Quenox Parabolic Umbrella vs. Big Octadome

I made myself a nice christmas present: a Quenox Parabolic Silver Umbrella - mine is 180cm and came used and super cheap via the bay. It it not exactly a parabolic umbrella like the Para 88 and thus not an ultra-versatile adaptable light shaping tool, that you can use outside, because ...well... you just can´t use the Quenox outside. Or anywhere near a window, for that matter. It is a huge umbrella.

But due to its shape and depending on the placement of the flash head you can produce a VERY effective beam of VERY nice light.

I had taken it to someone else´s studio where I found a large Octadome. Now, that´s a first test: compare the big brollie against the stripped dome. And guess what?

a Saturn V rocket as seen during take-off from below.

Although the Quenox seems to be the much, much harder reflector it is the one that casts NO shadow at this distance! Maybe I found a sweet spot? Maybe I was just the right distance from the background? Let´s turn around and have a look at the paper

Here´s my arm. The Octa is now behind me to my right and the Umbrella to the left (they are so huge that I CAN stand between them, although they touch. Their respective middle axes are 1,5m apart.
You can clearly see that the Octa throws a shadow of me, my arm, my camera and the on-camera flash which I used to trigger the studio strobes.

Surprisingly, the stripped Octa is quite harsh, given its size (please don´t judge skin tones, shadow rendering or anything. The two silver monsters cancel each other out on my arm). Without diffusers on, it should act like a giant wide angle bowl. Obviously, it´s the bare bulb blasting through the middle that makes it so hard. Hm, might try that naked Octa as ...let´s call it... ULTRADISH!

Check out the first picture again. Both heads are at the same power setting. But the umbrella is so effective that it seems just as bright as the bare bulb in the Octa. Giant silver disc? Nice! Very nice! Good thing to have that off your wish list ;-) Guess I´ll blast the models on the next test shoot with that beast...

BY THE WAY, holding out your fist in front of you is the professional way of checking the quality of the light. Your thumb represents the subject´s nose. This gives you a rough first impression of how and where to place your subjects in front of your camera regarding highlights and shadows.