> My thought would be to use an LED under the glass without fibre or
> lens, so it is illuminating the area the fibre is looking at without=20
> having
> fibre alignment issues between the sensor fibre and the illumination
> fibre. The sensor will still need some form of spot sensing focusing to
> get the required resolution, whether this is done by fibre or lens will
> be up to the implementation

It's a definite improvement if the fibre isn't right to the end of the=20
sheath,
otherwise scattered light from wider angles (ie fuzzy resolution) enters
the end or side of the fibre. That goes hand in hand with the sensitivity
of the amplifier

Joe=20

--=20
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