No problem kaliff
The strobe i upgraded to was a sea&sea ys-90auto. I was a quite dissapointed with it on the first day in Sharm, as all it would give was a pathetic blip of light, however after a bit of fiddling and the help of a waterproof band-aid over the 'auto-sensor' i found that it worked much better giving plentiful amounts of light. I should have listened to this board and gone with the ys-90dx instead. Saying that though i am satisfied with it (for now).
I have the Epoque WAL, it screws straight onto the PT-018 housing, no adaptor required, there is no vignetting and minimal errr..chromatic abberation? if thats the phrase.
+ points:
1. Allows you to get closer to the subject for the same shot (quite a lot closer i was surprised), therefore having less water between lens and subject which means less suspended particles and less backscatter. Makes for clearer photos.
2. Camera seems to find it easier to focus, i definitely had very few out of focus shots compared to photos without WAL.
3. I think they may increase the depth of field of the photos.
- points
1. Have to ensure your strobe has adequate degree of coverage to allow for the wider view of the lens. I think the DS-150 may struggle with a WAL. You would have to check the specs of the DS-150.
2. Difficult to do macro shots, so may have to detach whilst underwater. Not difficult, but make sure it is leashed to your camera!
In all, well worth getting a wide angle lens. Looks mighty impressive to new divers too!