The 50/2 macro is a great lens for close work, so I can not agree that it is
not "well suited" for such a subject. It will extend to half-life size
(1:2) with no extension and produce results as precious few other lenses
can, at any price. This is its *optimal* range. With a 25mm extension tube
life size (1:1) can be achieved. If you plan to take images of small detail
areas, the 50/2 will work just fine. Your working distance will be very
short, making lighting more difficult, and you will be beyond the optimal
range of this particular lens. Other lenses optimal ranges may be needed
for best results.
For magnifications greater than 1:1 Olympus recommends reversing the 50mm
macro. Doing so extends is range up to 3.5x, or a subject area
approximately 10mm x 7mm. Just for reference, the optimal ranges for the
macro (bellows) lenses are:
Lens Magnigication range
Bellows auto-tube
135 f4.5 0.1 - 0.5 0.1 - 0.4
80 f4 0.5 - 2.0 0.5 - 1.1
38 f2.8 2.3 - 6.7 3.1 - 4.2
20 f2 5.2 - 13.2 6.7 - 9.2
--------
38 f3.5 1.8 - 6.2
20 f3.5 4.3 - 12.5
Sources: Olympus Manual for Macrophotography Group (8/79) and data sheet
for Zuiko auto-macro 20mm 1:2/38mm 1:2.8 lens.
Note: decimal rounding of magnifications subject to estimation error by
these tired old eyes straining through bifocals <g>.
This does make me a tad curious why the magnification ranges for the older
20 & 38 macros are slightly less than the newer OM mount versions. That
much of a change in the optical formula?
As for getting 5-6mm DoF, I don't think so. At magnifications greater than
1:1, DoF is nearly zero, even fully stopped down. Oly recommends focus
screens 1-4, 1-11 and 1-12 for these applications. I'm sure the 2-4 version
is an improvement.
John P
______________________________________
there is no "never" - just long periods of "not yet".
there is no "always" - just long periods of "so far".
> Tom's macro inquiry got me thinking about an upcoming project: Shooting
> close-ups of an ornate pocketwatch that belonged to my grandfather. I
> have the 50/2 macro, but this lens isn't well suited for really close
> work (I'm told) or (I'm also told) for use with extension tubes. Why?
> Would I be better off with the 100 2.8 (or the 50 1.8) and extenders? I
> probably need about 5 or 6mm of critical DOF.
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