I just magnified the image by a factor of 4 or so - and the damage is quite
extensive. I'm fairly sure looking at it, it will make a difference to your
photos - and could even interfere with the cameras autofocuis system (if
any). You may have to use manual focus -will be interesting and useful to
see a shot or two from it - useful to others too in that we/they could then
judge whether or not to bother buying a lens in a similar condition in
future.
Allan
PS No trees were harmed in the sending of this message and a very large
number of electrons were asked their permission to be terribly
inconvenienced. (And threw a party for them afterwards for being really cool
about it).
Disrupting the unnatural balance that you, as a conscious human being and a
confused mass of energy, have created.
-Disturb the mind -
>From: "Allan Mee" <bigalsgroups@xxxxxxxxxxx>
>Reply-To: olympus@xxxxxxxxxx
>To: olympus@xxxxxxxxxx
>Subject: [OM] Re: ( OM) Photographs of lens damage
>Date: Sat, 04 Nov 2006 13:44:46 +0000
>
>
>Take test shots (at all apertures, both in and out of focus) to assess the
>effect of the damage to the lens - you might be lucky and merely get a bit
>of a light 'mist' effect which can be dealt with using appropriate
>software.
>If you're really lucky, at some apertures, it may not even be noticeable
>without close examination. You could be fortunate the damage is to rear
>lens. If light is refracted, it wont be moved from where it should fall by
>much.
>Look at it like this to see what I mean:
>
> ------ Front glass (scratch on
>front
>glass)
> /\
> /| \
> / | \ (possibly large displacent)
> ---------- Rear glass
> --|---|----|--- Film plane
>
>
> ------ Front glass
> |
> |
> |
> ---------- Rear glass (scratch on rear
>lens)
> /|\ (possibly small displacement)
> ---|-|-|---- Film plane
>
>If a vertical line were the proper path, you can see that a scratch on the
>front of the lens would mean a larger displacement from the proper path by
>the time it reached the rear of the lens. But from the rear of the lens to
>the 'film plane' may be small enough that the light path hasn't deviated by
>much.
>Another possible effect could be just (or and) some false colours due to
>the
>damage since the blue and red ends of the spectrum may refracted
>differently
>by the damage.
>You may also be lucky in that the damage seems to be mainly just below
>centre (near the area where the rays are normally refracted least by the
>lens - which may help reduce the effects of the damage). Unfortunately, it
>is the are where most people and cameras usually focus and meter most with.
>Can you see the damage when yoiu look through the viewfinder? If you can
>see
>it, so will your film/sensors. If you can't see it, then you might be lucky
>enough to still get decent pictures.
>At worst, you can try re-selling the lens to recover your losses (at least
>to some extent).
>Allan
>
>PS No trees were harmed in the sending of this message and a very large
>number of electrons were asked their permission to be terribly
>inconvenienced. (And threw a party for them afterwards for being really
>cool
>about it).
>
>Disrupting the unnatural balance that you, as a conscious human being and a
>confused mass of energy, have created.
>-Disturb the mind -
>
>
>
>
> >From: Moose <olymoose@xxxxxxxxx>
> >Reply-To: olympus@xxxxxxxxxx
> >To: olympus@xxxxxxxxxx
> >Subject: [OM] Re: ( OM) Photographs of lens damage
> >Date: Sat, 04 Nov 2006 03:45:31 -0800
> >
> >Brian Swale wrote:
> > > Hello all
> > >
> > > Recently I bought at an auction, a Zuiko 21/3.5, knowing it had some
> >kind of damage
> > > to the rear lens element. I did not know what kind of damage and could
> >not ask as the
> > > auction was closing soon after I discovered it.
> > >
> > > It arrived yesterday, and I found the damage was right into the glass.
> >Looks as though
> > > the rear lens cap has come off while the lens was joggling around
>loose
> >in a camera
> > > bag, and rubbed against something hard. Cleaning does not shift the
> >marks.
> > >
> > >
>http://homepages.caverock.net.nz/~bj/photography/zuikoholics/recent5.htm
> > >
> > > It will be interesting to see if this damage has any discernible
>effect
> >on images.
> > >
> >Oh, bad luck, Brian, I'd hoped it wasn't so much damage. It will almost
> >certainly affect images if left as is. Light will be refracted and
> >reflected and cause at least flare, if not actual bright spots.
> >
> >T'were mine, I would cover the inside of the damaged areas with
> >something black, finepoint Sharpie ink, perhaps, to kill reflections and
> >refractions from the rough edges. It's possible that there will still be
> >a darker area in images, but that should be easier to correct. Perhaps
> >with a retrofocus design, where the rear node is actually behind the
> >rear element, even that won't happen.
> >
> >I know you aren't into post processing and have computer limitations.
> >Still, one possibility if there is a darkened area would be to take an
> >image of a simple white subject, reverse it, and make an exposure
> >correction mask that just compensates exposure where it is affected. by
> >the damage.
> >
> >The other thing I would do is keep an eye out for the same lens with an
> >undamaged rear element but with damage elsewhere which renders it
> >inexpensive.
> >
> >Moose
> >
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