Archived from groups: rec.photo.digital (
More info?)
"Michael A. Covington" <look@www.covingtoninnovations.com.for.address> wrote
in message news:41b934af$1@mustang.speedfactory.net...
> "richard schumacher" <no-spam@thank-you.com> wrote in message
> news:no-spam-53745D.22324309122004@news.isp.giganews.com...
> > In article <cpakcq$86q$1@news.Stanford.EDU>,
> > "Tom Nakashima" <tom@slac.stanford.edu> wrote:
> >
> >> Most all lenses are coated today. But I'll have to agree with Angela
and
> >> use a protection filter and save the lens. Not sure if you've ever got
> >> grits of fine sand on a lens? Try wiping/blowing that off a
multi-coated
> >> lens, I don't care what soft chamois you have, it will scratch the
> >> coating,
> >> I've seen it under a microscope.
> >
> > Why not do it the way astronomers clean eyepieces and mirrors? They'd
> > kill anyone who would take a chamois to an optical surface. One common
> > method is to use reagent grade alcohol and new cotton balls, floating
> > off the dirt.
>
> That's the way to clean an aluminized front-surface mirror. Coated lenses
> are much tougher. With coated eyepieces, I have no qualms about using
> Kimwipes or a microfiber cloth *gently*, with a Windex-like or
alcohol-based
> solvent. Chamois is not the right material for cleaning lenses.
>
> BTW, a good bit of what passes for damage to coatings is actually just
thin
> streaks of oil or the like, which can be removed.
>
>
> --
> Clear skies,
>
> Michael A. Covington
> Author, Astrophotography for the Amateur
> www.covingtoninnovations.com/astromenu.html
>
Oh really? You didn't mention the alcohol, is it Methanol, Propanol,
Ethanol that you use on your aluminized mirrored telescope lenses? The
Stanford Linear Accelerator Center just built a telescope using aluminized
mirrors. They used filtered nitrogen in a cleaning room to remove dust from
the mirrors.
The coating on a camera lens isn't as tough as you think it is. The coating
can be scratch, I don't care how soft your lens tissue is. It's not a good
thing when the light reflects on these scratches, you can run your own test.
The only way to repair these scratches is to have the coating stripped and
reapplied and you're talking bucks, probably better off buying a new lens.
That's why many of the die-hard phographers prefer no coating, so you could
actually clean the lens. Uncoated Nikkor lenses are still a favorite with
some professionals.
When I purchased my Olympus C8080, the first thing I did when I opened the
package is install the UV filter, it's never been off.
fwiw,
-tom