Biggest Softbox for a speedlight with a9iii

[subferno]

I will be receiving the Sony a9iii with the F60rm2 speedlight soon. Whats the biggest softbox I can use with this speedlight, outdoor and overpowering the sun. This is for portraiture, distance of the speedlight is probably 7 feet away. Also take into consideration that the a9iii is a global shutter.

Thank you

 

[NAwlins Contrarian]

I will be receiving the Sony a9iii with the F60rm2 speedlight soon. Whats the biggest softbox I can use with this speedlight, outdoor and overpowering the sun. This is for portraiture, distance of the speedlight is probably 7 feet away. Also take into consideration that the a9iii is a global shutter.

Are you looking for a mini-softbox of the type that normally mounts to the flash itself, when the flash is mounted in the camera's shoe? I'm seeing for example Vello models in "Mini", 8" octo, and 12" octo. But if used on camera, presumably at some point you run out of clearance between the bottom of the softbox and the top of the lens or field of view. Or do you want some sort of bracket to join the flash (off camera) to a regular softbox?

FWIW, shoe-mount-type flashes with Fresnel lenses are not great at filling softboxes and similar. To mitigate the problem, you could (probably should) manually set the flash to one of the wider zoom settings.

 

[Gato Amarillo]

I will be receiving the Sony a9iii with the F60rm2 speedlight soon. Whats the biggest softbox I can use with this speedlight, outdoor and overpowering the sun. This is for portraiture, distance of the speedlight is probably 7 feet away. Also take into consideration that the a9iii is a global shutter.

Thank you

I'm not sure that speedlight can overpower the sun, even without a modifier.

At any rate, there's probably not much point in a softbox bigger than about 20 or 24 inches with a fresnel speedlight. The light just will not spread enough to fill it.

Gato

 

[Ralf B]

I will be receiving the Sony a9iii with the F60rm2 speedlight soon. Whats the biggest softbox I can use with this speedlight, outdoor and overpowering the sun.

I'm not sure that speedlight can overpower the sun, even without a modifier.

The a9III takes care of that in combo with the flash thanks to its GSS
The video linked above is only one of many on the same capability of the a9III
Cheers,
Ralf

 

[Ellis Vener]

I will be receiving the Sony a9iii with the F60rm2 speedlight soon. Whats the biggest softbox I can use with this speedlight, outdoor and overpowering the sun. This is for portraiture, distance of the speedlight is probably 7 feet away. Also take into consideration that the a9iii is a global shutter.

Thank you

Q1: Will you keep the flash on the camera, or will you also use it as an off-camera flash?

If you plan to keep the flash in the camera's hotshoe and have the speedlight point straight ahead, the size of the softbox will be limited by the distance between the center of the flash and the outside of the lens hood, or, if you don't use a lens hood, by the barrel of your largest lens. That distance is half the width of the short side of a rectangular softbox or the radius of a round-faced or octagonal softbox.

Alternatively, you can use a softbox like the Rogue FlashBender v3 Large Soft Box Kit, https://www.rogueflash.com/products/flashbender-v3-large-soft-box-kit, or the Rogue FlashBender v3 XL Pro Lighting System https://www.rogueflash.com/products/flashbender-v3-xl-pro-lighting-system, where the flash points up into a softbox.
These have the advantage for portraiture or moving the radiating surface of the softbox away from the lens axis, which, for most faces, creates more flattering lighting.

The upsides of using a hotshoe-mounted flash:

- It's convenient. no extra gear like lightstands to cart around

- You like the look of an on-camera light.

- If there are nearby white or light-colored walls or a ceiling, you can change the quality of light by pointing the flash at the wall or ceiling. That larger surface becomes a large reflector. But if you do that, my advice is to remove the softbox.

- By setting the flash to underexpose, it can be a nice fill light or a catchlight in the eye

The downsides:

- You might not be happy with the light always coming from near the lens. That's important since you say you'll be doing portraiture.

- If you use the camera in portrait orientation, the light is no longer coming from above, but from either the left or right.

- You might want to try using a larger softbox or an umbrella to create more flattering light. That's important since you say you'll be doing portraiture.

Q2: How easy do you want the setup and removal of the softbox to be?

All light modifiers mean more complexity. While I like the Rogue FlashBender products, they take two or three minutes to set up and secure to the speedlight. They also increase the overall size of the camera, flash, and softbox setup.

Q3: Why seven feet?

Unless I am going for a specific look, such as a head-and-shoulders portrait, I prefer to maintain a normal, conversational distance between the person and the photographer. Obviously, if I want to see more of the person's body in the photo, I work at a greater distance. Even when that's the case, if I am using OCF lighting, I can have the light and softbox closer to the person than the camera has to be.

Q4: about overpowering the sun

Are you trying to make the areas lit by the sun underexposed relative to the flash-lit areas? If that's the case, Speedlight + Softbox + seven-foot distance is going to be tough, even with a global shutter. As you shorten the shutter speed, you'll have less light to work with from the flash.
Or do you really mean lighting the person so they stand out against a normally or even slightly underexposed sunlit background?

--
Ellis Vener
To see my work, please visit http://www.ellisvener.com
I am on Instagram @EllisVenerStudio

 

[NAwlins Contrarian]

I will be receiving the Sony a9iii with the F60rm2 speedlight soon. Whats the biggest softbox I can use with this speedlight, outdoor and overpowering the sun. This is for portraiture, distance of the speedlight is probably 7 feet away. Also take into consideration that the a9iii is a global shutter.

I'm not sure that speedlight can overpower the sun, even without a modifier.

The A9 Mk. III could really be a gamechanger in that regard if you used a flash with a short enough t 0.5. I don't know the practical answer, but presumably people have tested it. Maybe somebody will link us to some well-done tests.

A full 'Sunny 16' exposure in a camera with an X-sync speed of 1/250 s would be e.g. ISO 100, 1/250 s, f/10. So if part of the field of view was illuminated by full sun and you were trying to balance a shadowed part, and your flash had an effective outdoor Guide Number of 25m = 82 ft, then your flash would have to be around 2.5m = 8.2 ft from the subject, but at that point it should work. Obviously if you can get it closer, then you can provide brighter-than-full-sun illumination.

But if you want to shoot at e.g. f/2.8, then to properly expose the sunlit areas, your shutter speed needs to be 1/3200 s. So that means you're in high-speed sync territory (assuming your flash supports it), and the illumination lost to the pulsing HSS may be greater than that gained by the larger aperture, so you've got to move the flash closer to balance the exposures. Sometimes you run out of flash output, especially if there are modifiers like the softbox the OP mentioned,

But the A9 Mk. III doesn't need HSS. It can sync at 1/3200 s, at least with a Sony HVL-F60RM2 and some other flashes. It would seem then e.g. that if the F60RM2's t 0.5 is 1/5000 s, this might work fine, but if it's 1/500 s, not really.

This is all my theoretical musing. Maybe somebody sees something I'm missing. Or maybe there are tests. Inquiring minds want to know.

 

[Ellis Vener]

This video is very good, lots of very useful information and his conclusions are solid.

 

[NAwlins Contrarian]

This video is very good, lots of very useful information and his conclusions are solid.

Thanks, that was an interesting watch covering some of the issues that a global shutter with a very high shutter speed presents for flash exposure. It explains and gives one demonstration of the issue I raised.

From the examples starting at about 6:12, we can see that with the fastest 1/80,000 s shutter speed, flash illumination of the subject is about the same at full power as at 1/16th power, and thereby infer that at maximum shutter speed, that flash (Godox AD200 Pro II) can provide at most four stops less illumination than its maximum with traditional sync speeds (about 1/300 s and slower). And it could be less than that; e.g. would the 1/64th power setting have provided about the same subject illumination, and therefore the effective output is six or more stops less that the 'slow sync' output?

But I'm left to wonder where's the effective start of limiting shutter speeds for various popular flashes. Obviously the demonstrated 1/80,000 s is the worst-case scenario. In my example above, I'd forgotten that the 'real' base on the A9 Mk. III is ISO 250, but at that setting, you could balance full sun at f/2.8 and a shutter speed slower by a factor of ten, i.e., 1/8,000 s. With 1/8000 s, would an F60RM2 or AD200 or whatever be able to deliver within a fraction of a stop of its full (e.g., 1/250 s) output? Or seen another way, if the flash can provide essentially full illumination at a shutter speed slower by a factor of a hundred, i.e. 1/800 s, then the A9 Mk. III would provide some advantage over a traditional-type camera with a base of ISO 100 and a maximum X-sync speed of 1/250 s. At 1/1250 s the advantage would be a full stop.

Interesting times.