can anyone recommend a chimera type soft-box that can either go on the camera or carried next to the camera for mobile night street shots? And can this be powered by the camera or is a battery of some sort necessary? Thanks.
Chimera makes a little softbox for the Anton Bauer Ultralite which is available as either a tungsten or daylite source, but I also recomment the LitePanel on camera LED light which is daylight in balance but comes with tungsten correction gel in the kit. While this unit is pricey it creates a very nice "non-lit" look for night interviews on the street.
You might look and see if PhotoFlex makes a little Chimera clone for the Ultra (I don't know if they do, but they might).
I'm a big fan of PhotoFlex boxes, we use bunches of them (from the mid-sized ones to the gigantic). I've always found them to be as good or better made than the Chimeras and substantially less expensive.
If budgets aren't a major issue I would second the suggestion that Lite Panels are worth taking a look at. Lite Panels absoutely ROCK (but unfortunately, they also rock your wallet).
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