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Re: [OM] New 90mm Zuiko macr

Subject: Re: [OM] New 90mm Zuiko macr
From: Moose <olymoose@xxxxxxxxx>
Date: Thu, 9 Feb 2023 20:34:30 -0800
On 2/9/2023 1:44 PM, Mike Gordon via olympus wrote:
Come closer Moose writes:
<<<<but as expected the
<<<working distance is a bit tight.  Close focusing distance in S macro mode 
(odd ball switch
<<<which moves lens elements and lose max aperture goes to F5 or F5.6, (reviews 
were discordant))
<<<is 8.8 " with working distance 2.5."  (2:1 magnification).  Working distance 
at 1:1
<<<only 3.7".

That's weird. Just set 60/2.8 to 1:1, and working distance is ~3.25 in.

Yes, it is weird.  Pulled those numbers from reviews--not clear if the "S 
macro" switch was engaged--suspect much shorter FL with that switch set.  People 
describe hearing lens elements moving around.  It seems the 1:1 setting  on the 60 mm 
must be true 1:1 mag

Correct.

and not FF equivalent, i.e image produced is really at 1:2.

Which image?. The reproduction ratio, which comes from the cameras used in making printing plates, is literal, not relative. A contact print is 1:1, whether 8x10" or half frame.

The "Eq" Oly mentions deals with the relative sensor sizes. Shoot a 2 Peso Mexican antique coin, which happens to be 12 mm, @ 1:1 on FF, and the coin will fill half the height of the sensor. Shoot it @ 1:1 on µ4/3, and is will fill 92 % of the height of the sensor.

Printed on 4x5 paper, the coin from the smaller sensor will be almost twice the size of thee FF print. Ignoring the format shape difference, 1:1 on µ4/3 is the equivalent of 2:1 from a FF sensor.

The nomenclature is confusing and Oly didn't make it any better by often citing 
the FF equivalent magnification but the image is a crop.

See above. "i.e image produced on the sensor is really 1:1, while the image printed, or on screen, at a different magnification or dpi, is really at 1:2. "

Relative Ratio Moose

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