HSS ?

[Nemrod]

Right now this may not be relevant to many shooters but there are cameras on the market now and for a little while that support HSS strobes, for example, the Sony A6XXX series. And I know there are others. But, at this time, there is only one UW strobe that allows manual HSS and that is the Retra strobe. But surely there will be others in the fullness of time.

So, a strobe only has so much power, at full dump, that is maximum output. A HSS strobe flashes multiple times in quick succession therefore the light output W is spread over X number of flashes while the shutter blades are open rather than just one single flash. The power of each flash is W/X (W being total watts and X being the number of flashes) but the sum total of all the flashes is still the same as if it were a single flash?

How do we see HSS being used in UW photography? For one thing it allows any shutter speed which could be useful.

James

 

[Interceptor121]

The power of HSS is much less than a single shot. There are situations where this is useful on land typically when you want to shoot a wide aperture and avoid filling up the ambient light
Underwater I think macro will be more useful because sunburst are small apertures and need full power
So not much use for wide angle but could be good for bokeh and similar portrait work

 

[stuartv]

I basically agree with @Interceptor121.

HSS is only used when shutter speed is faster than 1/160 - 1/250 (depending on your setup).

I don't think I have ever used a shutter speed that fast (underwater). I'm not super experienced underwater, so that isn't saying much. But, it's hard for me to imagine anything underwater needing a SS that fast. Unless maybe you're trying to get lucky catching a Mantis Shrimp in mid-strike or something.

That said, I am all about having the tools - for "just in case". So, I am happy to have bought the UWT TTL trigger and planning to buy a pair of Retra Pros eventually... My rig won't be any larger or weigh any more for having TTL and HSS inside... And heck, my wallet will be a lot easier to carry around... LOL

 

[Interceptor121]

I have used 1/1000 or 1/2000

Sunburst by Interceptor121, on Flickr

 

[stuartv]

I have used 1/1000 or 1/2000
View attachment 575785Sunburst by Interceptor121, on Flickr

So, you were using HSS for that photo? Or a video light?

 

[Barmaglot]

My bet would be on an RX100 series compact.

 

[Nemrod]

I too have used fast shutter speeds with my S90 well beyond 1/250 to control background exposure. But my D-2000 strobes are one stop less than a Z240 and I figure 2 full stops below a Z330 (or Retra), thus my (possibly imagined) want to use a wider aperture to properly expose my close subject with my new A6400. I used the shutter speed to control the back light or sun ball and the aperture to set for the subject and chosen strobe output. Thus my question about HSS. I know it reduces the total strobe output but the only strobe we have now with HSS capability, the Retra, is not exactly a weakling. I can see using the HSS to allow higher shutter speeds to control the back light. I imagine a Retra Pro even in HSS would have enough power to expose the subject. I admit, I do not know, thus my asking.

I guess if I purchase new, more powerful strobes, then my question, for myself, is rendered mute. I would get my two stops back and would not need the HSS. Instead of 1/500 and f5.6 (S90, dual D-2000 with diffuser GN17, ISO100) I could use 1/125 (two stops below 1/500) and f11 (two stops above f5.6) for the A6400 as an equivalent exposure but I have to increase my strobe output two stops to get my close subject exposed equally at f11 at ISO100!

James