On 6/27/2021 6:38 PM, Mike Gordon via olympus wrote:
<<Curious what the
<<working distance was with the 100-400 + diopter?
As you know the max working distance is solely a function of the diopter. The
Fl of the diopter is in its name--works out to 0.76 diopter. So max working
distance
is 1/0.76 m or about 4 1/3 ft. Good enough for many nervous little critters.
The FL of the lens attached determines the mag.
In this case, with this lens (and the Oly 100-400), that is the crossover point, as close focus without diopter lens is
4.25 ft.
With the C-U lens on a Xume magnetic filter ring, just pop it on and off for
under and over 4' focal distance.
This is why the almost mythical Pentax T226 achromat, giving a longer working distance, isn't particularly useful with
these lenses; less magnification and no working distance advantage.
A. Chromatic Moose
--
What if the Hokey Pokey *IS* what it's all about?
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|