I'm the first to admit; I don't understand my Sb 800 or that menu to save my life. Perhaps one day...sigh

If you only needed full power of 1 light, 2 at half power should give you the same, and therefore decrease recycle time. It's just like non-hss, the more, the merrier.

Yes! Grouping flashes means less power use and faster recycling times!  I know a photographer who has literally like 9 flashes that he groups in 3's and he says how it saves on power and recycling without fail!

I can only speak to Nikons so as long as they are grouped (as in flash groups) - i.e. for Nikons they are either "A, B, or C" if memory serves (don't have it in front of me); the default "channel" is "1" (if memory serves). Yes, if the flash is HSS capable with an HSS capable camera and commander flash, it is no different than using CLS with Nikon gear.

As far as the physical grouping of two or more flashes together, it does decrease recycle time and power use just because they have to put out less light to properly expose the subject. I.e. you will be able to place more light on the subject with less effort (hence, less power).

The more the merrier is exactly, right, sir!

Brian, it is a lifesaver, bro! You do not have to do anything to the SB800 to use HSS!  All you have to do is have an HSS capable camera and when you set the camera to HSS, the SB800 sees it and automatically sets itself! And once you set it on your camera, just leave it there and the SB800 will automatically go to "Auto FP" HSS flash mode once you place it on your hotshoe or set it up using CLS! Easy!

I'll call you to ask about how to set it up . I get frustrated with the metering of it...

Of course! The more light the better!

And it is all in fun! Just trying to get some useful info out there and gain some folks some exposure....

Since you're shooting at a higher shutterspeed (1/3200 in your example), the shutterspeed itself will stop motion (like sports) rather than the flash duration.

Yup, I've used 6 together on a shoot before now firing through a 4ft diffuser to make sure I had quick enough recycle times without overheating the flashes.

This test shot was 1/500th @ f/5.6, but the actual images were 1/2000th @ f/2.8.

Whatever mode you want.  I go full manual, and set my flashes to manual power too.  You could do it in P mode with full on TTL too if you wanted to.  Choice is yours.

To a point.  The flash still has a crazy fast duration.  Because it's working in much lower power bursts, a 1/2000th of a second shot, for example, could end up being an 8 flash burst of the flash to cover the entire sensor, and each of those 8 flashes might only be 1/50,000th of a second in duration.

Actually, and I hadn't really thought about this before, but it does bring up a potential issue.  If you're shooting a super fast object, different parts of the sensor are being exposed to your flash lit subject at different points in time (freezing a chunk of the shot at a time), so the photo might transition noticeably forward or backward in time as you go from the top of the photo to the bottom - as opposed to just shooting in a black room and having a pop of flash to freeze everything at once.

Will have to experiment with that.

I think you misquoted me - in actually, I believe I said in the article that you LOSE the ability for real stop action because the flash duration is actually longer. That is one of the drawbacks, actually - you may get some ghosting with moving subjects from my experience...

Admittedly, I have not experimented/used the vari-ND.  I will have to give that a try soon and compare performance!  Thanks for chiming in, sir!

I do not know - I am sure some are most likely!  You just have to check the individual specs! I am a Nikon shooter and only use Nikon speedlites...

I am not sure about this - I have had some issues stopping action when using HSS.  At least at certain shutter speeds - maybe this is a bit quirky where the camera is better able to stop action at certain speeds?  Maybe it is some performance issue with my camera - I dunno...<shrug>

I usually shoot in aperture priority to control DOF - I also shoot in Manual, as well...

The flash duration isn't actually longer (technically - it's a combination of several flash exposures), it's several even smaller flash durations, because the flash isn't acting at full power.

But, as you said, ghosting with moving subjects (although each flash burst is extremely fast in duration).

It is just that simple - IF your camera and flash are HSS capable!

Oh - got you!  My bad - but yes, I think this can be an issue with moving subjects.  As with anything else, perhaps how fast they move is the main problem...

Thanks for chiming in!

No problem.  Experimenting with HSS is great fun.

One of the the first shots I took with HSS was of a street juggler. The clubs were multiplied in a kind of strobing effect. I quite liked the effect but it was not what I expected.

I had the opportunity to play with this today on the beach. It was pretty amazing.  You don't see any ghosting at f-1.4 - 8000th of a second

I get what you mean about how you'd figure the ghosting would be there, but hypothetically speaking, if the flash duration is 1/500th at full power, the shutter is going to do 1/8000th regardless so the flash duration is moot since it's on the entire time the shutter is open.

The problem is usually when your flash duration is faster than your shutter speed.

I could be wrong, but that's how I picture it happening. (no pun intended, or maybe it is)

In theory, sure, in reality, it's not that slow.

If you're shooting 1/8000th of a second, you're not just getting one big long duration flash pop.  You're getting a series of much smaller flash pops (which is why you lose light - if it has to do a dozen or more flash pops to cover the entire scene a slit at a time, it can't possibly do each of those at full power that rapidly).

Each of those flash pops might be as fast as 1/20,000th of a second or even shorter at much lower power settings.

Indeed, and it is.

So, I'd say that depends on whether 1/8000 shutter speed without flash would actually be fast enough to freeze your subject or not (light level issues and high ISO performance aside).

If your subject wouldn't be frozen even at 1/8000th, that's when you may start to see ghosting from the flash pops (which would probably be closer to 1/20,000th of a second each or less).

sorry not picking on you specifically but this whole discussion is leaving me scratching my (shaved) head. All this talk about ghosting on location shoots at 1/8000 sec??????  since when do models move fast enough to not be frozen at 1/8000?  for that matter since when do they move too fast (even in a jump-in-front-of-the-sun) or 'throw their hair out of the water" or 'jump into the water" to not freeze them and the water droplets (as applicable) around them? I don't even have a camera that shoots at 1/8000 and I've never had a model move fast enough. 

Anything moving fast enough to not be frozen at 1/8000 needs to be booked for the next filming of "Time Warp" on Discovery channel.  or perhaps "can you outrun an explosion?" on Mythbusters" (what size boobs are optimal for outrunning an explosion?) (when you jump while outrunning the explosion do you move faster? or is it just a gratuitous exhibition of your cleaving bouncing?) etc etc.

Also, at that speed, even with ISO 100, the DOF is going to be so narrow that you are more worried about parts of the model moving out of focus unless they are 100% constrained to move only in the plane of the shutter.

Sure, not models, but I've shot peregrines flying at full pelt not get frozen at 1/8000th.

There are plenty of things that happen faster than 1/8000th of a second though, that's why there's a whole load of people doing high speed photography (which is not high speed sync).

High speed photography is flash durations of 1/10,000th or less.

https://www.google.co.uk/search?q=high+ … 0QX-i8zoAQ

HSS and HSP are things you probably won't need to use regularly, but you'll be glad you know how to do it in the event you need it.

Just another tool in the arsenal.

http://webs.lanset.com/rcochran/flash/hss.html

Thanks Caradoc.  I vaguely remember seeing that a couple of years ago.