Flash reflector screen (difractive lens) scratches. Can affect somehow?

[klauscembike]

Hi! I recently purchased a second hand Metz 54 MZ3 electronic flash

unit. I didn't think too much on scratches and dirtness in the front

of the reflector lens. I cannot take the dirt away and the scratches

are easily seen, near the center of the "lenses". In the unit manual

says that "dirtness (don't know in which degree) on the reflector

screen can burn the material (dirtness?) or damage the reflector

screen"...

My question is: do those scratches affect to the light output? are

they dangerous somehow? or little dots scattered all over the

surface are not that dramatic?. Thanks a million in advance.

[hal_bissinger]

I wouldn't worry about the scratches as much as I would worry about the dirt. Dirt will cut down on the light output and the concern by Metz is that it will also absorb heat from the flash tube and possibly burn. If you can't clean it off I would see about having the lens replaced. Doesn't look like you got a great deal by the way unless you didn't pay very much.

[klauscembike]

Well, yes, it was a very good deal (30% off the regular price), but is always risky to buy a second hand flash... they're too delicate. Anyway I thought this dirt would go much more easily and anyway it should be replaceable... maybe i was too eager...