My favoured setup for magnifications in the region of 1.5x life size is:
- AFD 105/2.8 micro.
- PN-11 with RRS B5 plate
- AI compatible camera (previously FM3a, now D600)
- Tripod and ball-head with Arca-Swiss clamp
The AFD 105 micro is preferred for this setup because it is compatible with the PN-11 (AFS G micros are not usable with the PN-11 or other Nikon extension tubes). The 105mm focal length setup gives a comfortable working distance for this magnification. A longer lens with more working distance will make it is harder to locate the small target in the viewfinder – unless you are lucky enough to have set up the camera pointed more or less directly at the subject and in focus, all you will see is an out of focus blur with little clue about which way to focus or move. A longer lens also requires more extension to achieve the same magnification which can become unwieldy.
The PN-11 is a large extension tube at 52.5mm (half 105mm). Therefore it is large enough to give a useful increase in magnification with the 105 micro. The magnifications that can be achieved range from 1:2 to about 1.7x life size. However I don’t recommend using this combination for magnifications less than 1:1 since the lens will be “focused” for longer distances and the optics won’t be well configured for macro shooting, resulting in field curvature and other aberrations.
When macro lenses with floating elements (CRC) such as the AFD 105 micro are used with extension tubes, best results are obtained when the lens is focused at or near to the close focus limit where the lens optics are optimally configured for macro photography. The general rule is to use the shortest extension tube to achieved the desired magnification, and rack the macro lens all the way out. So, for magnifications just beyond 1:1 I'll use the shorter PK-13 instead.
The PN-11 features a rotating tripod mount, which enables the camera to be supported nearer the centre of balance for improved stability and less stress on the lens/camera mounts. It also permits you to rotate the camera from horizontal to vertical, or anywhere between, while staying on target. Many macro subjects such as flowers look equally good in vertical and horizontal formats so this feature is very useful.
My PN-11 has an Arca-Swiss type RRS B5 quick release plate. It fits in the tripod in a fore-aft orientation which means the clamp can be used as a short focusing rail – once the tripod is in position and the lens is focused to more or less the desired magnification, focusing can be achieved by moving the whole system within the clamp. Critical focusing can then be completed by adjusting the focus ring without affecting the magnification or framing too much.
