Re: [Leica] Filters, again, very long.

[TEAShea@aol.com]

<< >What about things collecting in the micro-fiber and leaving scratches on
 >the glass? >>

Actually, it is not an issue of scratching the glass, but scratching the
coating.  Modern coatings are very hard, but older coatings were soft.  One of
the first coatings was magnesium fluoride which was so soft that its was quite
impractical for the outside of front and rear elements.

Microfiber cloth is poly - which is much harder than cotton.  The advantage of
micrfiber is that it is very absorbant and the fibers are so small in diameter
that any scratches are very small.  Additionally, the poly in the microfiber
cloths is not as hard as modern lens coatings - but should not be used on
older lenses with softer coatings.

Of course the biggest problem is that any dust on the lens surface is rubbed
into the coating by the cloth (cotton or microfiber).  Dust often contains
silica - which is very hard and sharp.  Silica is harder than even modern lens
coatings and will leave scratches.

Tom Shea