Hi Don,
Thanks for the tips, the differences can be quite subtle at times and it's nice to get this kind of knowledge to help make the learning curve not quite so steep.
I've swapped the 46" brolly for a much more manageable 36" item. Whilst it's a lot more practical, I'm now suffering from light spill around the top edge of the brolly. As you can see in the attached, the head of the gun mounted on its bracket is quite a bit offset from the centre line of the brolly. With the bigger 46" brolly, this didn't really matter so much as there was more than enough area to capture all the light output. With the smaller item, I'm finding I'm getting a less even light distribution and a noticeable dead patch in the pool of light as the gun head casts its own shadow.
Following your earlier suggestion (via email), I've been experimenting with the zoom setting on the head. With the 46" I found the 18mm setting on the flash to be ideal, on the 36" I find this is too big a spread and I'm losing a lot of light spilling over the top. If I retract the wide angle diffuser and set the zoom to 24mm it's about as good as I can get it. Going to a narrower beam than 36mm results in very uneven illumination but a lot of power in a particular pool - which could be useful.
Sassan commented on my pocket watch shot
http://www.worldphotographyforum.com...=500&ppuser=34
that a touch more DoF would be better, I agree, but I'm rapidly running out of light at f/14 as I lose the light over the top of the brolly.
Any suggestions as to how this could be overcome? Without spending £500 on a studio head that is
Duncan