HSS. Why?

[wfooshee]

I would like someone to explain to me what good it is to have HSS.

I understand what it is, I understand being able to use flash with shutter speed faster than your normal sync speed. I've played with it on my D7000 and SB-600 just to see it work, both on-camera and off-. I shot my living room in the dark at 1/8000, and it works, although it was underexposed.

So what I don't understand is what good the flash does when the power is so much reduced as it is to make HSS possible in the first place.

I've heard people say that they might need fill flash but the ambient light is too high to be able to use the normal sync speed on the shutter. But if your ambient is so much that your need fill-flash or auxiliary lighting at say, 1/500 or 1/1000 second shutter speed, then it seems to me that the reduced lighting power available in HSS would make it pretty much useless.

 

[Overread]

This video might help you :




In short highspeed sync gets around a limitation on the hardware of the camera and flash unit which would otherwise mean you couldn't use flash at all at shutter speeds faster than the sync speed (at least not without black bands appearing).

When the ambient light is too strong and you have to use a faster shutter speed (or the shot requires it for creative effects) then the flash is putting out much less light. However it is typically often enough to take the edge off shadows. This can mean; as an example; that you can get softer shadows even in midday sunlight; rather than dark, hard shadows.

Note also that the video above shows some additional creative uses of highspeed sync.

 

[pgriz]

You're shooting something in daylight at f/1.8 (for thin DOF) and 1/2000 sec. You need some fill. How else are you going to get it if you don't have something like HSS?

 

[Derrel]

FILL flash is often shot at Minus 2 to Minus 3 EV below the ambient light exposure. The loss of effective Guide Number of a typical GN 110 flash (for example, Nikon SB 800,SB 910, Canon 580 EX-II,etc,etc) is really NOT much of a factor in typical fill-flash work done at normal outdoor people photography distances. In even more plain language, fill flash requires only the very tiniest little bit of flash power. The loss of effective GN is not really a significant "problem" in actual use.

Consider a typical Sunny 16 Rule scenario. At ISO 200, the daylight exposure is f/16 at 1/200 second. LOTS of pepper specks on the pictures from even the slightest dust on the sensor...skies LITTERED with crisp, dark, BLACK specks on every single image!!!! Hooray!

With High Speed Synch, you could elevate the shutter to 1/6400 second and f/2.8 for an equivalent exposure. That means you've just increased the actual aperture value by FIVE full EV compared to the tiny hole that is f/16. Annnnnnd....since the fill-in light needs to be about 2.7 EV below the daylight exposure, you have seven and two-thirds EV "more power".

ANother way of looking at it: when shooting flash at f/stops like f/2.8 or f/4 or f/1.8, any of the wider stops, it takes very little flash power to expose a frame; it takes even LESS power to just fill-in the shadowy areas.

 

[18.percent.gary]

You're shooting something in daylight at f/1.8 (for thin DOF) and 1/2000 sec. You need some fill. How else are you going to get it if you don't have something like HSS?

A $22 three-stop ND filter.

 

[Village Idiot]

You're shooting something in daylight at f/1.8 (for thin DOF) and 1/2000 sec. You need some fill. How else are you going to get it if you don't have something like HSS?

A $22 three-stop ND filter.

And poop quality.

 

[Overread]

You're shooting something in daylight at f/1.8 (for thin DOF) and 1/2000 sec. You need some fill. How else are you going to get it if you don't have something like HSS?

A $22 three-stop ND filter.

Except that won't work

The ND filter blocks light entering the camera evenly over the whole frame. So sure your bright sections will have less light coming in, but in equal measure so too will the darker shadows. So you are still there with dark shadows that you can't lift.

The only way is to add light to those areas - a reflector or a flash for fill lighting are ideal and commonly used options. A flash has the bonus that its quick to use (just turn it on and off as you need it) plus you can do it solo - reflectors oft require someone or something to hold them.

 

[pgriz]

18.percent.gary: Just in case I didn't undertand your answer, can you explain how your solution will help with fill in the shadows if you're shooting in bright conditions, AND you're going for a thin DOF?

 

[runnah]

18.percent.gary: Just in case I didn't undertand your answer, can you explain how your solution will help with fill in the shadows if you're shooting in bright conditions, AND you're going for a thin DOF?

Magic...

 

[KmH]

Nah... Smoke and mirrors...

 

[18.percent.gary]

18.percent.gary: Just in case I didn't undertand your answer, can you explain how your solution will help with fill in the shadows if you're shooting in bright conditions, AND you're going for a thin DOF?

In your example of f1.8 and 1/2000 conditions, a three stop ND filter will reduce your shutter speed three stops to 1/250, your sync speed. So now you can use your regular flash at the appropriate power level (without HSS wizardry and associated limitations) and keep your skinny f1.8 DOF without busting the sync speed.

Since this thread is regarding flash photography I thought it would be obvious that I was talking about using a ND filter in conjunction with a flash for fill.

 

[Overread]

Most of the time highspeed sync is enough for fill on a typical sunny day. I think you're going for something more extreme if you need to keep the shutter speed within sync speed.

The only time I can think that you'd need fill light like that is if you're shooting something very fast moving (and thus you'd not want a series of flash bursts in highspeed sync because it would blur). However if you are shooting something fast moving and lowering your shutter speed chances are that means that your shot must be only flash dominated otherwise you'll get blur from areas exposed from the ambient light at 1/250sec.

 

[Village Idiot]

You're shooting something in daylight at f/1.8 (for thin DOF) and 1/2000 sec. You need some fill. How else are you going to get it if you don't have something like HSS?

A $22 three-stop ND filter.

Except that won't work

The ND filter blocks light entering the camera evenly over the whole frame. So sure your bright sections will have less light coming in, but in equal measure so too will the darker shadows. So you are still there with dark shadows that you can't lift.

The only way is to add light to those areas - a reflector or a flash for fill lighting are ideal and commonly used options. A flash has the bonus that its quick to use (just turn it on and off as you need it) plus you can do it solo - reflectors oft require someone or something to hold them.

I took it as he meant an ND filter with fill flash and no HSS.

 

[Rick50]

Informative thread. Lots of good stuff here.

 

[18.percent.gary]

I took it as he meant an ND filter with fill flash and no HSS.

Yep, that's what I meant to imply. I was just making the point that there are simpler and less expensive options than HSS flashes.

Heck, we did just fine with ND filters long before HSS technology recently came about.