Speed lights in strip boxes. Anyone done the test?

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Cistron

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Mike
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Greetings everybody,

I know I can be a nuisance, but that's how scientists are at times. We always want to see experiments and draw our own conclusions.

@Garry Edwards is adamant that a standard speed light with integrated reflector couldn't possibly fill a strip-box. I've been scouring the web wide and long, but haven't found anyone doing the tests. (Maybe I used the wrong terms)

My hunch tells me that without modifications and without a diffuser cap, Garry is right. However, with a little bit of aluminium foil glued to the inside of the Stofen-like diffuser, surely it must be possible to direct more light sideways.

Anyone tried or found some tests? Anyone keen to try?

Mike
 
I have done the test, and I am right..
However, it's a fair question so (hopefully) tomorrow I'll re-do the test and post the results, with my SB-800 as is. But I don't think I have a Stofen-type diffuser, so perhaps someone else can help with that.
 
No inner diffusion, but there is an optional reflector plate.

IMO, design/construction will matter a lot regardless of the type of head/flash used. The shape of a stripbox just wants to create a hotspot... not that it's necessarily a bad thing.
 
•

Since the power will be heavily diffused,
maybe the option of two flashes shooting
at the opposite long sides could bring some
solution.
 
I am assuming some form strobe is best then? Would bare bulb type flash work?
 
Kodiak Qc said:
•

Since the power will be heavily diffused,
maybe the option of two flashes shooting
at the opposite long sides could bring some
solution.
Click to expand...
Sure this would work, however it would require a more complex bracket.

si019 said:
Would bare bulb type flash work?
Click to expand...
Of course, but they are several times more expensive then simple speed lights.
 
•


To establish some parameters:

— a soft box will always "cost" a lot of light because of the required diffusion
— a speed light emits only toward the front
— a way to improve the light diffusion is to use a "ball" type of diffusor on the gun
or simply slide out the integrated diffusor
— bare bulb flash is the best but be careful with the heat generating modelling lamp
— two diffused guns shooting each to its long side in the strip box will resolve some
power and diffusion issues - more so with the inner baffle
 
Cistron said:
Sure this would work, however it would require a more complex bracket.
Click to expand...
•

Yes, but cool solutions are readily available on the market
and there is always my favourite way: the DIY solution.
 
Here's a very quick test done with a Nikon SB900 and a standard studio head, it's the same 90x30 Softbox in both shots, the SB900 had its stofen fitted and was in the widest zoom position.

If I get the time I might try with some different softboxes (which probably means I won't).

bbvfs1.jpgbbvfs2.jpg
 
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Right, I've now tested my SB-800 in both our 27 x 140cm Profold strip softbox, and our earlier model of non-folding softbox, both of which which I would describe as a full length strip softbox, i.e. it's long enough to light the whole of a standing person.
I only measured the centre of the front diffuser and about 5cm in from each end.

The flashgun was set to its shortest zoom length, 24mm, to maximise the light spread.

The flash meter readings were as follows with the PROFOLD:
Centre - f/2.8 d4
Top/bottom edge - f/1.4 d2

So, 4x as bright in the centre

And then I re-tested with the NON-FOLDING version, and the flash meter readings were as follows:
Centre - f/4
Top/bottom edge - f/1.4 d2.
So, nearly 6x as bright in the centre.

The reason for the difference between the two softboxes is that the Profold has a mechanism that acts as a deflector, pushing the light in the centre backwards, where it then bounces around off of the walls. This helps to even out the light distribution even with studio flash/barebulb flash, and obviously is a big help with a hotshoe flashgun.
softbox_deflector.jpg

Edit. Image doesn't seem to be showing, here is the link instead https://www.lencarta.com/image/data/softboxes/softbox_deflector.jpg
 
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Garry Edwards said:
Right, I've now tested my SB-800 in both our 27 x 140cm Profold strip softbox, and our earlier model of non-folding softbox, both of which which I would describe as a full length strip softbox, i.e. it's long enough to light the whole of a standing person.
I only measured the centre of the front diffuser and about 5cm in from each end.

The flashgun was set to its shortest zoom length, 24mm, to maximise the light spread.

The flash meter readings were as follows with the PROFOLD:
Centre - f/2.8 d4
Top/bottom edge - f/1.4 d2

So, 4x as bright in the centre

And then I re-tested with the NON-FOLDING version, and the flash meter readings were as follows:
Centre - f/4
Top/bottom edge - f/1.4 d2.
So, nearly 6x as bright in the centre.
Click to expand...
How does the fall off compare with a studio head?
 
Sharky said:
How does the fall off compare with a studio head?
Click to expand...
In the Profold version, the fall off with a studio head is just over 1/2 a stop with this particular softbox. I haven't tested it with the non-folding version, but it will inevitably be more.
 
Garry Edwards said:
Can I ask what the light meter readings are on your tests?
Click to expand...

I didn't use one, I just wanted to provide a quick visual example as it's one of those things which gets brought up a lot.

I had a few other strip softbox brands a while back, kinda regretting they're not on hand as we could see if there's much difference between brands.
 
Cistron said:
Ouch! What make was it?

Btw. would you mind testing the Stofen with a little aluminium foil around the front and short sides to force the light towards the arms of the strip-box?
Click to expand...

It was an old Profoto speedring, they use a different design now and hopefully better material.

When I get a chance sure, I expect it'll make the results more consistent but that must really eat into the total output.
 
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