Nikon MD-4 Motor Drive

Other than the professional grade Motor Drive like the MD-4 or the MD-2 for the Nikon F2 series models, motor drives designed by Nikon for the mid compact models like the MD-12, MD-14 or MD-15 were not provided with a power rewind feature. The MD-4 in this case, is impressive in its performance. Power rewind with Ni-Cd just takes only 4.5 sec for a 36 exposure roll.

Rewind Slides 1 (R1) and 2 (R2)

When one LED lights up to signal that the film is at an end, you must rewind the film. To simplify this operation, the MD-4 features completely automatic film rewinding. Depress the lock button (0) on R1 and push the slide to the left (1). Then while holding R1 in position, push R2 up (2).

Immediately the film will start rewinding. When the sound becomes more high-pitched or tension is less, this indicates the leader has been completely rewound back into the cartridge. To stop the rewinding action, push R2 back down and immediately R1 will spring back into its original position. When you perform rewind action R1 & R2, the rewind shaft will project upwards from the centre of the electrical contacts into the camera body to begin auto film rewinding. However, the rewinding feature will activate even if there is no film inside the F3 body.

Note:If the film is automatically rewound in cold weather, static electricity charges may cause accidental exposures resembling lighting bolts to appear on the film. To prevent this from happening, push R1 to the left and rewind the film slowly by hand with the camera's film rewind crank.

If you were using the frame counter, it moves from "0" to the orange dot position as soon as R2 is pushed up. Rewinding time for a 36-exposure roll of film with alkaline- manganese batteries is approximately 8 sec.; with the optional MN-2 NiCd Battery Unit, it is reduced to 4.5 sec.

Gold-plated contacts inside the camera provide a terminal for operation of optional data backs. The F3/MD-4 combination can be used for remote and even unmanned photography with Nikon intervalometers, wireless and Modulite controls, also with external power sources and with a special bulk film and a few Databack options.

MF-6 has an upgrade in MF-6B. I don't know the difference between them, mail me if you do. This is also the standard back for Nikon F3P and F3 High Speed cameras.

To avoid the film leader completely rewinding inside, you can use the MF-6(B) camera back or MF-18 Databack

When it relates to electrical contacts, other than the two that are used for Databack and bulk film back. The MD-4 has six electrical contacts that interact with the camera when you remove the motor drive coupling cover. These electrical contacts and mechanical couplers provide for operation with motor drive MD-4 with a F3. It is by way of screw-on type connection to relay signal:

1) Closing curtain signal
2) Electromagnetic shutter-release start signal
3) Film-advance completion signal
4) Power source signal
5) 16 sec.-hold signal
6) Release-metering signal

To understand more: Click here

Note: Originally, there were seven contacts underneath the camera body and as well as the motor drive. For some unknown reasons, the extra contacts were never utilized but they still remained there.

Frame Counter A subtractive-type frame counter is built into the MD-4. For normal shooting, set the counter to the orange dot and forget it. At this setting, the counter is disengaged and the motor drive stops automatically when the film tension increases at the end of the roll.

However, in below-freezing temperatures, film becomes brittle and easy to break. Therefore, to prevent the film from being accidentally torn, set the frame counter to the number of frames on the roll. When the counter reaches "0," the motor drive automatically shuts off before the film is damaged. One LED also lights up as a visual indication.

To set the counter, turn the counter setting dial to the right until the desired number is aligned with the white index 36, 24, 20, and 12 are in red corresponding to the number of frames in commercially available cartridges. You can also shoot short bursts by setting the counter to the number you want (Fig. 1). When the counter reaches "0" the motor drive stops and one LED lights up (Fig. 2). To reset the frame counter for another burst, first turn the counter setting dial to the orange dot and the LED will go out (Fig. 3). Then you can rotate the counter to the desired number. Before resetting the counter, make sure to check the camera's frame counter to determine whether there are enough exposures left on the roll for the next burst.

			Note: If you rewind the film before the frame counter reaches "0" the counter will not reset properly to the orange dot. Therefore, before starting to shoot your next roll of film, make sure to reset the counter to the desired setting. The film becomes brittle in low temperatures In cold climate, be careful not to over estimate the number of frames remaining on a roll of film since this may result in the motor pulling the film off the supply spool or damaging its perforated edges. It may be a good practise to set the frame counter to one less than the number of frames remaining on a roll of film. For example, if you load a fresh 36-exp. roll, set the frame counter to 35.
Fig 1	Fig 2	Fig 3

The Motor Drive looks slightly tilted to the back if viewed sideways This was designed specially to prevent the camera with the drive attached from tipping over on its face when set down. How well was it ? Try mounting a 135mm f2.8 Nikkor lens, the MD-4 will still stand erect without without tipping over !

| Left and Right View of a MD-4 mount on a F3 |

Considering the fact the key components are made of metal, weighing only 480g I don't complain it is too heavy... in exchange for durability and reliability.