Can you shoot INSTAX in a Mamiya 7?

2023-10-07: Can you shoot INSTAX in a Mamiya 7?

Well, yes you can.  Here's how!

Mamiya 7 and INSTAX Mini 90

 

There are a few obstacles to tackle:
1. Mamiya 7 won't release the shutter with the film door closed without 120/220 film present.
And the frame counter must be wound to "1", which can't happen without film.
So how do we get around this?

I searched and found that the only option being used was to tape the undeveloped INSTAX photo in place over the frame opening, install a roll of film (or just the paper backing), close the back, and then wind to "1".  The tape was used because winding the 120 film would move the INSTAX photo out of alignment. I didn't really like this idea from a workflow perspective.

After some thought, I remembered that the Mamiya 7 will release the shutter if the back cover is open.  But we can't shoot with the back cover open or even cracked for obvious reasons.  So I removed the bottom cover and went exploring to find the micro switch that detects when the film door is open or closed.

Mamiya 7 with bottom cover removed

Under the bottom cover is a thin flexible metal wire that shorts across two pins when the door is closed.  With the door open, the metal wire doesn't make contact.
So the hack is to very simply unlatch the wire from the plastic hook!  This is a completely reversible modification.

2. Aligning the INSTAX Mini photo over the frame opening

This next challenge is not too difficult as the Mini film is just the right size, but there is a little wiggle room.

 

Remember that INSTAX exposes the image from the back side of the film, so be sure to orient the back side down towards the lens; the developed image side will face you, as shown in the above photo.  Practice in the light until you get the feel of it.

All of this must be done in complete darkness - either in a fully darkened room or a film changing bag (aka "dark bag").  I prefer the dark bag for convenience.

BEWARE of inexpensive dark bags on the Am*zon and other marketplaces!  I bought a cheap one, and it did not pass the flashlight test!  

I found that this Harrison bag, while expensive, to be truly dark.

Harrison Medium Film Change Bag

3. Developing the film

To get the correct exposure, I use a Sekonic light meter set to ISO 800 and then targeted to whatever aperture or shutter speed I want. 

After shooting your photo in the Mamiya 7, the INSTAX mini must be developed by spreading the chemicals from the packet evenly across the entire frame.  I already have a Fujifilm INSTAX Mini 90 camera perfectly suited for the task (and which I highly recommend for Mini format shooting).  So back to the dark bag with the Mamiya 7, the Mini 90, and an empty Mini cartridge.

Fujifilm INSTAX Mini 90 and empty Mini Cartridge

INSTAX Mini Film Cartridge

In the dark bag, you just have to transfer the exposed Mini film from the Mamiya 7 into the Mini cartridge (lift the flexible light flap out of the way), then into the Mini 90 camera, then close the door.  The Mini 90 will automatically eject the frame.

I tend to leave the ejected film in the complete darkness of the bag for a minute or so.

Is the time and effort worth the results?  I think so:

Portable Dark Room

Mamiya 7, N 43mm f/4.5 L, f/16@1/250

Mamiya 7, N 43mm f/4.5 L, f/22@1/500

Mamiya 7, N 150mm f/4.5 L, f/16@1/500

Mamiya 7, N 43mm f/4.5 L, f/22@1/500