Dee, following is a reply that I received from the manufacturer of the MXTender that you spoke of, the link which your provided. If I choose to go this route, using the MXTender with the MX5II, I'll let you know how it works.
Thanks for your help.
Andrea
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Dear Andrea,
Thank you for your email, and your question. Although I have not tested the MXTENDER with the MX-5II, I am almost certain it would work. From the looks of the MX-5II, it uses the same mount as the MX-10, which makes sense since it would allow Sea&Sea to use the YS-40's injection molds to manufacture the YS-20 strobe, saving them the huge cost of a new mold.
Naturally, I'd want to test it thoroughly, but I indeed think it would work fine.
Let me say that if you don't own a camera, I do NOT advise you to buy an MXTENDER and MX-5II. You could apply the $199.95 cost of the MXTENDER, plus that of the MX-5II and strobe, toward a better camera system. There are many choices available in the approximate price range of an MX-5II/YS-20 with MXTENDER, including digital systems.
If, however, you already own an MX-5II and are looking to solve its backscatter problem, then the MXTENDER may be a good choice for you. The alternative would be to sell the MX-5II, absorbing the loss you'd take, then step up to a higher system. It all comes down to your needs, wants, and finances.
Let me know if I may be of further assistance.
Most sincerely yours,
Greg Bunch
info@gbundersea.com
http://www.gbundersea.com