Here's my fixture design for the 50W MV miniature high bay. The box on top is a steel 6" X 6" X 4" Hubbell and the bucket is a 10 Quart galvanized steel pail about 11" in diameter. The bucket is quite large. I could actually fit a mogul base ED23.5 lamp inside this reflector! So I could make this 100W MV or 50-100W HPS as well. 150W HPS would fit but it might generate quite a bit of heat. I could also make this up to 100W PSMH with an HX ballast. Ballast enclosure might be a tight squeeze for a quad-tap CWA ballast like most PSMH ballasts are sold as.

Anyway, this is the RBJ, Relfecto-Bay Junior, the big brother to the Mini Reflecto-Bay, which is only for 35W HPS or incandescent lamps up to 100W. The fixture is just too small for anything larger. Would run too hot and no other ballast would fit.

But in this thing, it's a lot more flexible with the lamps that can be used.

This fixture hasn't been assembled yet. I just stacked the components for the pic. I'll probably paint the outside of the bucket but other than that, it will remain the same (I might even leave the bucket bare since most highbays have unpainted buckets). The handle of the pail will get removed during final assembly.

Everything here was purchased at Home Depot for around $35. I had a gift card so this fixture didn't really cost me anything.

My other mini highbay was constructed pretty crudely. I think this is a much better design. Higher quality components and larger so the components can "breathe". I'd imagine that, with such a small lamp mounted high up in a large bucket, this fixture will create a pretty small pool of light below it, but the pool should be pretty concentrated. I guess this fixture would thrive at a higher mounted height. An ED23.5 lamp would probably be more suitable for the optics though. This giant bucket is a bit overkill for a tiny E17 lamp, which is only about the size of an A19 incandescent.