In practical use is 1/4000 max shutter speed problematic for HSS

Have you found the need for 1/8000 sync speed very often when using strobe with hss?

Considering the Nikon D750 or D810 combining with the Cheetah Cl-600x for outdoor portrait use. Would I regret not having 1/8000?

Let us first consider some generally true characteristics of HSS flash...
Start with non-HSS guide number for coverage angle of flash for lens FL, then

1. divide GN by 2 (or more) for effective GN when in HSS (at 1/2EV shutter speed higher than X-synch speed), then
   
2. divide GN by 2 for each additional -2EV faster shutter speed chosen...
   
3. then divide final GN by f/stop for max effective range of HSS flash
   

silvermesa1 wrote in post #18298394
Have you found the need for 1/8000 sync speed very often when using strobe with hss?

Considering the Nikon D750 or D810 combining with the Cheetah Cl-600x for outdoor portrait use. Would I regret not having 1/8000?

If I'm understanding you, the question is about cameras, not your flash.

If that is the case, I think you are unlikely to be using 1/8000 with HSS so the difference between 8000 and 4000 will not have much of an impact.

As wilt is pointing out, the SS is crushing the effectiveness of the flash, but only you know your style and requirements.

I don't miss 1/8000 on my 6D, at all. But that's me.

Well, it is about how fast your aperture you wanna set and how bright or dark is the ambient light you wanna capture.
Typical bright mid day light is f16 (iso = shutter speed).
Just do the math if let's say you want to use f/1.4 or even f/1.2 (I got f/0.95 lens too ). What shutter speed do you need to expose the ambient light.

Off course we can also add ND filter to lower down your ambient light and slower down shutter speed.
Or we can wait till afternoon where the ambient light match your target shutter speed

After you know what ss you wanna set then measure if the hss flash (with modifiers if any) can deal with that ss setting.

You can always use ISO50 if needed.

I have posted this before, f1.8, 1/4000. XPLOR600 at almost full power, medium softbox.

Before HSS, I used to use ND filter but lot of times, nothing at all. Here using no ND filter to let the bg blow out. 1/4000 would have been more than enough here.

f2.2, 1/250, ISO 50

silvermesa1 wrote in post #18298394
Have you found the need for 1/8000 sync speed very often when using strobe with hss?

Considering the Nikon D750 or D810 combining with the Cheetah Cl-600x for outdoor portrait use. Would I regret not having 1/8000?

I don't think so. One stop... I use Elinchrom (HS) and end up at 1/5000 often. It really depends on lighting conditions and your desired results.

silvermesa1 wrote in post #18298394
Have you found the need for 1/8000 sync speed very often when using strobe with hss?

Considering the Nikon D750 or D810 combining with the Cheetah Cl-600x for outdoor portrait use. Would I regret not having 1/8000?

Since HSS turns the flash into a constant light source the difference between 1/4000 and 1/8000 shutter speed is determined by the ambient light. The other two ways to get the 1 EV is with ISO, down to 50 from 100, which with some cameras is an imperfect option. Or, stopping down the lens which may significantly change the visual character of the image.

With HSS, going from 1/4000 to 1/8000 means increasing the light output 1 EV which means moving the light closer or increasing the power.

As others have said, if you can get the shot you want today with 1/4000 as a maximum shutter speed, adding HSS light to the mix won't change the requirement.

Heya,

I rarely need even 1/4000s with my strobe doing HSS. And guide numbers are largely useless for HSS.

But I got over the F1.4 and F2 thing, and found I like the look of my subject fully in the depth of field, ears and noses and all in focus, not just eyes and a profile.

I shoot at F2.8 these days for my "wide open" and I like it better overall. I am pretty much always under 1/4000s in the light I tend to use outdoors with direct in-FOV sunlight (generally late afternoon light).

I shoot family / spontaneous, not models, so I cannot recreate a lot of the moments we capture:

1/3200s, F2.8 in evening sun with HSS

IMAGE LINK: https://flic.kr/p/MKMw​xu

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IMAGE LINK: https://flic.kr/p/RiLm​np