>> In article <4ph7ps$fup@nwd2nws1.analog.com>, sgold@.adsdesign.analog.com
>> says...
>> >Any thoughts on the wisdom or lack thereof of using one of the Nikon
>> >closeup lenses on the 105mm 2.8 Micro-Nikkor? I'm not necessarily
>> >after more magnification, but mainly seek greater working distance
>> >so as not to spook butterflies and dragon flies.

>In article dnp@newsstand.cit.cornell.edu, d_ruether@hotmail.com (Bob Neuman) >writes:
>> This is unlikely to work for you (though the Nikkor "T" achromats
>> can provide excellent sharpness with many lenses), since close-up
>> lenses work by shortening the lens focal-length without changing
>> the barrel length, hence the closer focus. Try a 1.4X (or 2X, if
>> your light source is flash, allowing the small apertures needed
>> for excellent sharpness) converter for more front space with the
>> same magnification. BTW, under some conditions, butterflies and
>> dragonflies seem totally unaware of the photographer's presence,
>> no matter how close the lens (seems to happen if you can get one
>> flash exposure before the insect disappears - after that, anything
>> is possible [I have some nice dragonfly head pictures....]).
>> Hope This Helps

In article <4pjs6g$kcu@nwd2nws1.analog.com>, sgold@.adsdesign.analog.com says...
>Thanks for your answer Bob. I didn't realize the optical principles
>involved. Would you happen to know which converter(s) are best for
>use with the manual focus 105/2.8 micro?

In this article, "Hope This Helps" ("BN" aka "DR", but not the, uh,
"flower"-related one...;-) says...
The best converters I have used that fit Nikon are the Nikkor TC200/201,
Nikkor TC14A, and the Vivitar 2X Macro Converter - for lenses with glass
near the rear. For lenses with sufficient rear space to clear the
projecting glass of the long-lens type converters, or when using tubes,
the Nikkor TC14/14B/14C and TC300/301 converters work well. The 1.4X
converters generally produce sharp images with most lenses by mid
apertures, and with a few lenses, at wide apertures. The 2X converters
do not work well with many lenses, but using small apertures usually
produces good sharpness, even when the combination is not ideal. With
good matches, good performance can be had by mid apertures, but only
rarely are 2X converters sharp at wide lens apertures. The 105mm f2.8
MF Micro-Nikkor can be used with all the above mentioned converters
at f11-16 for good results (though the long-lens converters will need
to have a sufficiently long extension tube placed between the converter
and lens to avoid glass contact).
Hope This Helps