Topic: INSTAFRANKENROID - Hacking a Polaroid land camera for Instax.

[rotarysmp]

Hello Filmwasters,

I have been a member here for years, but with long periods of inactivity as I tend to cycle through my hobbies (Photography, guitar, machining).

My daughter bought an Instax 210 while travelling, and has been using it a lot. This bumped my enthusiasm for a project which has been on the back burner for a while. I hacked a 100 Automatic Land camera with a Mamiya 105 f3.5 from a TLR a few years ago, and then the last call for pack film followed shortly after. Having consumed all but one remaining box of FP-3000B, that camera has lurked in the deepest recess of the closet, till now.

There are plenty of bodged up Instax wides gaffer taped to Land cameras and Pathfinders, but I hadn't seen much information on optimising such modifications. The aim being to couple the excellent Zeiss combined range/viewfinder accurately to a fast and sharp lens with manual aperture and shutter control and a flash shoe.

Here is the first episode of my attempt to document such an Instafrankenroid.
https://youtu.be/UHYeu-3LmRk

In an idea world, hacking Instax wide to the original film gate of a Polaroid 180/190, while keeping the rangefinder system would be the holy grail.As you can see, the design features central to both designs are unfortunately in direct conflict in the upper focus arm/development roller area.
Mark

[Francois]

Conversions are definitely never easy.
I discovered that when I converted a colorpack to use full size 4x5 sheet film. Took me a lot of planning and about a week of work and problem solving to manage to create something that works.

[rotarysmp]

Hi Francois. I have been be agonising over the unsolvable compromises of this conversion for a couple of years. Figured there was no way I could optimise it in one go, so it was better to get stuck in a hack together a prototype and see how my ideas pan out.

I also have 110A + 900 Rangefinder to 4x5 half finished.
Mark

[cs1]

That's rather impressive, Mark! I hope that you'll succeed. I'm thinking about buying an old polaroid back for my Bronica SQ-A and hacking an Instax Square mechanism on it. Looking at your video inspires me to actually try getting the parts and giving it a go.

[Francois]

One thing I never figured out is why nobody ever manufactured a cheap 4x5 compatible Instax film back? That would make things so easy.
I do know that the Lomo Belair had an optional instant back, but at close to 400$ for a plastic hand cranked gadget, it was pretty much out of price for anybody.

[rotarysmp]

I have nearly finished my hand cranked roller drive. I should have been more careful disassembling the Instax 100, as I decided too rashly to dump the electric drive motor, and drive train. Need to get another one and take a more careful look at what could be done to realign the motor and make it fit better.

I agree. There may not be a huge market, but I'm also surprised that no one has built one, or that Lomography hasn't run another production run of Belair backs. However, it is not that trivial to make an instax back which could maintain the exising film plane. If you can't do that, it become a whole lot less attactive.

On any instant film system, you are going to have one roller in front of the film plane. On pack film, because it pulls horizontally, that roller is already quite a distance from the camera center line, so it is easy to have it overhang the side of the camera.
With instax pulling vertically, the rollers are much closer in.

Bascially, you need to move the rollers further away, and have a longer push out system. Okay I guess that is trivial, but you need a complete redesign.
Mark

[rotarysmp]

I just saw another Instax back on offer which I wasn't familiar with.

http://coyotecameraworks.com/instaxbackrb67/
https://www.youtube.com/watch?v=pn0r-CUWuCs

If you look closely, the distance between the dark slide and the film ejection slot is minimal.  The RB67 is a good candidate, as you can remove the revolvoing back, and this gains the extra cm you need to keep the original film plane.


I wonder what their film rollers look like? I also wonder how much you can reduce the roller diameter and still have effective film ejection. The Fuji wide rollers are textured to grip the print, as opposed to the polaroid rolers which are smooth, as they dont have to drive film out (it is pulled).

Another design data point is this video.
https://www.youtube.com/watch?v=rg2DKQT-44Y
Where the guy demonstrates that the Lomography LC-A+ back does not eject reliably.
Mark

[rotarysmp]

I just uploaded the second part of my Instafrankenroid hack.
https://www.youtube.com/watch?v=0RuOGkFgX2I

Mark

[rotarysmp]

This is what the Instafrankenroid looks like so far. I was hoping to start testing it, but the film plane is about 7.5mm too far back to make infinity focus, so a new lens board will also be required.

[Francois]

You might be able to get away with the current setup by adding a diverging lens.
Think of the camera as having myopia

[rotarysmp]

I guess that is a possibility, but the chances of finding a diverging lens in 43mm filter size which matches to a 105mm lens to move it 7.5mm would seem pretty remote. I was surprised how far off the focal plane is. My expectation would have been closer to 3-5mm off. Designing  and milling up a new lens standard shouldn't be too difficult though.

Here is the third episode of this hack...
https://youtu.be/WBWwJdtoIPo
Mark

[Francois]

There are actually ways to calculate how strong the lens needs to be.
When I was running into problems with a build I thought of going to an optician and have them order and cut a lens just for that. But since I was building it on a shoestring budget, I opted for a serious hack job instead.

[rotarysmp]

What Francois said:

There are actually ways to calculate how strong the lens needs to be.
When I was running into problems with a build I thought of going to an optician and have them order and cut a lens just for that. But since I was building it on a shoestring budget, I opted for a serious hack job instead.

What Mark heard

a serious hack job

Now we are speaking the same language
Mark

[Francois]

 
I must admit that the sound of a Dremel is quite satisfying.

[rotarysmp]

I made some more progress on the Instafrankenroid. The new lens standard moves the focal plane to about the right place, and it now focuses on infinity. As expected the shorter focal length  (Mamiya 105mm instead of Polaroids 114mm) means that it front focuses at the closer range. For that I'll need to dive into the linkages and cam of the rane finder, but for now the camera seems pretty usable.

Here is the latest video update...
https://youtu.be/xgzRbOfX9Ao

Mark

[jojonas~]

Impressive work here, Mark! You really put that machining know how to good use on this

[Skorj]

Great stuff!
There's at least three Polaroid to Instax conversions here in the Articles section.
You might need to go back a few pages to find them though...

[rotarysmp]

After a year and a half of making blurry photos, becasue I forget to lean forward 13cm after focusing, it was time for a new rangefinder cam.

https://www.youtube.com/watch?v=UCQW5uKzdhM

...later...
This gentleman reached out through Youtube...
https://www.instagram.com/jianyi.su/
His workmanship is just excellent. He implemented all the ideas I had been thinking about for an Instafrankenroid. Brilliant.
Mark