Nikon Microflex PFM Microscope Assembly
The Nikon Microflex is designed to allow high-quality microscopes to be mated to a camera with a Nikon bayonet mount,
a 39mm Leica screw mount, and other types of mounts. The PFM device has a built-in leaf shutter to prevent vibration
that might be caused by the action of a mirror or focal plane shutter.
The Nikon Microflex was introduced with the Nikon F, around 1959. Early examples of the Microflex had no designation.
Of the three versions that were made, the second and third versions were designated "PFM" to differentiate them from
other Microflex devices.
The configuration is a tube with a microscope camera on one end and a microscope attached to the other end. In the
middle is an eyepiece that can be used to view the object to be photographed. It has diopter settings from -4 to +4.
Viewing through the eyepiece is facilitated by a small prism that must be pulled out of the light path to the camera
by pulling a chrome knob on the same tube as the eyepiece, mounted 90 degrees from it. The knob can be pulled and
twisted to cause the prism to move back into the position for eyepiece viewing after the leaf shutter cycles.
The first microscope camera was built around the Nikkorex F design, and later versions used the Nikkormat body
configuration. A bayonet adapter allowed the Microflex to the mated to a standard Nikon F body. These cameras
did not have a mirror box or shutter because a variable speed leaf shutter in the PFM mechanism controlled exposure.
The speed settings for the Type 2 and 3 PFM were T, B (bulb), 1 second, 1/2 second, 1/4 second, 1/8 second, 1/15
second, 1/30 second, 1/60 second, 1/125 second, and 1/250 second. The Type 1 speed went to 1/300 second.
The units have a sync socket for a flash gun and a cable release socket.
Other variants of the microscope adapter were developed in the mid-1960s, including the Microflex EFM that had a
built-in exposure meter. The meter had a Cadmium Sulfide (CDS) sensor powered by a PX 625 button battery. A
match-needle exposure setting method was used.
Around 1967 Nikon introduced the Microflex AFM which automatically set the proper exposure. A manual exposure
mode was also available.
The Microflex CFM was designed to use a 16mm motion picture camera. It had a built-in intervalometer for use in
making time-lapse movies. Nikon sold an adapter for use with the Bolex H 16 movie camera.