Great photo Salvatore. Would be interesting in seeing details of your DIY flash diffuser:-)
Thanks Brian. I looked at various youtube videos returned by a 'DIY flash diffuser' search, but most looked very cumbersome and fragile, fine in a studio but unlikely to survive long in my camera bag on a hike. But it did give me some ideas. This is what I came up with - it's very much a first attempt.
This is it so far. A white plastic container (originally containing Ovaltine), with the neck cut off, and half covered in aluminium foil.
It fits over the flash head. As the (round) plastic has to be bent a bit to fit over the (rectangular) flash head, it stays put without any assistance. It can be packed away pushed back down the flash and still fits inside the faux-velvet drawstring bag.
The flash head is far too high, pointing in the wrong direction considering at 1:1 the subject is only about 70 mm from the front element.
The idea of the foil is to bounce light downwards. I'm not sure how effective it is - more experimentation required. I think the next step is to mount the flash next to the lens somehow. I've got various cables and brackets but don't want to make the ensemble too unwieldy. Also I've an idea to attach the diffuser to the end of the lens (almost like a petal lens hood with diffuser one side and reflector on the other, if you see what I mean).
Anyway, the results. The flash allows me to use an aperture of about f/14 to f/20. The shadows seem to be softened compared to bare flash, although there are bright reflections off any shiny bits of anatomy (but that happens with bright sunlight as well).
This beastie was approx. 3-4 mm long (tip of head to end of wings)