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[OM] What is a macro, and what's in it? [was OM-5D macro comparisons]

Subject: [OM] What is a macro, and what's in it? [was OM-5D macro comparisons]
From: Moose <olymoose@xxxxxxxxx>
Date: Mon, 30 Jan 2012 14:59:43 -0800
On 1/30/2012 11:36 AM, Joel Wilcox wrote:
> ...

First, let me say that this is not a macro comparison. absent clear referents, 
it looks to me as though the full subject 
width is somewhere between 7 and 14 inches,a  repro ratio of 1:10 to 1:5. Based 
on the apparent slight softness of the 
90/2 and my experience with on, maybe closer to 1:5.

Marketing labeling aside, that is to me close-focus, not macro. Who knows what 
the term really means? Oly labeled 
everything from the 90/2. which gets soft by 1:4, to the 20mm lenses designed 
to go to 12:1 (12x) as Macro. The called 
their microscope photography equipment Micro. Nikon called their lenses that go 
down to 1:2 ad 1:2 Micro.

> I am pleased with the lowly Z 50/3.5.  I believe it acquits itself more
> than adequately against the 55/2.8 macro.  I was surprised that its
> excellent contrast, if anything, may beat the Nikk*r.  This is a MC
> sample.

It puzzles me that people so often refer the the 50/3.5 as somehow lowly, like 
it was designed as a cheap alternative to 
something else. I don't believe that was the case at all. As part of Oly's 
first round of lenses for OM, I think it was 
designed with little compromise as a relatively expensive lens.

The 50/2 Macro was part of the later cycle of faster lenses, perhaps even a 
third wave. It seems to me that all it added 
was a faster maximum aperture and greater cost and weight. Both lenses are 
specified as for use from infinity to 1:2. 
One of my earliest posts to this list, after discovering it and Gary's lens 
tests, was an (over)analysis of those tests 
in which I suggested that all the 50/2 had over the 50/3.5 was maximum 
aperture. In subsequent correspondence with Gary, 
he said his later experience led him to believe the f2 and f2.8 result of his 
official tests understated the IQ of the 50/2.

Still, his tests were at 1:40, not close focus or macro magnifications, so 
really tell us nothing about greater 
magnifications. I've never used the 50/2 Macro. I have used the 50/3.5 at macro 
distances a lot, as well as other 
infinity to 1:2 or 1:1 macro lenses.

I believe the 50/3.5 is a really excellent lens for its designed purpose. There 
is a difference, to my mind, between a 
lens that will focus very close and a true macro lens. The true macro is 
designed for flat field, even resolution & 
contrast across the whole field and even illumination across the whole field. 
The 50/3.5 has those qualities in spades. 
It's really quite impressive at 1:2, clearly superior to the contemporary 
Tamron 90/2.5 and Kiron 105/2.8 and on a par 
with the much later design Tamron 90/2.8 AF.

Over the course of a few years, ending maybe 8-10 years ago, I helped a friend 
make a few hundred slides for his 
university lectures. These were slides of printed images, mostly from art and 
archaeology books. I made a copy stand 
from an enlarger, used photo floods at 45 deg. to the copy and a piece of  
glass to hold the copy flat. With a wide 
range of subject sizes and limited copy stand height travel, after some 
experimentation, I used the Zuiko 50/3.5 and 
Tamron 90/2.5 for all the work. As we never got down to 1:1, I saw no practical 
difference in performance between the 
two lenses. (BTW, I did some similar work with a better copy stand, Nikon Ftn 
and 55/3.5 Micro-Nikkor many years ago - 
before the Zuiko existed. It was excellent too.)

So what's my point? Simply that this was not a test of macro lens 
characteristics. The magnification is not really 
macro, subject is not flat, vignetting wouldn't be noticeable and edge 
sharpness isn't important. In fact, a lens with 
slightly convex focal field might outperform one with a flat field!

Lens design is always a series of compromises. To make a lens really good for 
1:2, flat field macro, compromises must be 
made in other characteristics. I wonder how a good general purpose lens, like a 
late 50/1.4, might have fared in this 
test? Probably depends on how big the subject actually is. I would also expect 
the 135/4.5 to perform very well at this 
distance and magnification.

> ...  For handling, the aperture ring placement of the Zuiko makes it much 
> easier to use on the 5D.  And it is
> small.  Despite its lack of speed I have no problem focusing it.
> Marvelous lens.

Indeed, but not for everything. It has the 50mm bokeh disease when focused 
close with a moderate to far away background 
even worse than the standard 50s. For that reason and the short working 
distance, I don't like it for outdoor work.

> What to think about the 90?  I think, for one thing, the test is not the
> last word on the 90.  Where the point of sharpest focus should be, I
> find the 90 to be a trifle softer than the other two lenses.  Look, for
> example, at the veins at the top of the petal that is the most vertical,
> just to the right of the bole of the flower:

Just get an old Tammy 90/2.5, 49 or 55mm thread model. Far better close up, 
almost as fast, just as good for general 
purpose and a great 180/5 macro with matched 2x converter. No prestige, but if 
results are what matters ... I sold my 
90/2 and kept the Tammy. (And I hardly ever sell anything!)

Moose d'Opinion

-- 
What if the Hokey Pokey *IS* what it's all about?
-- 
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