Scale Focus 6x6

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kzphoto

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I love my Fuji GF670 for shooting squares, but there are times when I wish I could use a wider lens. Most of my photography is done in daylight, so I can scale focus and shoot at f/8 or f/11. Given these constraints I decided to make my own camera.

Idea: To make an scale focusing 6x6 camera with interchangeable lenses. The camera will work with hasselblad film backs and modern "digital" lenses. Widest lens: 35mm XL Apo Digitar. The benefit of working with a V-mount 6x6 back is future compatibility. If I decide to go MF digital, I may be able to shoot attach a CFV-39 or other V-mount back.

Items Needed:
-6x6 film back
-Camera Body
-Lens Helicoid(s)
-Lens(es)
-Lens Plate(s)
-Viewfinder Mount
-Viewfinder

The project thus far:
Camera and VF.jpg
Camera and VF2.jpg
Camera and VF3.jpg

Next will be to model the hooks / mounts for the film back, and the lens board for a 47mm lens.
 
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Something I have seen on Ebay-
http://www.ebay.com/itm/281089085411?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

The description mentions that the seller will provide a focusing scale if you give him a focal length.

Well, I have no experience of the product, and I don't know if it fits your project at all. I've given your idea some thought of my own which is why I had the focusing helicoid saved. My thinking doesn't involve a digital future or such, so practically gluing an old Graflex roll film back in place might do fine for me.
 
Dan,

I was planning on using that helicoid for the first lens, to see the quality of the machining. If it works out okay, I figure I'll make another lens or two with those focusing mounts.

The Schneider made focusing mounts aren't cheap at $400 or so, but they're meant to be quite good.
 
Nice ... a DIY ArcBody

a_Arcbody_Family.jpg
 
kzphoto said:
Dan,

I was planning on using that helicoid for the first lens, to see the quality of the machining. If it works out okay, I figure I'll make another lens or two with those focusing mounts.

The Schneider made focusing mounts aren't cheap at $400 or so, but they're meant to be quite good.
Click to expand...

It'd be good to hear how it works out.

Is the part you drew going to be CNC'd or 3-d printing? I assume CNC unless you have access to a very very nice 3-d printer.
 
Donald,

I just performed a CLA on a sorta gummy A12, and I realized that there's a little angular pawl that you can remove which will keep the back winding all the way through the roll. It means I have to look at the little window on the side inbetween exposures, but I'm not too concerned about it.
 
Dan Daniel said:
It'd be good to hear how it works out.

Is the part you drew going to be CNC'd or 3-d printing? I assume CNC unless you have access to a very very nice 3-d printer.
Click to expand...

Most likely CNC'd, but I don't have access to a CNC machine yet. There's a local company called "Tech Shop" that has lots of neat machines: laser cutters, water jets, cnc machines, mills, lathes, etc. You can buy a membership and schedule time on their machines. I think I might try to go the membership route. Alternatively, I have a few friends that operate high-end CNC machines. They've made a few things for me in the past, so I might be able to work with them on this project as well.

We'll see how it goes.
 
kzphoto said:
Most likely CNC'd, but I don't have access to a CNC machine yet. There's a local company called "Tech Shop" that has lots of neat machines: laser cutters, water jets, cnc machines, mills, lathes, etc. You can buy a membership and schedule time on their machines. I think I might try to go the membership route. Alternatively, I have a few friends that operate high-end CNC machines. They've made a few things for me in the past, so I might be able to work with them on this project as well.

We'll see how it goes.
Click to expand...

The parts I have seen from low-end 3-d printers basically suck. Horrible resolution. For optical/mechanical interfaces like a camera back you need flat and smooth surfaces, with maybe +/- .001" tolerances. If you can make the 'handle' section an add-on, your basic extruded shape is a pretty simple machining job. Maybe have the handle held on by screws?

Check the resolution of any 3-d printer you are thinking of using.
And check the material- I've seen some soft and gummy things presented as workable camera parts.
 
OK. Had to make a small revision to the model, since it was missing a dimension. 2nd version is just about complete but I need to send it off to get a prototype made. Anyone have any recommendations for CNC services? Everything online seems like it's made for engineers.
 
Sputnik Models in Redwood City-
http://www.sputnikmodels.com/

California Model & Design in San Francisco-
http://www.anyscale.com/

If either one won't handle it directly, they should be able to recommend someone. Both outfits are small hands-on operations. I know Alan Wolfe at Cal Model is into photography. I'm sure that Val at Sputnik will enjoy your project.

Another approach is stereo lithography. It's 'old' technology and should be pretty cheap these days. Resolution is an issue. I have no experience with this place but it should give you an idea of what is going on-
http://www.stereolithography.com/
 
Does the 35mm Digitar cover the full diagonal of 6x6?
This sounds like a cool project and it's something I'll do in the future but I'll be using a Graflex rollfilm back and will probably make the body out of some easily worked material like ABS. Thick walled plumbing fittings are optimal but not quite as pretty.
Definitely looking forward to seeing the finished product.

Phil Forrest
 
A friend was kind enough to 3d print a basic prototype for testing. simply to check shape / function. I'll post a photo this weekend once I have the print in-hand.
 
Fit looks good and my measurements are exact, although the 3d print warped as it dried down. . I need to figure out whether the magazine hooks should mount to the rear of the unit or the inside of the unit. Additionally, whether the magazine support should mount to the rear or the base.

Next up is a camera grip for the side of the unit and some detailed renderings of the first prototype.
 
Slight redesign to the VF holder, since it looked pretty fragile in the original design. Added a grip. Working with measurements from Schneider to build the model for the helical as well as the lens, to ensure proper FFD.

scale_focus_cam.jpg
 
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