Strobe performance of Sea and Sea YS-D2 120 degrees vs Inon Z240

I have been looking at a new strobe to replace my Inon Z240s specifically for wide angle and I am not completely bought into the dome shape of the Z330 mostly for practical reasons I would prefer a semiflat port

Looking at various test this comparison on backscatter looks pretty interesting

If I look at this table and ignore the guide number assuming the measurements are correct relative to each other I can see that the Sea and Sea YS-D2 albeit having less power than the Inon has a more homogenous light beam at the edges

What is even more interesting is when looking at this other chart without diffuser and compare with a 160 round bulb of the DS 161

The graph looks identical to the sea and sea with the 100 diffuser

So considering that at the end a 160W bulb is what it is and broadly is a GN=24 my conclusion is that unless there is some magic in the reflector design (and it may as well be with seacam and retra strobes) there is no point getting a circular bulb strobe and the Sea and Sea YS-D2 looks pretty good

However I also see in this graph that my Z240 actually are the best on this comparison in terms of light fall off with a drop of 1 and 2/3 stops between centre and 90 degrees

I have been pondering about getting an YS-D2 and using a 120 diffuser to have a more uniform beam however doing the maths it looks like once I apply the 120 diffuser and have a loss of 1 1/3 of a stop the power increase is very marginal to none compared to my Inons

From the theory here I do not see any compelling argument to change my Inon with the Sea and Sea YS-D2 and as the Z330 give me issues with ergonomics I see to reason for that either

Currently the only strobe that look as they could be interesting are the not yet released Retra Pro

I wonder if there is any real life comparison YS-D2 vs Z240?

So considering that at the end a 160W bulb is what it is and broadly is a GN=24 my conclusion is that unless there is some magic in the reflector design (and it may as well be with seacam and retra strobes) there is no point getting a circular bulb strobe and the Sea and Sea YS-D2 looks pretty good

I had the opportunity to measure the Ikelite 161 and Seacam 150 with a light meter in a studio to find out that the Ikelite produces about 0.5 F-stop less power in the center and a about 1 F-stop less at approx. 45º angle (90º spread). Their white reflector is eating away too much light compared to the metalled Seacam one. It's just that the reflective surface of a metalled part will be better than a white (biege) one.

Interesting data, the Z-330 diffusers are termed soft and don't spread the light according to INON, just "Soften" it, though it does lose more than the advertised 0.3 stop. Be interesting to see how the Z 330 performs with a more conventional diffuser??

In my hands at least with the same type of experiment, it is very difficult to tell the YSd2 from the Z240 especially at the edges.

Bill