Convert a Pentax 645 into a Battery-Free, Totally Manual Operation Masterpiece

Everything about the Pentax 645 medium format camera is electronic/electrical. From the shutter speed mechanism to the film advance motor system, everything runs on 4 AA size batteries. These batteries are stored inside a hand grip that is mounted on the side of the camera. There’s an additional CR1220 coin cell battery for retaining settings that is stored in the camera’s base.

While this power system would generally be the end of the story, there are two problems with this setup. First is the noise generated by the film advance motor. This is a motor drive that is amped up on steroids. It is embarrassingly loud. Second, and much more problematic, is that the battery holder that slides into the hand grip can easily break. In this case, the clip that retains the battery holder can fail and without the holder locked into place with this clip, the camera will not operate.

Yes, in some cases, you can tape the holder into place with gaffer tape. Sure, it’s a stopgap measure, but it will work. Unfortunately, there’s the loud motor noise that you’ll still have to tolerate or ignore. There is another option, however, that can convert the purely electronic/electrical Pentax 645 into a blissfully muted, battery-free masterpiece. All you have to do is look at the camera’s bottom!

Taking Your Pentax 645 Off Grid

Ahem, I beg your pardon. Specifically, turn the camera upside down and you’ll see a round knurled knob housed in a pocket. This is the manual film wind knob. Simply remove this knob and thread it into the small opening located on the left-side, upper edge of the camera body near the lens mount. Now remove the hand grip, add a small piece of gaffer tape over the electrical contacts jack, and remove the CR1220 coin cell battery. You’ve now successfully converted your Pentax 645 into a totally manual operation medium format camera.

You can learn more information about the manual operation of this camera by reading pages 64 – 65 of Pentax 645 Operating Manual. There are a couple of extra caveats about manual operation that aren’t covered by these printed instructions. First, and foremost, twisting the manual film wind knob is a true labor of love. Depending upon your level of exertion, you should expect 10 – 15 short-travel cranks on this knob to advance the film, lower the mirror, and arm the shutter release.

Whereupon, when the red “armed” dot is visible in the window below the multi-exposure ring, you can now release the shutter. Although fixed at 1/50 of a second, you will still hear a loud “Kerchuck” as the mirror slaps upward inside the camera body. Furthermore, there is no “stop” when the film has been properly transported to the next exposure. Thankfully, the film does stop, even though you can continue twisting the film wind knob.

Additionally, there is no film exposure number counter with this manual operation mode. Therefore, you’ll have to keep track of each exposure of film. The easiest way to solve this minor inconvenience, is to insert a piece of paper (or, the end of the film carton) into the memo holder window located on the film holder. Then tick a mark on this paper for each exposure. When your tally system reaches the last exposure (i.e., 16 exposures) continue twisting the film wind knob until you hear the end of the film roll’s backing paper slip off the spool. You can now remove the film holder and process your film.

Exploring this manual mode of operation with the Pentax 645 represents more than just the elimination of battery power. It also reduces the size of the camera and lightens its overall weight. Granted, twisting the small film wind knob isn’t as glamorous as using a winding crank, but this manual conversion technique does give an all electronic camera a new lease on life when its lights go out.

Enjoy.

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