Lasizas Stern Light

SteveIOW

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Have just purchased this low profile LED stern navigation light. Fitting instructions do not state the orientation, ie should the fixing screws IMG_3826.pngbe side by side or one above the other. Pretty sure only one way will give the required 135 degree horizontal beam.
Anyone know which way it should be fitted please?
 
It’d have to be vertical to make the correct angle.
Check the manual thoroughly as many LED fittings start blinking after a couple of years to indicate end of life and required replacement. This is intentional.
 
Have just purchased this low profile LED stern navigation light. Fitting instructions do not state the orientation, ie should the fixing screws be side by side or one above the other. Pretty sure only one way will give the required 135 degree horizontal beam.
Anyone know which way it should be fitted please?
ITYWF that the fixing screws should be top and bottom so that the elements of the Fresnel lens are horizontal to concentrate the light beam into a wide horizontal beam with little light escaping skywards or towards the water.
I'm a bit doubtful about it having good cut off angles at 135° but maybe it'll be ok.
 
The metal is the cut off, either side of the lenses which are recessed. The light is flat so the lenses are there to scatter light sideways and therefore need to be vertical.
 
. . . The light is flat so the lenses are there to scatter light sideways and therefore need to be vertical.

The point of fresnel lenses is specifically to not scatter light, but to concentrate the beam in a single direction. Typically used to focus light from a point source along a parallel beam, instead of continuing to splay out in all directions.

I believe the fresnel sections should run horizontal - i.e. be at the top and bottom of the fitted lamp (with screws also at its top and bottom), to focus the light around the horizontal and not waste it illuminating the sky or the sea, and that the inward angled section of the metal cover will form the required 135 degree angled cut-off.

You could check by connecting the lamp to a 12v battery, and along one axis the bean should should spread pretty evenly exactly 135 degrees only (and not visible at all beyond that), and along the other axis mainly focus around the centreline, but some scatter either side not critical.

Here's examples of other nav lights, clearly showing the fresnel sections running horizontally:
1767023565051.png
(above Osculati, below Lalizas)
1767023757223.png

The advert says it is Lalizas, but I notice this lamp is not listed on the Lalizas website, and that those navigation lights which are listed there each have a drawing showing how it is mounted.
 
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