Flash zoom setting with softbox/umbrella etc


pschlute

Link Posted 11/06/2017 - 17:30
I will do some experimentation myself to find the best setting, but would be interested to hear what others who are using a diffuser such as softbox/unbrella/diffuser find are the best zoom settings to use on the flash unit.

I am thinking mainly of portrait style photography where the flash/diffuser will be quite close to the subject. So far I have intuitively used the widest setting with a softbox/umbrella.
Peter



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McGregNi

Link Posted 11/06/2017 - 20:16
Its a creative choice Peter, so there might be a purpose to different zoom settings ... however I have never found one apart from the widest setting (as you were thinking). The general aim is to fill the entire umbrella or softbox with light to the edges in order to create the widest spread and softest light when very close, without any hotspots.

A zoomed in flash head can create a brighter spot in the centre, which might be distracting on someone's face if it hits the cheek or forehead for example. I usually also set my flash head to the lowered 'macro' position in order to direct the beam towards the centre of the umbrella, again trying to create an even spread.

With a softbox then there is even less reason to zoom in I think .... they were not originally designed for use with Hotshoe Flashes, but rather studio bare bulb types, and the best result comes from light that reflects from all of the internal walls, top, bottom and sides. A hotshoe flash can't do this very well as the light heads forwards, so again the widest zoom setting is going to be the best here. I actually use my softbox with a Gary Fong Lightsphere attached to my Flash head, inside the softbox, in order to simulate a bare bulb type of light.

With a big umbrella, and for softboxes, a case could be made that we should in fact use our Flashes Wide Angle Panel in order to further widen the light spread.

Generally modifying the spread of light or angle from the umbrella or softbox is probably best done by moving it around, or partially closing the umbrella if wanting to restrict the light. When the modifier is turned slightly away from the subject to create a fall-off, this is known as 'feathering' the light, and is a softer way to change the angle that the light is hitting the subject from rather than flash zooming.
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pschlute

Link Posted 12/06/2017 - 06:32
Thanks for that Nigel.
Peter



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cardiffgareth

Link Posted 13/06/2017 - 20:42
As Nigel said but to add, it also depends on if your softbox as some are umbrella style with the flash facing forward (like a shoot through brolly) and some the flash faces backwards like a reflected brolly. As light exits the flash head it scatters so having it zoomed wide allows it to scatter more thus giving a more softer light. If the flash head faces backwards then zooming the flash won't give a hot spot of light as the light is being reflected from the back of the softbox but it will give it more power.

What Nigel says about feathering the light is a very good technique. You may want to look at forming a scrim also, as when used in front of a softbox at an angle can make excellent gradients of light. Simple to do, make a frame and put this here over it
Gareth
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pschlute

Link Posted 13/06/2017 - 21:48
Thanks Gareth. Lots of different techniques to try!
Peter



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