High Speed Sync

@JBPhotog we all have our preferences, mine is more toward the uneven balance with more Iris to show the color. I'm old school on modeling lamps, and with the them set to tracking I haven't had a problem with constricted pupils.
 
@smoke665 I'm confused, you said constant light constricts the pupils to pinpoints. Isn't a modelling lamp a constant light? The strobe firing is too quick for the pupil to react so it is the modelling lamp that determines the pupil size and in turn the amount of iris shown.

With a number of cameras having dual ISO sensors, one can use a higher ISO with minimal ambient light to capture the image at a reasonable fast shutter speed. My personal choice is strobe with modelling lamps bright enough to have a healthy amount of iris.
 
I'm confused, you said constant light constricts the pupils to pinpoints. Isn't a modelling lamp a constant light?
I've used Paul Buff in studio for years, with a wireless Cyber Commander controller that allows me to adjust individual lights. Each light has the option to synch the modeling light to the flash power setting. In other words, as you increase the power the modeling light increases conversely as you decrease the power the modeling light intensity decreases. Typically that sync intensity on the modeling light gives me pupils of about the right ratio of pupil to iris.
 
Interesting conversation.

I have to disagree that LED panels are a practical light source "In Many Situations" .

Do you think my cat would have waited for me to get another tripod out and setup the LED panel ???

It is just not practical for me to use LED panels in 95% of the photography I do. If I am walking around a nature reserve or a quick trip up to a local park why would I want to lug another tripod + LED panel ??

I use my flashes a lot on pretty much everything I photograph. GODOX V1 + 2 x MF-12 + X-PRO Wireless trigger gives me a huge range of options that cannot be achieved with LED panel:
- Off camera flash for those difficult to reach places
- Pin point placement of extra light
- Combined the three flashes synced can produce a black background on a sunny beach at midday (Inverse Square Law)
- Background or hair lighting with the small flashes gives depth to an image that is just not possible with a single LED panel and is difficult to achieve with several.

I could go on and on and on. The bottom line is that I own 3 flash units + multiple diffusers and zero LED panels.

At some point my attention will turn to video and I will look at continuous lighting.

CHEERS
JBO
Another option to HSS is to keep your shutter speed at the maximum sync before it goes into HSS, say 1/250 and use the minimum amount of power from your flash to freeze the action. Effectively, it is the flash burst that acts as the shutter providing 1/250 at your ISO and f-stop doesn't let in any ambient light. FWIW, my AD200 at 1/128 power fires at 1/13,333 of a second. The caveat with HSS is, the higher your shutter speed goes the lower the output of your flash as it negotiates the number of flash pulses to cover the sensor at that given shutter speed. This is one of the reasons outdoor portrait shooters use ND filters on their lens when shooting lower f-stops and flash so they don't have to go into HSS.
 
Another option to HSS is to keep your shutter speed at the maximum sync before it goes into HSS, say 1/250 and use the minimum amount of power from your flash to freeze the action

Actually when shooting action or moving subjects, this is the preferred method over HSS, because even though the flash is firing at lower power (shorter duration) on HSS, the pulses are delivered over a period equal to the maximum sync speed of the camera, effectively canceling out the action stopping ability of the shorter flash duration.

This is one of the reasons outdoor portrait shooters use ND filters on their lens when shooting lower f-stops and flash so they don't have to go into HSS.

Yes you can, but the problem with ND filters is that they're global, affecting everything equally (Unless you're speaking of a graduated). HSS is more targeted, it allows you to open your aperture to blur the background AND still darken the background/sky while properly exposing the subject, shooting at base ISO. NDs especially graduated, can still be used with HSS. IMO, the added advantage of HSS is, it adds a certain amount of "pop" to the image not found in a single flash discharge, as in this one - f/2.8, 1/1000, ISO 100

Lizard20240407_0209.jpg by William Raber, on Flickr

The caveat to HSS is as you mentioned early, "reduced flash power" because of the multiple pulses. Because of that, HSS requires you to be close to the subject, and not suitable for situations where the subject is far away.

HSS has it's place in a photographer's toolbox, knowing when and how to use it effectively is the key, same as any other tool at our disposal
 
Not sure what you mean by "pop" specific to HSS since preferred exposure can be achieved in either way, ND or HSS. When I mention ND I am not referring to a grad ND, my preferred method is a variable ND, 1-9 stops.
 
Not sure what you mean by "pop" specific to HSS since preferred exposure can be achieved in either way, ND or HSS
Again ND filters are global - highlights, midtones, shadows are all affected equally. In the example I posted above, it was shot mid day sun. An ND will not allow the same degree of separation that HSS did, making the subject more prominent (pop) against the background.

I've used both NDs and HSS as stated earlier I find each has their place. Use what fits your needs
 
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Again ND filters are global - highlights, midtones, shadows are all affected equally. In the example I posted above, it was shot mid day sun. An ND will not allow the same degree of separation that HSS did, making the subject more prominent (pop) against the background.

I've used both NDs and HSS as stated earlier I find each has their place. Use what fits your needs
I think you missing an important component when using an ND, you get to open the aperture the same number of stops of the ND essentially achieving the same results as HSS.

For example, the sunny f16 rule, ISO 100 at 1/100 sec at f16 for proper exposure. But you want the subject to be isolated from the background so you'd rather shoot at f2.

HSS: You are opening the aperture 6 stops and changing your shutter speed from 1/100 to 1/6400, again 6 stops. The exposure is the same in both cases but you want a bit of flash on the subject so you are now in HSS.

ND: The same can be done by adding a 6 stop ND, keep the aperture at f2 and lower. the shutter to 1/100. Now you get the same shallow DoF and your flash is well within your cameras sync without going into HSS.

If you want some background on this see this YT video:
 
I think you missing an important component when using an ND, you get to open the aperture the same number of stops of the ND essentially achieving the same results as HSS.

No, you're assuming it has to be an either/or choice. Read my post above "I've used both NDs and HSS as stated earlier I find each has their place,. use what fits your needs". Both ND filters and HSS allow you to shoot at wider apertures to darken/blur the background, but there's no free lunch they each have their pros and cons.

The biggest pro on an ND is you can use whatever flash power you need up to full power. Its easier to meter the flash without the filter, then adjust the aperture to compensate. Unfortunately an ND affects the luminosity of everything in the scene, you may not have sufficient power to override the sun to darken a bright sky as much as needed, many times with an ND and flash you'll still get hot spots in the background peeking through, it's next to impossible to get a completely black background, (as in this one, f/4.5, 1/500, ISO 100).
Wildflower_0002.jpg by William Raber, on Flickr
and your ability to focus especially with AF might be a problem. Also, a cheap ND can affect image quality both color and sharpness, while a higher end ND can hit $300. Not a problem if you're shooting this type of shot regularly, but a little much for the occasional use.

HSS
Requires no extra gear, to get the same result. There's no degradation of the image color or sharpness from a low end filter. Your ability to focus isn't hindered, and as mentioned earlier my personal opinion is it pops the subject, my style leans more toward the sharp side, especially in the eyes. The downside to HSS is the flash power is automatically reduced by the pulses. In bright sun you may have to move closer to the subject, and flash battery life could be compromised, by successive multiple pulses, though I would think it would be the same as firing the flash on full power with and ND.

HSS and ND filters are "tools" and like all tools they each have their pros an cons. We all have our prefrences, shooting style, etc.,but, understanding how/When/where to use HHS or an ND makes us better in the end.

In any case this thread was about using HSS, rather than take it off rails further debating other methods, it would probably be better to open another thread.
 
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Interesting conversation.

I have to disagree that LED panels are a practical light source "In Many Situations" .

Do you think my cat would have waited for me to get another tripod out and setup the LED panel ???

It is just not practical for me to use LED panels in 95% of the photography I do. If I am walking around a nature reserve or a quick trip up to a local park why would I want to lug another tripod + LED panel ??

I use my flashes a lot on pretty much everything I photograph. GODOX V1 + 2 x MF-12 + X-PRO Wireless trigger gives me a huge range of options that cannot be achieved with LED panel:
- Off camera flash for those difficult to reach places
- Pin point placement of extra light
- Combined the three flashes synced can produce a black background on a sunny beach at midday (Inverse Square Law)
- Background or hair lighting with the small flashes gives depth to an image that is just not possible with a single LED panel and is difficult to achieve with several.

I could go on and on and on. The bottom line is that I own 3 flash units + multiple diffusers and zero LED panels.

At some point my attention will turn to video and I will look at continuous lighting.

CHEERS
JBO
You are mentally picturing studio panels on stands. I was referring to the camera mounted panels, about the size of a large speedlight.
 
I never used it with film, but it works the same way, although not many film cameras support it (some Nikons and Minoltas, from what I'm reading.) The camera and flash both have to support it, and they communicate with each other to pulse the strobe. It is NOT continuous light, or even "effectively" continuous light. Flash power is limited because of the energy required for multiple strobes per exposure, and speedlights are not capable of continuous light. You have a serious misunderstanding of what is happening with high-speed sync if you think it's continuous light.

If you do have continuous lighting (like your LED panels,) then you can shoot at whatever speed you like, film or digital, but it's not high-speed sync. It's not even sync.
If speedlights cannot mimic continuous illumination (via extemely fast "strobing") then you cannot explain how HSS worked with film.
 
If speedlights cannot mimic continuous illumination (via extemely fast "strobing") then you cannot explain how HSS worked with film.
I did explain it, giving the exact same process it uses for digital cameras. There are simply very few film cameras that support HSS. All I said was that I never used it with film, because I never had a film camera or flash unit that supported it. That's not an inability to explain it, and your question of "how does it work with film if it's not continuous" is irrelevant.

Read my lips: IT WORKS EXACTLY THE SAME WAY!

Film or digital DOES NOT MATTER. HSS pulses the flash in sync with the shutter travel so that even though the entire sensor is never exposed while the shutter is travelling, every area of the sensor receives flash. Your insistence on calling it continuous light is simply ignorant, especially since the process has been explained in detail several times in this thread.

Maybe this will help... Follow this link and scroll down to section 3 "How high-speed sync works."
 
@Golem I think I might have figured out the confusion, its in the method and technology used in HSS. On all focal plane shutters (film or digital) there is an instant when the whole sensor (or flim) is exposed to the light source. At speeds above the sync speed there is a slit that travels across the sensor, as the back plane follows the front, such that the whole sensor/film gets exposed equally. In earlier film cameras with leaf or petal shutters there was no moving slit, so sync speed wasn't an issue. However, they had a max speed limitation of around 1/500.

With focal plane shutters I haven't tried it but I'm assuming that a continuous light would expose a sensor or film at speeds above sync, since it's basically an ambient light shot. However it is NOT HSS because there is no synchronization between the light and camera that involves multiple flashes going on.
 
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I did explain it, giving the exact same process it uses for digital cameras. There are simply very few film cameras that support HSS. All I said was that I never used it with film, because I never had a film camera or flash unit that supported it. That's not an inability to explain it, and your question of "how does it work with film if it's not continuous" is irrelevant.

Read my lips: IT WORKS EXACTLY THE SAME WAY!

Film or digital DOES NOT MATTER. HSS pulses the flash in sync with the shutter travel so that even though the entire sensor is never exposed while the shutter is travelling, every area of the sensor receives flash. Your insistence on calling it continuous light is simply ignorant, especially since the process has been explained in detail several times in this thread.

Maybe this will help... Follow this link and scroll down to section 3 "How high-speed sync works."
The link you provided confirms my point that HSS is continuous light.

Your contention that each micro burst of flash in HSS is synched to each segment that the continuously moving slit uncovers, reveals that you believe in a level of techno perfection that cannot be achieved in the real world.

You have misunderstood whatever material you have read that led you to believe in the impossible.

HSS depends on high frequency pulsing that is effectively contnuous. Your belief that each pulse is dedicated and synched to its own narrow strip of the image, and that all these strips are merged perfectly at their edges, is ludicrous.

Ive observed all the patient attempts to explain TO ME how shutter curtains move and how synch works and have kept silent about the reality of the following fact: Ive always known all of that, AND MORE, inside out and upside down, forwards and backwards. Fact is, my having a far deeper understanding of it than you do is WHY I could never believe in your description of HSS tech.

Did you ever use "FP" class flash bulbs ? HSS mimics those. Both FP bulbs and HSS provide continuouse light of long enough duration to allow the shutter slit to comlete its travel. Its just that simple.

The incredible level of precision that would be needed for your imagined version of HSS operation is grossly unachievable, but that never occurs to you due to your lack of solid understanding of shutters and flash.

Again, I did read your link. The significant word in that little lesson is "duration". Reread it.
 
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