Fujifilm Instax Wide 300 to Mamiya Press mount mod

How I modified an Instax Wide instant camera to mount a Mamiya Press medium format lens

If you follow me on Twitter or Instagram you’ll know that my latest weekend project was a modification of a broken Fujifilm Instax Wide 300 camera to mount Mamiya Press medium format lenses. Scroll down for a more detailed guide, or continue reading for some background on why this project came to be!

Also, if you enjoy reading about projects like this, come join us on the 3D-printed camera Discord! It’s an amazing place to hang out with like-minded photographers who love creating new cameras and modifying existing ones.

Stock Fujifilm Instax Wide 300

My favorite Polaroid instant film ever is FP-100c packfilm. That film was so good that it gave me the best instant camera results I’ve ever had, even in a $10 plastic piece-of-crap camera (in Dutch). But Fuijfilm, the sole remaining producer of packfilm after Polaroid’s original demise, discontinued production a few years ago. I’ve been looking for a replacement instant film with the same vibe for a while now and the only real option is Fujifilm’s Instax Wide film. It uses a very different chemistry than Polaroid’s packfilm but the final product has a somewhat similar size.

The only problem is that I dislike Fujifilm’s camera for it. The Instax Wide 300 does what it’s supposed to, but at the end of the day it’s still a glorified toy camera – even if it retails for $130. The image quality coming out of its plastic lens is unimpressive and the (complete lack of) controls limiting. Even compared to my $10 thrift store Polaroid, the Wide 300 is an underwhelming camera.

As it turns out, I’m not the only one who feels this is an issue. The desire to have more control while shooting Instax Wide inspired MiNT to design the InstantKon RF-70 camera, offering – in their own words – “the only WIDE format camera that offers full manual control – shutter speed, aperture, and focus.” 

MiNT InstantKon RF-70

On paper this is super cool, who wouldn’t want a manual instant rangefinder camera? Well, there’s a big downside to the RF-70… and that’s the $900 price tag.

So the more adventurous people on the internet are taking apart their Instax Wide 300s and installing higher-quality manual lenses, like this cool mod by JJ Lee. His mod does reveal some of the problems inherent in switching out the lens on a Wide by hand, as you’ll need to find a way to get the lens spaced at the right distance from the film to focus properly, which involves a lot of trial and error, and then hope nothing ever moves or shifts.

Fujifilm Instax Wide 300 x Schneider-Kreuznach lens mod by JJ Lee

A more elegant solution is the one by Max Wanderlush, who sells modified Instax Wide cameras that mount Mamiya Press or Polaroid 600SE lenses. The Mamiya Press line of medium format lenses is a favorite in the 3D-printed camera scene, combining great image quality with a built-in shutter module that you can use without electronics. The Polaroid 600SE was a modified Mamiya Press camera that Mamiya designed for Polaroid with similar characteristics – but a different mount. Both the Mamiya Press and the Polaroid 600SE line cover a range of focal lengths, so having a lens mount on the camera instead of a permanently installed lens gives you much more flexibility down the line. And because the 3D-printed mount has been designed to give you the perfect distance from film to lens there’s no risk of getting that measurement wrong.

Fujifilm Instax Wide 300 mod mk4 by MaxWanderlush

Because the Mamiya/Polaroid lenses are fully manual and don’t interface with any of the electronics in the camera, Max guts the Wide’s unnecessary internals, retaining only the development rollers, motor, shutter release button and batteries.

To take a picture with this camera you have to manually set focus, shutter-speed and aperture, cock the shutter, and release it – all on the lens. Then you press the rewired button on the camera to eject the frame, which runs your photo through the rollers and starts the instant development process. To make this whole process easier Max’s more advanced cameras also have an integrated shutter release cable and laser rangefinder.

You can find some nice shots using Max’s camera on Instagram with the hashtag #mpwide300.

Max’s 3D-printed Mamiya Press to Instax Wide 300 Adapter

But what if you’re more the DIY type? Max has you covered: you can also just buy the mount adapter and modify your camera yourself. Which is exactly what I decided to!

How to mod your Instax Wide 300

If you’re looking to make your own modified Instax Wide 300, this is where the project starts. To begin with, check out this video by Max for an idea of the entire process. You’ll refer to this video A LOT while you’re building the camera.

On eBay I purchased a broken Instax Wide 300 with a broken lens that was sold as-is, for parts. Since I was going to gut the camera the lens was no problem and it only cost 10 euros. I already had a Mamiya Press 100mm f/3.5 lens for another 3D-printed camera project – a Goodman ZONE, blog about that coming soon – that I could swap between cameras. And now I had Max’s 3D-printed Mamiya Press adapter.

Taking apart my Wide 300

While the video is very good and guides you through all the important steps, Max improved the process in the past few months after recording that video so it’s very important to read the project page entirely before starting. The most important changes:

  • The video shows you how to wire a manual ejection cycle – where you keep the button pressed while the frame is being ejected – but you can now change that to a one-press ejection cycle like the camera originally had. This way you only have to press the button once and the frame will eject automatically. If you want this one-press mod make sure NOT to rip out the orange wires when the video tells you to, you’ll need those.
  • The video takes you through a light-sealing process involving lots of gaffer tape and foam. But if you won’t be using the Mamiya Press 100mm f/2.8, 127mm f/4.7, or Polaroid 600SE 127mm f/4.7 you have a more secure option that retains the original internal light cone instead. I don’t have these lenses nor am I planning on buying them, so I opted for this method.
  • In the video the 3D-printed mount is locked into place using superglue and light-sealed with gaffer tape. A superior light-sealing method is using Sugru silicone rubber.

So let’s get started! Follow Max’s video from 00:00 to 04:12. At this point you have your camera mostly disassembled and are getting ready to remove the electronics. This is the perfect time to read the one-press ejection cycle guide again to make sure you know which wires you’ll need to keep. Keep following the video from 04:12 to 4:53 to remove the main board.

Please note that the big black cylinder hidden in the camera grip is the capacitor that powers the flash; make sure you ALWAYS take care around these things and never, ever touch a cap’s terminals. I haven’t done the math on this particular capacitor, but as a rule of thumb I was taught to assume any big cap can potentially hold enough charge to kill you, or at the very least hurt a LOT.

Back to the video! From 04:53 to 05:49 Max covers the removal of the lens assembly and the internal light cone. The video doesn’t cover reusing the internal cone and instead light-seals the external body. But the cone will give you the same level of light-sealing the camera originally had – read up on the procedure (steps 1 – 6) here – so that’s the way I’m going. Follow the written instructions: pop the lens assembly out of the internal cone by pushing the pegs out of their channels. Once the lens itself is out, you’ll still have part of the rotating lens mechanism stuck in the cone. Don’t worry, they come out easily when you trim the cone down. I tried to do this neatly with a Dremel first, but it took way too long, so in the end I just used a saw and sanded the resulting rough edges with some sandpaper.

‘Trimming’ off the internal light cone

That should cover steps 1 to 3. We’ll get back to installing the cone, and the remaining steps 4 to 6, later.

Keep going from 05:49 to 07:27. From 07:27 to 12:20 Max covers rewiring the camera. Since I’m going for one-press ejection cycle mod, the information on his site overrides what he tells you here in the video. Most importantly, at 10:06 he tells you to rip out the two orange wires. DO NOT DO THIS. They go to a very important switch.

The one-press ejection cycle mod is built around this switch that the original camera electronics used to sense when the ejection mechanism had run through a single cycle. But in this mod, instead of using the switch as an input for the electronics, we’re going to use it to directly power the motor while the cycle is running and cut that power when it’s done.

If you wire up the camera like in the original video, pressing the shutter release button will power the motor but letting go will cut power. That’s why Max says you have to hold the button down and learn to time the 5-second-cycle perfectly. But when you’re using the one-press mod, the switch with the orange wires will engage once the ejection mechanism starts running. When you let go of the button, the power still runs through that switch and keeps the system going. The switch then disengages when the ejection cycle has run, cutting power to the motor at just the right moment. It’s an amazingly simple and inventive way to get the desired behavior.

Theoretically, that is. I you were to wire this mod up without any other changes the motor would start running indefinitely once you press the shutter release button. That’s because once a cycle is done the switch gets turned off and the motor cuts out… but the inertia of the system keeps the gears running just far enough for the switch to engage again, sending power back to the motor. This will keep going forever, or at least until you pop the batteries out. We need to modify the system so the switch stays off.

This is where the work on the gears in Max’s article comes in. I lifted a pic from his site to illustrate this: you want to modify the gear circled in blue because that’s the one that trips the switch. There’s a channel that the switch ‘falls into’ to signal the end of the cycle. To make sure the switch doesn’t get engaged again too soon, it needs to be extended counter-clockwise by about 4 to 5 mm. I used a Dremel for this, and I really don’t know if you could do this with any other tool. Once you’ve got the channel extended, wire everything up like Max explains in the article, install batteries, and hit the button. If you got it right the motor will stop after a single ejection cycle. If it keeps running, it means you haven’t dremeled far enough yet and the switch still gets engaged. Pull it apart again and give it a bit more Dremel.

Back to the video. Keep going for the bits at 12:46 to 13:52. From 13:52 to 14:41 Max covers the trimmed protrusions and foam that correspond to step 7 (and partly 8 and 9). But because we’re reusing the internal light cone, we skip these steps. The next parts from 14:41 on are steps 5 and 6. These steps are optional when using the cone, but it’s good practice to use tape to cover obvious light-leak sources like the flash window, just in case. Light leaks are the worst part of any camera modification project and you have easy access now.

From 15:59 onwards you’ll start reassembling the camera! We’re in the home stretch now. The bit from 16:55 to 17:52 covers steps 8 and 9 which we’re also going to skip. Instead of doing the whole bit with the foam, we’re going to install the internal light cone we trimmed down. Put it back in place with its original 3 screws. Keep going from 17:52 to 20:18 and the camera itself is reassembled again!

Now we just have to install the Mamiya Press adapter mount, which Max covers from 20:18 on. He also talks at 20:35 about how to mount lenses with a backplate, but those are the models that we can no longer use because we’re using the internal light cone. From 21:50 to 23:05 Max superglues the adapter into place. I used regular Loctite superglue which seemed to work just fine. The last step from 23:05 to 24:09 goes over light-sealing the adapter with black gaffer tape – but this gets replaced by the directions in step 4, and we light-seal with Sugru instead. Now once the Sugru dries… you’re really done!

Now this is the part where I ran into a little problem. The Press adapter uses an M2 captive nut and set-screw to lock in your lens and it turns out I only have M3 sized nuts and screws. No worries – I ordered some to install later, and in the meantime 3 strips of tactically applied duct tape will keep the lens in place.

Duct tape fixes everything

Then came the moment of truth – popped in a pack of Instax Wide film and ejected the darkslide. I used a lightmeter app on my smartphone to meter the scene, setting the ISO to 800 for Instax film. Set the lens accordingly, cocked the shutter, fired it, and pressed the rewired ejection button.

Nailed it

Not too bad right?

After this first successful shot we took the camera on a quick walk through Utrecht. I won’t bore you with all of the test pics, but we have a few shots now that definitely prove this setup to me. We’re going to have a LOT of fun with this camera.

Pretty cool, right? If you’ve enjoyed reading this you really need to come over and join the discussion on the 3D-printed camera Discord! Hang out with like-minded photographers who love creating new cameras and modifying existing ones.

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