This is a series of plates and a camera hood for scanning 120mm medium format negatives using a digital camera and a light table.  Originally designed for a Canon SX40HS point-and-shoot camera, I've included an SCAD file for the lens hood that can be customized for almost any digital camera.

Bottom plate requires the use of a sheet of 0.093" thick acrylic, I got mine from Home Depot for less than $5.

Using the SX40 manual mode the focus is set to about 1.5 inches, ISO 100, aperture at 2.8. I adjust exposure by changing shutter speed. I also use the self timer at 2 seconds to be sure I do not shake the camera when scanning. The attached photos were scanned in this manner. The original scans are much better quality than seen here, you can easily make out the film grain - a better camera = better results!

I printed the infill on my top plate too low in the photo, so make sure you print with enough that the top layers survive. Make sure to use a filament that is as opaque as possible, and ideally has a matte finish (or scuff it up with sandpaper).

What To Print:

• 6x9 Bottom Plate
• Top plate with dimensions that match your negative
• Lens Hood (suitable for your camera)

Needed to complete:

• Light table
• Sheet of 0.093" thick acrylic (I got mine from Home Depot for less than $5.)
• Digital camera with manual mode (focus and exposure)

How To Assemble:

Print the 6x9 bottom plate and cut a piece of acrylic 61.5mm wide and 110mm long. The acrylic is glued into the recess on the top of the bottom plate. You may need to sand the sides of the acrylic to fit depending on your tolerances. I glued mine in with Goop.

I haven't tried it yet, but it may be wise to glue a thin piece of black felt on the bottom of the top plates to prevent scratching the negatives.

How To Use:

• Place the bottom plate directly on your light table.
• Place the negative to be scanned on the bottom plate
• Place the top that matches the negative dimensions on top of the negative and bottom plate. The corners on the bottom plate will meet up with the notches on the top plate to ensure the correct position.
• Place the lens hood on the top plate. The lens hood will fit around the rectangle on the top plate to ensure the correct position.
• Place your camera onto the lens hood.
• Adjust focus, exposure, and shoot!
• Use your favorite image editing software to invert colors and make corrections.
• Enjoy your high-res digital scan!

Notes:

While the bottom plates are standard, you will need to create a lens hood that matches the lens diameter and depth requirements for your camera.  This is done via the SCAD file using the latest version of OpenSCAD.  Enable the customizer, or just edit the variables directly.