Printed Reduction Rings, Diffusors, Warming Filters

I've been making various reduction rings for Retra, HF-1, and Atom strobes for a couple of years now. Not long ago I tried my hand as making a warming 4500k filter as well. But instead of printing it I resorted to traditional arts and crafts. I used epoxy resin to stick gel filters to acrylic disks and then inserted them into the reduction rings to mount on the strobes. This worked ok, but the filters didn't have a diffusor element, and they required a lot of supplies to buy, prepare, and assemble. The results were okay but not great.

Older design:

Yesterday I decided to take another crack at the project, and ended up doing a revamp of the Retra Reduction Rings and I created 100% 3d printed diffusors and warming filters. The desktop tests look pretty good, and I will test dive them tomorrow to see how they hold up.

I also made the filters for the HF-1 and Atom reduction rings as well, which are a slightly smaller diameter.

Updated Retra Reduction Rings:

The Reduction Rings are a three part set with a Base 88mm wide angle ring, a 60mm macro ring slots to the base, and finally a 38mm super macro ring. The Base ring can accommodate an optional diffusor/warming-filter insert. I remodeled the Base and 60mm rings as part of this new project.

New design with white and warming filters.

So far I have made a fairly traditional while diffusor and a yellow one that is a pretty good match for the 4500k warming filters from Retra and Backscatter. They were made sandwiching two very thins layers of Transparent PETG and White or Yellow PETG. Two layers of white, or a combo of white and yellow was too opaque and lost too much light. So making one layer from Transparent PETG was a good discovery.

I did some bench tests with a bunch of filters on a Retra Maxi at 1/200s, f11, iso64, @ 38mm. 30 cm range. The Retra power level was mostly between -2 and -1 and tuned to deliver a consistent exposure. My Nikon Z8 was set to manual white balance of 4500 kelvin. No color corrections were applied after importing these images in to Lightroom.

Warming filters are most useful for wide angle and ambient light backgrounds, but you can at least see the relative performance.

Shown below are the:

1. Retra Maxi 6500k native

2. Retra Wide Angle Warming Filter 4500k

3. Backscatter HF-1 White diffusor

4. Backscatter HF-1 4500k warming filter

5. My 4500k gel filter

6. My 3d printed warming filter

7. My 3d printed white diffusor

I'll dive the white diffusors tomorrow for a deep, dark, six-gill shark excursion. Not the best showcase but I'll see if the printed diffusors hold up at a minimum. Hopefully I'll have some new shark photos to share.