass 33mm diameter and 1 ½ mm thick.

£2.00

F. 4 Filter wheel unit, heavy, brass

Inside this 1 ½” thick plate is a large brass disc, which carries the coloured filters.
By turning one of a pair of control knobs, this brass filter wheel can be made to rotate, to put different filter combinations in front of a large eyepiece built into the housing. If this assembly were part of a telescope the view could be made red, yellow, clear and polarizing. By turning the other ('Density') knob a second polarizing filter rotates in front of the first, to vary the brightness of that image. Please note that the polarizing filters are in poor condition, but could easily be replaced.

The large eyepiece is a Plossl with a fine-focussing ring, and you get it free with the rest of the item. Don’t say we never give you anything! Total weight 5 lb.

£75.00

F. 5 Stepper rings for camera filters

These are brand new black anodised rings with different threads on each end. The sizes available are: C49/52, C49/55, C49/58, C49/62, C52/52, C52/55, C52/58, C52/62, C55/55, C55/58, C55/62, C58/58, C58/62 and C62/62.

£5.00 each