Kinematic Photo Scanning Rig

Materials: PETG, Steel

Processes: CAD Design, 3D Printing

Tools: Fusion 360, Adobe Lightroom

Resources

About: This whole project started when I was recently tempted back into the world of film photography. Quickly realizing that getting film processed and scanned was prohibitively expensive, I decided to spend even more time and money complicating the process. This consisted of entering into the world of film development and scanning. Scanning is the topic of conversation here. 

When you get film processed and scanned at a shop, you get some negatives and TIFF files of ranging quality. There is some, but not a ton in the way of latitude in editing a TIFF file. Enter Negative Lab Pro. This software allows you to use the DSLR or mirrorless camera you already own to shoot RAW files of negatives and process them all the way from negative inversion to final export in Lightroom, all in RAW. 

Check out the video by Matt Day, linked above, for the inspiration for this build. Essentially you need to position a camera perpendicular to a plane that holds a negative and allows for back lighting. I have been working with some optics at work, am in love with kinematic mirror and optics mounts, and wanted to incorporate a similar design into this project. 

Design: I bought an old cast iron drop indicator stand from one of/the last watch manufacturers in Waltham, MA years ago. I had planned to turn it into a watchmaking tool for pressing hands or similar functions. That didn't happen and this was a perfect project to use it in. The camera and negative plate need to be quite rigid and resist vibration. Nothing like cast iron for the task. 

The general idea was to be able to level the camera to gravity and then be able to similarly level the plate. This way you could use the setup regardless of how level the table you're working from is. For the camera I used a "tripod level base" which is much more rigid in this configuration than a traditional ball head. 

The actual platform is made from 2 general components. One attaches to the upright and the other is supported on three points (making a plane). Two points are adjustable with screws and the third is a ball to pivot. 

The light passes through a hole that allows enough room for 35mm as well as 120 up to 6x9. 

Manufacture: The gross majority was COTS, owned, or 3D printed. I should say it all was. If someone was to want to make something similar you could with minor modifications to account for vertical shaft diameter or whatever other variations are necessary. The only change I would make would be to machine the plate that the negative sits on. 3D printing doesn't make flat plates very ... flat. I think this should do for now. 

Fusion360 File - all of the COTS parts are from McMaster-Carr and their P/Ns live in the F3D file. 

Conclusion: I am very happy with how everything turned out so far. I've scanned in some 6x6 negatives with great results. Photos below. 

A few points to consider. 

Keeping your film flat is extremely important. I'm currently having issues with film, curled lengthwise, not laying flat in the DitigaLiza. Photo below. With macro images at this distance, you have an extremely shallow DOF. Even slight bow in the film can lead to certain areas being out of focus. 

The lens you use matters. For larger negatives like 120 you don't need a full macro (1:1) lens even on a crop sensor camera. But for 35mm, a good dedicated macro lens is probably best. These can be had for cheap if you have a mirrorless camera that will adapt vintage macro lenses well. 

 

The light source is critical in getting the full spectrum of light registered in your digital photo. This has not been a problem for the black and white work I have scanned so far. With some upcoming color work, I might consider going to a light source with a higher CRI value. For now the iPad works fine. 

 

You can also scan negatives at high magnification and stitch them together in Photoshop's Adobe Photo RAW. If you have enough magnification, without optical loss, you can create some massive RAW files. From there you work through the same Lightroom Negative Lab Pro plugin. 
 

Enough blab. Here are some photos. The last is a photo fully processed. It turned out with a resolution of 6855x6855 with 4 composite photos. 

© 2020 Parker Musselman