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Re: [OM] This is the first time...

Subject: Re: [OM] This is the first time...
From: clintonr@xxxxxxxxxxxxxxxx
Date: Mon, 28 Apr 2003 19:43:53 -0500
Just to add my two cents....

Richard Smith wrote:

> >1.When might one want to lock up the mirror on an OM1, OM2, and
> OM2n?And how is >this done?
>
> The 1's have a mechanical arm that lifts the mirror to reduce
> vibration for critical photography (micro-, micro-, astro-photography,
> etc.).
>
> The OM-2 and early versions of the OM-2n had a switch that activated
> the camera's circuitry whenever the mirror was lifted, so a mirror
> lock-up mechanism was not incorportated in that or subsequent OM's.
> Late on, it was discovered that this switch was superfluous on the
> OM-2n, and in fact could cause problems with databacks misfiring and
> so forth, so it was "dropped" (not included) in later production
> OM-2n's.  In fact, as part of a routine overhaul the "sub-switch" as
> they were called was to be either disconnected or removed entirely
> whenever encountered.
>
> As a result, it is theoretically possible to incorporate a mirror
> lock-up lever in an OM-2n, except that there was no provision for the
> mirror lock-up arm on the front casting.  Never the less, I did, on
> one occasion, "modify" an OM-1n front casting to accept parts from a
> 2n and was well on my way to making an OM-2n with mirror lock-up --
> it's around the office somewhere....
>
> This ("mirror lock-up", the feature on an OM-1 or OM-1n, used to
> reduce vibration) should not be confused with the mirror mechanism
> "locking up" on other models.  The OM-2 and OM-2n, as well as many
> other, later, OM's are designed to "lock up" if the batteries are dead
> or missing, or if there is a malfunction in the camera, and on some
> models you can also "accidentally" lock the camera up by winding the
> camera while the shutter is open.  When that happens, on some models
> the mirror rises completely to the top of the mirror box, while on
> others it only rises half way.  Depending on the camera, you may have
> to replace the batteries and/or "reset" the camera in some way to
> render it functional again.
>
>
> >2.I see ads for lenses that claim ?absolutely no oil on the blades,?
> or ?the diaphragm is oil >free.?What is the nature and cause of this
> problem that many Ebay sellers (especially) say >they don?t have?
>
> Grease from the helicoids (the threaded barrels that turn to move the
> lens in and out) can leech into the aperture blades or mechanism on
> some lenses.  When that happens, the aperture usually won't work
> properly.  This (sluggish aperture blades) is somewhat common on some
> lenses, extremely rare on others.  The most common Olympus Zuiko
> lenses with this problem are the later versions of the 50mm f/1.8,
> where the serial number is at the side of the rear end of the lens,
> though all lenses of this type may have oil in the blades or
> mechanism.  We see a significant number of "generic" non-Olympus zooms
> with this problem, too.
>
>
> >3.I know ?it depends,? but should I buy a T32 or a T20?
>
> The model numbers reflect the "guide number" in meters, or power, of
> the flashes.  In short, the T-32 is half-again more powerful as the
> T-20, has a TTL connection, bounce capability, and so forth, but it is
> also heavier and bulkier, and therefore more prone to breaking when
> used carelessly.  Hence, I would not recommend mounting it directly on
> top of a camera using it's shoe.  If you are shooting "casually", get
> the T-20.
>
>
> >4.Ever hear of reversing a 50mm lens on my OM1 and using it for close
> up shots?Why in the >world should this work?
>
> Consider the ratios involved:  In normal use, the distance from the
> rear of the lens to the film is only a few millimeters, while the
> distance from the front of the lens to the subject is many meters.
> Turn that around and put the "long" leg toward the film and the
> "short" leg to the subject, and you'll see that with the same ratios,
> you can get really, really close to something!
>
>
> >7.Do you think there is a quality difference between the Om1 and
> Om2n, or are they all the >same high quality?
>
> "Quality" will be the same, but most original OM-1's will be several
> years older than most OM-2n's.  Some of the problems with the early
> OM-1's are related to the plastic becomming brittle, so that's one
> reason to buy a newer body to begin with.  Also, the OM-2n had several
> functional improvements over the original OM-2 which serve to make it
> more reliable to begin with.  Given the "either/or" choice, I'd go for
> the OM-2n.  Of course, I keep several OM-1 and OM-1n bodies around for
> studio/flash work, an OM-2n for fun, and an OM-4t for outdoor/ambient
> light work.
>
>
> >9.What is the best way to clean a lens without damaging it?
>
> Carefully.
>
>
> >10.Why is a 135mm/2.8 a telephoto lens, whereas a 135mm 4.5 is a
> macro lens?
>
> They are both "telephoto" lenses, in that they have longer focal
> lengths.  The "macro" lens is just designed/optimized for higher
> quality images with greater magnification at closer focusing distances
> -- in short, if focuses closer and makes a better image when used that
> way, as opposed to a "normal" telephoto lens.
>
>
> >11.If Ebay is any measure, are prices for Olympus OM cameras, lenses,
> and accessories >skyrocketing?Is this something we can expect to
> continue?
>
> Don't dump your 401K!
>


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