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Re: [OM] 20mm f/3.5 Macro (non-MC)

Subject: Re: [OM] 20mm f/3.5 Macro (non-MC)
From: Tim Hughes <timhughes@xxxxxxxx>
Date: Sun, 11 Oct 2009 17:17:57 -0700 (PDT)
One reason I like flash for micro/macro is you don't have to worry at all about 
vibration , provided the flash predominates.  In micro work, light becomes a 
bigger problem, so it almost requires flash.  TTL flash as in many OM's, works 
so well for macro and using multiple flashes allows easy back fill so 
background does not blacken out. I often like a manual flash for background 
fill and ttl for foreground. Unfortunately OM flashes have such a limited 
manual set range, you need a non- OM back fill flash like a Sunpak, which has 
6-8 stop range in 1/3stop increments.
 
Tim Hughes

--- On Sun, 10/11/09, Carlos J. Santisteban <zuiko21@xxxxxxxxx> wrote:


From: Carlos J. Santisteban <zuiko21@xxxxxxxxx>
Subject: Re: [OM] 20mm f/3.5 Macro (non-MC)
To: olympus@xxxxxxxxxxxxxxxxx
Date: Sunday, October 11, 2009, 4:37 AM


Hi Dawid, Ken, Chuck, Moose and all,

From: Dawid Loubser <dawidl@xxxxxxxxxxx>
>I just wanted to comment that I think the 20mm f/3.5 that I received
>from Clay is an incredibly early (and, consequently, rare?) version.
>It's not multicoated (i.e. no "MC" marking).

From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
>Without regard to the 20mm in particular, not all MC Zuikos are marked
>as MC.

The Zooms, Macros and some special lenses didn't follow the x.Zuiko/Zuiko
MC/Zuiko markings... The latest scheme can be recognized by the order of
focal length and aperture: these late lenses have the focal lenght alone
first, and then the aperture (e.g. '24mm 1:2') whereas the older lenses (MC
or not) have them reversed, with a 'f=' before focal length (e.g. 1:2
f=24mm)

Please note that this late lettering does NOT guarantee the presence of
multicoating, although most are -- AFAIK, the 135/3.5 was NEVER multicoated,
even when marked 'Zuiko Auto-T 135mm 1:3.5'. Of course, when a lens is
marked MC, it _is_ multicoated.

From: Dawid Loubser <dawidl@xxxxxxxxxxx>
>My OM-1 manual, which dates from 1974 or so (i.e. it pre-dates the
>existence of the 21/2.0 and 50/1.2 lenses) already refers to the
>20/3.5 "MC" Macro (along with the 80/4.0 MC macro, also manual
>diaphragm) lenses. So - this means that only from about 1972 - 1974
>were these very very early single-coated Macro lenses made?

Can't say about this, I've never seen 'in person' those macro lenses. Some
lenses were MC from the start, like the fast wides -- except the 21/2,
introduced later.

The 50/1.2 (always MC, marked or not) appeared much later than the early
G.Zuiko 55/1.2 -- always single coated, if I'm not mistaken.

From: Dawid Loubser <dawidl@xxxxxxxxxxx>
>Quite special indeed... I also love single-coated lenses for B&W work,
>and I must say, the quality of the 20/3.5 (on all aspects of image
>quality) is stupendously good,

Some lenses are great even in single-coated version -- even in flare
resistance. The unrelated 28/3.5 comes to my mind, I have used it
successfully in either B&W, colour film or digital. OTOH, the 135/3.5 would
definitely improve from multicoating... but never had it :-(

>as long as you use the lens
>at relatively wide apertures. Have not done scientific testing, but
>from images I actually get the impression that wide open it's already
>at peak performance.

From: Moose <olymoose@xxxxxxxxx>
>The diffraction mavens have previously opined that the 20/3.5 is indeed
>already slightly diffraction limited at f3.5 and gets progressively
>softer as it is stopped down. As I recall, speculation was that the
>20/2 replaced the f3.5 in part to avoid diffraction limiting, but
>only wide open.

That makes a lot of sense. As a funny note, the older 20/3.5 Macro is like a
reversed Tessar (4 elements, 3 groups => highly flare resistant), wheras the
later 20/2 is a classic Planar/double-Gauss design (6 elements, 4 groups)

From: Dawid Loubser <dawidl@xxxxxxxxxxx>
>Oh, and another question - what do you guys do to tame vibrations from
>an OM-1 when using a lens like this for natural-light work? (i.e.
>shutter speeds anything from 0.5 to 20 seconds) ? I thought my
>old Linhof tripod was reasonably solid, but even with mirror lockup,
>at these high magnifications the image is jumping all over the show,
>almost impossible. Thus, am generally using flash for the moment.

From: Ken Norton <ken@xxxxxxxxxxx>
>The short answer is to NOT use the OM-1.  The OM-1 has that little >issue
with the aperture stop-down mechanism that shakes the camera
>(even with mirror lockup) like it's coming off of a high.

From: Dawid Loubser <dawidl@xxxxxxxxxxx>
>That really sucks, I love my OM-1n, but I am happy to perhaps relegate
>all Macro shooting to the OM-2n (which, I must admit, does appear to
>be a lot smoother).

Shouldn't be that way. However, I have the impression that the oldest OM-1
(pre-MD) and OM-2 (older, uneven mettering pattern) feel smoother than later
OM-1 and OM-2, including the -n series...

>Hmm - my OM-1n must have bad internal bumpers then, because it really
>does vibrate a bit more than the OM-2n.

Most likely. The foam at the mirror isn't really intended for light sealing,
but mostly for damping.

From: Ken Norton <ken@xxxxxxxxxxx>
>An OM-2, 3 or 4 series body (even the OM-2000) will be much smoother in
>this circumstance.

I don't think a 2/2n would make things better. (Nearly) all OM cameras
suffer from the aperture issue, but some models have a workaround...

From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
>An OM-2S, OM-4x or OM-2000 will pre-fire the mirror and stop down
>mechanism when used with the selftimer.

...this is it. The OM-3 doesn't have a self timer, so I'm afraid it won't
help -- I've never handled one, though.

>The mirror and stop down will
>fire after about 2 seconds thus giving about 8 seconds for the
>vibrations to damp down before the shutter fires.

Never seen that behaviour... mine do pre-fire both mirror and aperture when
pressing the release button, so they have the full 10? seconds for the
vibration to extingish.

>Actually, I'm not
>100% sure the 2S also pre-fires the aperture along with the mirror but
>I'm not at home to check it out.  But the stop down mechanism is the
>major vibration culprit so be sure to check.

Yes, it does prefire. BTW, the 2S and the PC/40 have another measure against
vibration: the aperture mechanism bears a delayed action (because of Program
capabilities) which smoothens things quite a bit.

Wonderbricks and other 'modern' cameras have no springs at all, everything
is motor driven. They _are_ much smoother, but at the cost of an increased
shutter lag -- and I'm not talking about AF, I discarded the (manual focus)
Contax Aria because of this.

From: Moose <olymoose@xxxxxxxxx>
>Others have already weighed in with excellent advice. To make it
>perfectly clear, an OM-2 or OM-2n is no improvement on the OM-1(n) for
>vibration.

Amen to that. As already said, I don't think the OM-3 is any better,
although the added inertia of the secondary mirror _may_ improve things a
little bit...

>You must go to an OM-2s (why it's called an OM-2_ is a
>mystery to me),

I agree, I think something like 'OM-4 Lite' should have been much more
appropriate...

>OM-4 series,  OMPC (OM-40) or OM2000 body and use the
>self timer to pre-fire mirror and aperture to reduce camera induced
>vibration.

Quite effective, indeed.

From: Dawid Loubser <dawidl@xxxxxxxxxxx>
>But as I said, my main issue is vibration not from the mirror, but
>when the shutter opens (and thus, the notorious aperture stop-down
>mechanism).

Even when the mirror and aperture pre-fire, the opening shutter does induce
a bit of vibration...

From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
>Other means of vibration reduction is to place your hand heavily on the
>camera during exposure or use a bean or shot bag.

From: Moose <olymoose@xxxxxxxxx>
>Also, a bag filled with lead shot (coated for your health) will be more
>effective than light things like lentils, rice, etc. When used on a
>tripod mounted, i.e. horizontal, camera, be sure to have it resting on
>both body and lens.

Always recommended for high resolution and/or high magnification work --
ESSENTIAL with some lenses (e.g. 200/4)

From: Dawid Loubser <dawidl@xxxxxxxxxxx>
>It is amazing how well a human being damps vibrations, no? The OM-1 is
>the only camera I've used with which I can get tack sharp 1/15s
>exposures hand-held (say, with a 24mm lens) but which absolutely sucks
>on a tripod for similar exposure durations.

Have you ever tried rangefinders?

From: Ken Norton <ken@xxxxxxxxxxx>
>Long answer is to use a LONGER shutter speed.  As a general rule, you
>should avoid 1/4 to 1/30 second with all OM bodies, but especially
>the OM-1. When you use a longer shutter speed than 1/4 second, the
>percentage of the exposure that is affected by vibration is greatly
>reduced.  With a 2-second exposure, for example, you will have no
>shutter-vibration blurring.

There is the well-known 'hat' method -- put a black cardboard in front of
the lens, release shutter, wait several seconds for the vibration to
disappear, and _start_ actual exposure by lifting the black cardboard.

Commonly used in astrophotography, it seems however tougher to implement for
macro, where things are much closer...

From: Dawid Loubser <dawidl@xxxxxxxxxxx>
>Anyway, my plan B is to potentially think of building a leaf shutter
>(like from an old busted Mamiya RB lens, those shutters induce an
>effectively zero moment of inertia to the system when they fire) in
>between the lens, bellows, and camera somewhere. That might be an
>all-round better solution, I have found leaf shutters to be much
>superior for delicate Macro work

Seems quite interesting, but rather difficult... please let us know if you
experiment about this!

>For example, this shot I posted previously was with the 20/3.5 with
>natural light, ~4 seconds exposure at f/16 (massively diffaction
>limited, but needed the DOF).
>It came out fine with the OM-2n (auto tube + bellows), not sure that
>my OM-1 would have settled down enough by then.

<
http://fc01.deviantart.com/fs46/f/2009/236/9/d/Seedling_by_philosomatographer.jpg
>

Nice result anayway!

Cheers,
-- 
Carlos J. Santisteban Salinas
IES Turaniana (Roquetas de Mar, Almeria)
<http://cjss.sytes.net/>
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