Starship Light Tunnel Diffuser

I, as have most of us Focus Stackers or just plain macro shooters, have wrestled with lighting and light diffusion at one time or another. Well, I too have a studio full of gadgets that attempted to solve that problem. They all seemed to be way to large and in the way. The best one up until now was using a Styrofoam cup as a diffuser. The only problem with that was that it is too good at diffusing. To get good definition/contrast and the feel of 3D you have to run your lights at a lower power on one side. Well the cup just blasts the subject with strong all around light no matter what you do, therefore lower contrast.

In my search for a solution I was watching one of Allan Walls YouTube videos and low and behold he had a small plastic tray that he attached some tracing paper in a arch over the subject. Wow that was what I was looking for, well almost. As usual I took a simple idea and turned it into a “Starship”, no I mean literally, it looks like a Starship. I, as have most of us Focus Stackers or just plain macro shooters, have wrestled with lighting and light diffusion at one time or another. Well, I too have a studio full of gadgets that attempted to solve that problem. They all seemed to be way to large and in the way. The best one up until now was using a Styrofoam cup as a diffuser. The only problem with that was that it is too good at diffusing. To get good definition/contrast and the feel of 3D you have to run your lights at a lower power on one side. Well the cup just blasts the subject with strong all around light no matter what you do, therefore lower contrast.

The design is based on what I know about the art of light diffusion, which is not much.

1.     Multiple layers of diffusion material work best.

2.     The closer to the subject the diffusion material is the better the light wraps around the subject.

3.     I wanted clear space under the subject holder so I could work reflectors or lights under the subject.

4.     Easily mounted to various studio setups, simplest tripod mount to the most complicated focus stacking rig.

5.     Easily 3D printed.

Based on what little I knew I designed the diffuser to have two layers of easy to install and remove domed diffusion material separated by a ~7mm air gap. I designed it in two sizes 60mm clear inside, for smaller critters and 100mm clear inside for the larger critters. Remember you want to keep the diffusion material as close to the subject as possible without being in the picture.

After several designs I settled on the “Starship Light Tunnel” you see here.

I designed two sizes, one with 60mm clear inside and one with 100mm clear inside for bigger subjects.

3D printer

Polypropylene stress relieved sheet .03” thick that’s a min. of 24”W x 48L” with both side matte https://www.eplastics.com/PRONAT-03X24X47M-M.

Packing Foam from Walmart

Fun-Tak” by Loctite https://www.amazon.com/Loctite-Fun-Tak-Mounting-2-Ounce-1865809/dp/B018A3AG0W?pd_rd_w=wZaQ4&pf_rd_p=bb77d25e-38d7-4c74-a263-e922267edaaa&pf_rd_r=MJS2Q0CAWMZSCRHNNFPJ&pd_rd_r=da3ee1c7-dc47-46c0-aac3-971f4b0697c0&pd_rd_wg=Q26U6&pd_rd_i=B018A3AG0W&psc=1&ref_=pd_bap_d_rp_1_i

First step is to print the Starship diffuser holder using the attached .stl files. I keep both sizes around so I can easily change the clear space as needed.

You then need to acquire a sheet of “Polypropylene stress relieved sheet .03” thick that’s a min. of 24”W x 48L” with both side matte. I get mine from ePlastics on the internet at: https://www.eplastics.com/PRONAT-03X24X47M-M.

For the 60mm tunnel cut one strip from the Polypropylene sheet 160mm wide. Divide that strip into pieces 175mm long and another 200mm long. For the 100mm tunnel cut one strip from the Polypropylene sheet 160mm wide. Divide that strip into pieces 250mm long and another 275mm long. 

Using spray glue apply one layer of Packing Foam to one side of each diffuser. Then along the 160mm edge remove 7mm of foam to fit into the slots on the “Starship Light Tunnel” mount.

To hold the subject I use a product called “Fun-Tak” by Loctite, you can get it here: https://www.amazon.com/Loctite-Fun-Tak-Mounting-2-Ounce-1865809/dp/B018A3AG0W?pd_rd_w=wZaQ4&pf_rd_p=bb77d25e-38d7-4c74-a263-e922267edaaa&pf_rd_r=MJS2Q0CAWMZSCRHNNFPJ&pd_rd_r=da3ee1c7-dc47-46c0-aac3-971f4b0697c0&pd_rd_wg=Q26U6&pd_rd_i=B018A3AG0W&psc=1&ref_=pd_bap_d_rp_1_i

Take a glob and apply it to the mounting pad on the front of the mount. Stick the mounting pin in the glob and squeeze tight.

Insert the diffusers into the slots on the mount and setup your lights.

1.     As you can see above there are many ways to use the “Starship Light Tunnel” from the simplest by just mounting it to a sm. tripod .

2.     Or for better control attaching it to a inexpensive “Lab Jack Scissor Stand “ https://www.amazon.com/WISAMIC-Scissor-Platform-Stainless-Laboratory/dp/B0836GFJQC/ref=dp_prsubs_1?pd_rd_i=B0836GFJQC&psc=1  

3.     By adding a inexpensive focusing rail for cross alignment https://www.amazon.com/EXMAX-Focusing-Close-up-ShootingCompatible/dp/B012SLQU2A/ref=sr_1_15?crid=2OMYEF5JMFVYB&keywords=focusing+rail&qid=1644513490&sprefix=focusing+rail%2Caps%2C153&sr=8you get much better control.

4.    Or attaching to a complex Focus Stacking rig.