Strobe comparison - Sea & Sea YS-110 vs Inon Z240

Strobe comparison test

Inon Z240 versus Sea & Sea Ys-110


There are many strobe qualities important to the underwater photographer, such as coverage, color temp, size, recycle time and strength - usually measured with a guide number.


I suspected my Inon strobe was stronger than my S&S Ys110, but I wanted to test it to see exactly what the difference was.




underwater strobes

This is what my test showed:

  • With diffusers on, the Z240 is 1.5 stops stronger than the YS-110
  • With diffusers off, the Z240 is 1 stop stronger than the YS-110
  • The Inon .5 white diffuser reduced the strobe strength by (big surprise here) .5 stops.
  • The Sea & Sea diffuser reduced the strobe strength by 1 stop.


It's important to define the size of the area the strobe is lighting up. Strobes can be strong in the center, with falloff on the edges. 


In this test, I lit up an area about 12 inches wide. I might do some more tests lighting up a much larger area, similar to what I would take with my fisheye lens. I'd also like to test color temp.


Other differences:

  • Although the Inon is smaller, the difference is not that significant.
  • Both take 4AA batteries and have a similar color temperature. They are both considered "cooler" strobes. Strobes like Ikelite  Ds160 substrobe and Subtronic strobes are warmer strobes.
  • The Inon Z240 recycles much faster, 1.5 seconds vs 3 seconds. When they are on the same power, the difference is even greater. The new Ys-110a strobe recycles much faster, almost as fast as the Inon. I'm pretty sure the Ys-110a is the same strength as the Ys-110, but I'll test them soon to make sure.
  • The Sea & Sea strobe is generally less expensive, and has an easier to understand user manual.

Important update regarding the YS-110A


I recently tested the YS-110, YS-110A and Inon Z240. The YS-110A recycled much faster than the YS-110 and was 1 stop brighter. The Ys-110A is a close competitor to the Z240 in power and recycle time. I'll be putting up a full article on these tests soon. - Scott, February 3rd 2010


Further Reading

Inon Z240 review

Sea & Sea YS-110 review

Underwater strobe guide




Hi Scott, I have a Strobe of

Hi Scott, I have a Strobe of D-2000, and I also tested & compare with my friend's Sea & sea 110a, I do like my own Inon D-2000 with a STTL Flash connected with Optical cable foe my DC( not in Sycn Cord),
I try the ttl mode with 110a, which some body tell me it dosen't work ttl function with Optical cable connection, can you verify it?

Thanks for the review. What

Thanks for the review. What if your Inon Z 240 needs service? Must it go to japan?

Hi, I have a YS-110A strobe


I have a YS-110A strobe and I like it, I will buy a second one soon. Another great advantage of it, and the others Sea&Sea strobes is that the battery compartiment is isolated from the strobe itself: very difficult to flood it. Last year, in Lembeh, my friend flooded his Inon Z240... This problem is not unfrequent with the Inon... I find also the settings more simple and accessible on the Sea&Sea. My choice is definately the Sea&Sea !

Jacques-Yves PHELIPOT

Can't wait for it, I'm

Can't wait for it, I'm looking for the test report.

I have 2 Z240 strobes, and love them very much. My friend flooded the battery compartment during the trip last year, after soaked it in fresh water for a while, it still working !!!

Panot Laohabhan

Great info Scott. I looked at

Great info Scott. I looked at the Z240 and YS-110, and ended up with the Z240 and am very please with the results. My system is a Oly E420, Oly case, Heinrich bulkhead, 50mm Macro, and dual Z240's. I do wish/dream for a 100mm Macro though..