That works great for the outer elements. It's harder to see damage on the
middle elements without a light source like a flashlight.
Skip
>
>Subject: [OM] Re: Finding Fungus For Fun
> From: "Joseph Ascione" <jascione@xxxxxxxx>
> Date: Mon, 26 Apr 2004 11:08:44 -0400
> To: <olympus@xxxxxxxxxx>
>
>
>I usually hold the lens up to a light and look at it with a 10x jewelers
>loop at both ends. I can then see early signs of fungus.
>
>-----Original Message-----
>From: Walt Wayman [mailto:hiwayman@xxxxxxx]
>Sent: Monday, April 26, 2004 10:06 AM
>To: Oly List
>Subject: [OM] Finding Fungus For Fun
>
>I received an off-list e-mail inquiring about the possibility of using
>the little Hakuba slide viewer that I posted about last week as a light
>source for the inspection of lenses for fungus, dust, and so forth.
>With only moderate verbosity, I expressed my opinion, then proceeded to
>opine further about what I considered to be the proper way to check the
>innards of a lens.
>
>Then I got to wondering if my advice was as good as I thought it was
>when I wrote it. Since we're all, at least those who remain true-blue
>OM users, now in a position of dealing almost exclusively with used
>gear, often bought sight-unseen based on a description by a total
>stranger in a faraway place who may be either ignorant or dishonest, or
>both, we need to know how to inspect the gear properly. It seems we're
>hearing more and more about problems with lenses bought over the
>internet from some in our group.
>
>Anyway, this is what I wrote, and if anyone has any disagreement, any
>correction, or a better modus operandi, I think it would benefit us all
>to hear about it. I can't always be perfect, you know, and do
>occasionally learn a thing or two here.
>
>"The little Hakuba slide viewer is definitely NOT the tool you're
>looking for to inspect lenses. The best way to spot nasties inside a
>lens is by shining a plain old flashlight through it, from each end,
>while moving the light and the lens around. Like the focused beam of
>light from a slide projector shows the dust floating in the air, all of
>which was invisible in the diffused room light, the focused beam of the
>flashlight sharply reveals the crap inside a lens.
>
>"As an experiment this morning, I used both the slide viewer and a
>two-cell Mag-Lite to look at the only lens I have that I know has an
>internal problem, a 65-200/4 Zuiko with the all-too-common bad element
>toward the back. With the diffuse light from the slide viewer, had I
>not known about the bad element, chances are better than good that I
>would have overlooked it. With the hard light from the Mag-Lite, the
>frosting of the element was immediately obvious, as
>was every speck of dust inside the lens.
>
>"In fact, using a flashlight to look inside a lens, particularly a zoom
>lens, can be a scary experience. It puts me in mind of a line from an
>old Rod Stewart song: "The morning sun, when it's in your face, really
>shows your age." Almost every lens has at least one or two specks of
>dust inside, and a hard light source, just like a projector in a dark
>room or the sun on Maggie May's face, shows things that soft, diffuse
>light won't."
>
>Walt, standing by for correction
>
>--
>Everybody thinks they have a sense
>of humor -- even people who don't.
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