Kowa 1.6 Extender

[Rackseekers]

I was wondering if anyone has had any field experience with using the 1.6 extender on a Kowa Spotter? I'm assuming the image quality would suffer a bit, however, was wondering if it would be worth using. I Currently have a Kowa 884 and use it to diascope. I've been debating trying to upgrade to the 99, but the extra size and weight is the main draw back. I do a lot of backpack Couse hunts so I get the optical quality just didn't know if the extender would be a reasonable/usable option.

Thanks in advance for the help.