What are the good softboxes for a small flash like a Canon Speedlite 430EX, for example?
Lastolite make an ezybox which is pretty "good" but it really depends on how you term "good". Do you want:
- Small when collapsed
- Durable and long-lasting
- Big (bigger the light source, the softer the light)
Have you also considered just using a shoot-through unbrella?
I've experimented with a lot of these devices and agree that the EzyBox is probably the best, but honestly I find that a flash bounced off the ceiling or wall with the little white card thing pulled up (or a business card taped on) is really the best bet for most scenarios. Check out my blog for a book review of On-Camera Flash to see some amazing stuff, and I've done many of those types of shots with less sophisticated flash attachments than Neil uses.
I also have interviewed some of the top photographers in the world on my blog and I find that many don't even bother with mods beyond the card trick I mention above. It's only the prosumers that obsess over flash modifiers