In article <329350E7.1A8@ucrac1.ucr.edu>, donp@ucrac1.ucr.edu says...

>I have a couple of more general questions. What is the difference
>between the Nikon PB6 and the PB4, I'm interested in the a PB6, and the
>information I have regarding the Nikon bellows says nothing about a
>PB4. Also what are some accessories that I would need when using the
>bellows, as you can tell I've never actually used one some I interested
>in any pertenant comments or suggestions.

Bellows used to be popular accessories, until enough people realized
that they are far more awkward to use than macro lenses (big, heavy,
generally no lens auto diaphragm, maximum focus is far too close with
short lenses, minimum focus is FAR too close with short lenses,
lenses used with them are usually not well corrected for the
magnifications provided by using the bellows). The PB-6 does provide
a bunch of options, depending on what accessories you buy, but for
straight macro work going up to about 2X, a good macro lens combined
with a converter, tube, and/or achromat may be better. For very high
magnifications, Nikon (and others) made a set of special lenses for
bellows work (I just tried the Nikkor 35mm f4.5 - excellent by 5X,
optimized for 12X). The PB-4 does provide tilt and shift (which I
use about once a year with a 150mm Vivitar VHE enlarging lens
(actually, a Schneider Componon-S, relabeled) press-fit into a
Nikon BR-2 ring for a bayonette, and used with a strong skylight
filter to shift the lens color balance closer to Nikon-normal.
It allows me to take long-lens photos of near-planar subjects
with near universal DOF, but it is very awkward to use...
Hope This Helps