Date: 9/8/20 9:46 am From: Rebecca Hartman <rhartman...> Subject: [obol] Re: Another optics related question
I have that lens-cleaning brush and I highly recommend it. Got it last
year when I finally invested in my first pair of quality bins. A lens brush
for dust is essential over here on the east side. The other end of that
brush/pen has a sort of soft rubber polishing cup, but mostly I just use a
lens cloth. You can wash lens cloths, according to my eye doc, but I think
repeated washing degrades them. Physically, that is.
On Tue, Sep 8, 2020 at 9:29 AM Nagi Aboulenein <nagi.aboulenein...>
> Hi Lars,
> Yes, lens coating can be very sensitive to careless cleaning and once gone
> or scratched, the coating can’t be restored. Years, ago, after destroying
> the anti-glare coating on some of my eyeglasses by cleaning them too
> vigorously with whatever piece of cloth was nearest, I’ve learned my lesson
> and am now more careful.
> My guess for “microcloth” would be microfiber cloth. Either the little
> eyeglass cleaning cloths (generally a very fine weave) or the coarser weave
> (but still very soft) larger microfiber cloths would qualify, I would
> think. The common aspect of all of them is that they are very soft and not
> scratchy. When using the larger clothes with the coarser weave I would
> recommend at least shaking them for a few seconds to make sure that any
> dust/sand/debris particles are gone. Cotton cloths (e.g., t-shirts) can
> have some hard fibers in them, but in a pinch, will do if used gently.
> In theory the best approach is to use a lens-cleaning brush (compact, fits
> in a pocket like a pen) or blower to first get any sand/dust particles off
> the lens (see attached photo of blower), then use a lens cleaning cloth as
> above to gently wipe off. This is for dry cleaning of the lens. For other
> situations (e.g., salt water spray when at the beach, etc,) I wipe the lens
> with one or two alcohol-soaked lens cleaning wipe (e.g., Walmart carries
> excellent Zeiss lens-cleaning wipes at their optics departments).
> Tissues, paper towels, TP all have little, often invisible, pieces of hard
> wood debris in them that don’t hurt our noses (or other parts), but that
> definitely are going to hurt your lens coatings.
> On Sep 8, 2020, 08:48 -0700, larspernorgren <larspernorgren...>,
> Just what is a "microcloth"? Should I make an effort to use them over
> t-shirts, toilet paper, paper towels? In high school our physics teacher
> explained how the coatings on lenses worked, and how easily these delicate
> layers could be damaged by careless wiping. Everytime l get a new set of
> prescription glasses they come with a case and cleaning cloth. Every time l
> lose those glasses l keep the case and cloth. I have also acquired small
> pieces of textile targeted for lens care at symposia, complete with the
> event's logo.
> The various cloths in my possession are highly variable. Some are
> hard and smooth and make me think they might scratch the coating directly,
> or fail to absorb dust particles and blemish the coating by a sort of
> secondary action. Some of these cloths are very thick, pleasing to my
> fingertips. I fantasize such absorb the dust and lovingly cleanse the
> sullied lense. Even the best of textiles must eventually get clogged. Can
> they be cleaned, and how?
> Is it advisable to store clean cloths in a ziploc bag or other
> tightly sealed device? I always keep eye glasses in the glove box, and
> accompanying cloths in the glasses' case I got at time of purchase.
> Typically, after a drive from Fields to Roaring Springs my glove box has
> dust in it. So does the inside of most of the eyeglass cases. Isn't it
> probably worse to use a "micrcloth" drenched in road dust than an
> immaculate, disposable paper tissue? Will vigorous shaking render the dusty
> cloth safe? How about using drinking water for a field cleaning?
> Sent from my Verizon, Samsung Galaxy smartphone
Dr. Rebecca Hartman
Associate Professor of History
Eastern Oregon University
*The universe is full of magical things patiently waiting for our wits to
grow sharper.”*― Eden Phillpotts