High speed sync enough?

[NAwlins Contrarian]

What is your practical experience regarding whether monolights or even shoe-mount flashes with high-speed sync (HSS) suffice in place of leaf-shutter lenses (which can sync at any shutter speed) in situations where you need to balance relatively bright ambient light with flash lighting on the main subject at large or moderate apertures?

In a thread in another forum (https://www.dpreview.com/forums/post/67209463), a user asked why Fuji doesn't offer leaf-shutter lenses for its GFX system. I suspect (and suggested) that the reason is that often HSS suffices. After all, today there are 600, 1000, even 1200 Ws monolights that feature HSS, and common lighting setups often involve more than one such flash. I realize that HSS reduces light output, and that modifiers like softboxes and umbrellas reduce it further.

But would, say, a kit with two or three Godox AD600Pro monolights allow you to light adequately and to your taste, where you have to balance with outdoor daylight, using HSS instead of X-sync or a leaf-shutter lens?

 

[RL Photography]

You are confusing High Speed Sync with HyperSync, which Elinchrom refers to as Hi-Sync. They are different things.

Other than name and mechanism used to increase the flash pulse duration in what way are they different?

HSS vs HS | Elinchrom

www.elinchrom.com

You keep talking about extending the pulse duration. HyperSync involves a single pulse. High Speed Sync involves multiple short pulses. The different approaches impact power loss when used and potentially how even the illumination is across the frame.

 

[Colin Creevey]

At full power flashes convert all the energy stored in their capacitors to light. The difference with HSS is that the conversion is slowed so the flash lasts for about 1/100th of a second.

That is not my understanding of the basic facts, but maybe I'm not understanding what you're saying.

Your understanding of the facts is wrong. HSS flash pulses are about 10ms long which is long enough to cover the transit time of the slowest focal plane shutters and allow a bit of timing slop.

About all the energy in the flash capacitors is converted to light in normal and HSS modes with HSS having some extra switching losses from the high frequency pulsing and probably leaving a bit more residual in the capacitor to avoid the light output tailing off towards the end too much. That's 1/3rd maybe 1/2 stop worth. People who talk about HSS losing 2 or 2.5 or 3 stops don't have a clue. HSS is down because it is used at shutter speeds where the sensor doesn't see all the produced light. How much down depends on the shutter speed used.

I did a test with images on another thread using an AD600Pro. My results mirrored those found on a Youtube video talking about power loss of using HSS on various products. That is, the AD600Pro lost 1.5 stops from going from non-HSS to HSS. And before you ask, yes this is not including the drop due to shutter speed.

If we take a shot without HSS at ISO 100, f4, 1/100 then according to you we should only see an exposure lost of 1/3 or 1/2 stops if we take another frame with HSS enabled. ISO 100, f2, 1/400. We have countered the 2 stops of light lost from SS by opening the aperture up 2 stops. However, as I showed in my test with images, it is closer to 1.5 stops given the parameters I was testing.

Where else do you think the stored energy goes in HSS mode?

Sunny 16 tells you at 100/th and F16 your sensor will receive X photons. Your flash guide number and F16 tells you what subject to flash distance you need to receive the same X photons from the flash. HSS produces the same number of photons (less 1/3rd or maybe 1/2 stop) over a 1/100th second which conveniently matches the sunny 16 1/100th.

The light intensity of an HSS pulse at guide number/F18 distance matches the intensity of sunny 16 sunlight. You were asking about balance and I thought this answers your question pretty well.

 

[Colin Creevey]

Source: https://fstoppers.com/lighting/demystifying-high-speed-sync-68527

Let me be clear: I'm not asking about how HSS works. I know how HSS works. I'm asking people who use HSS with monolights and/or shoe-mount flashes how often, if ever, they run into the problem of not having enough light output when in HSS mode, where they would have enough power if they could X-sync.

This is how I understood your original question and it is hard to answer generically as the subject matter and way of shooting is going to be different for multiple people.

I knew one local tog that had issues with output from a Godox AD1200Pro at full power under sync speed. However for me, I doubt I would never shoot what he was shooting and therefor wouldn't have that issue.

Were you just asking for interest or for personal advice?

 

[Colin Creevey]

Where else do you think the stored energy goes in HSS mode?

It hits the shutter curtain.

........after it has been converted to light.

I think what RL Photography is saying is that in a non HSS frame, all the light from the strobe flash hits the subject and is recorded by the sensor.

With HSS, we are pulsing. So say that it is pulsed three times, each with the shutter exposing 1/3 of the sensor. Then in this case, 2/3 of the light from each pulse is hitting the curtain and not reaching the sensor.

 

[Teila Day]

What is your practical experience regarding whether monolights or even shoe-mount flashes with high-speed sync (HSS) suffice in place of leaf-shutter lenses (which can sync at any shutter speed) in situations where you need to balance relatively bright ambient light with flash lighting on the main subject at large or moderate apertures?

Apertures f/2.8 and larger, 1/500th shutter, and the light(s) a 10ft. away from the subject at 100 iso? HSS can effortlessly offer a nice blend of "pop" to the subject when the sun is in front of ... all the way to 90 degrees to the side of the subject. Start closing the aperture (smaller), add modifiers, filters, the sun more behind the subject in the middle of a bright day, and push the shutter speed up to 1/1600 or more and power becomes an issue fairly rapidly, especially when you start moving the lights further away from the subject. Shooting a group of twelve (12) on the beach - you may have your lights 20ft. or so away from the subjects, circular polarizer on the lens, softbox with double white fabric baffles inside, etc.. you can start running out of power pretty fast... ** Put a grid on the flash(es) being used and the HSS performance gets worse 2-3 times quicker as one might expect.

My personal experience..

Aperture: f/14 (+- a stop)

Distance to subject: 10 - 25 ft. from the flash would be typical

Will HSS (high speed sync)/HS (hyper sync = different tech) "suffice"? ... in certain situations where I don't really need a lot of light to begin with, but when I need to set the power on a flash directly in front of the subject to 600ws or more (for example), and I'm stopped down around f/14 (medium format) then it can be a bit of a struggle using HSS (around a stop of light loss over leaf shutter all else being equal). At that power setting Nikon/Canon speed lights and even my old school potato masher Metz 76 MZ - 5, can't compete with studio strobes.

In a thread in another forum (https://www.dpreview.com/forums/post/67209463), a user asked why Fuji doesn't offer leaf-shutter lenses for its GFX system. I suspect (and suggested) that the reason is that often HSS suffices.

Cost. One reason you don't see a lot of people using (or the typical manufacture offering) leaf shutter lenses - because they require the associated camera, which today basically means using Hasselblad or Phase One, as they're basically the only up-to-date and modern option if you prefer a leaf lens camera system. The average Jill or Joe isn't going to spend that kind of money.

Usage/what people shoot: Relatively few photographers are photographing wind surfers, boogie boarders, snow boarders, gymnasts, etc., in an action portraiture context ((e.g. action fashion/lifestyle/ glamour, etc.) as opposed to just a sports context in ambient light, specifically outdoor ambient lighting. so they don't need the high shutter speed + flash while shooting in outdoor ambient light. I stress the word action and outdoor ambient light.

Example (below): Katelyn Ohashi (UCLA Gymnast) action nudes for an ESPN issue.

https://www.dailymail.co.uk/femail/...i-poses-naked-ESPNs-September-Body-Issue.html

Her bio: https://en.wikipedia.org/wiki/Katelyn_Ohashi

Using her action photos to illustrate (in general) that these types of photos underscore two important areas where "equipment matters"... and can matter a lot.

(1) lack of resolution - it can be aesthetically detrimental to be in a position where you have to put some distance between you and the subject and then in post, can't crop in to get the desired composition, or print large enough where the subject isn't the size of a chickpea, which would be a non-issue with far more pixels at one's disposal. While such ins't isn't an issue for many photographers, It is for many others. I don't know what camera was used, but the photographs that I've seen, she looks rather small.

(2) subject blur - many times HSS doesn't have the power that allows placing strobes at a distance and still getting a lot of light on the subject when the lens is stopped down. (a) HS (hyper sync / long-burn flash) often requires fiddling with the 'timing' of the flash in order to find the 'sweet spot' and HSS can be too weak ... I don't enjoy finding the sweet spot on one camera, only to put down a Pentax and pick up a Canon, and have to fine tune the timing again. (b) I can only use one outlet on a Broncolor MOVE pack when using HS... things like that. (c) have to stop what I'm doing and select HS mode - I just want to be able to use whatever shutter speed I want and the flash light up the subject.

Subject blur can be had at 1/1600.. so how much blur is wanted for a particular aesthetic (say, hand/arm/leg motion) result, can dictate shutter speed, while the shutter speed remains relatively fast to freeze other things in the frame such as no blurring of the hair or face.

Sure, I've made it work - but It's FAR easier to use a leaf shutter lens that allows 1/1600th shutter speed or faster, and photograph what I need at f/11-f16 without having to consider anything... without fine tuning anything - where I don't have to be mindful of the flash or pack's power setting (HS generally requires higher power settings).

I get more light with HS over HSS (half a stop or more can be had), and the most light on the subject easily with a leaf lens.

Some of the older Hasselblad (H and 500 series), Pentax (75mm leaf lens), etc., leaf lenses weren't worth bothering with in my use case because they only allowed 1/500th or 1/800th max shutter speed, which is practically worthless for even semi-freezing flung sand (beach), water spray (beach) or powder (snow boarders, etc.) ... it's just too slow of a shutter speed to me.

After all, today there are 600, 1000, even 1200 Ws monolights that feature HSS, and common lighting setups often involve more than one such flash. I realize that HSS reduces light output, and that modifiers like softboxes and umbrellas reduce it further.

I think of HSS/HS both as less-than-optimal solutions when compared to a decent leaf shutter lens. I cannot attest to the latest HSS systems (e.g. Broncolor's newest SATOS packs, etc.) Modifiers and lens filters can sap the life out of HSS. Many people will shoot at or nearly wide open with strobe(s) 6-9 ft. away from the model and exclaim HSS is wonderful... well... that's not going to be everyone's story and budding photographers should always first ask about the recommending photographer's shoot particulars... distance to the subject, modifiers used, shutter speed, aperture, iso, power setting of the strobe/power pack, location of the sun in reference to the subject, etc..

But would, say, a kit with two or three Godox AD600Pro monolights allow you to light adequately and to your taste, where you have to balance with outdoor daylight, using HSS instead of X-sync or a leaf-shutter lens?

Yes. It probably would. However the problem remains ... too little power and the required multiple lights to get what I want. When I'm on a hot beach, I don't want to have to drag lights here and there.. especially over wet, slick, large rocks - I'm long done with doing all of that, but the point remains. I'd rather plug in a strobe, and immediately be able to run my shutter speed up to say, 1/1600th and get a lot of light in the center of the frame.

For shooting outside with strobes, there is no better solution compared to using a fast , high quality leaf lens. Not even close in my experience. Again, this is just my opinion.

** One of the best practical benefits of leaf lenses is that no matter what kind or brand of strobe you use, it's always going to work at higher shutter speeds. Using your grandpa's strobe from the 80's? It'll work. Using a Canon/Nikon/Metz/Pentax/obscure brand speedlight? They'll always work on or off camera and irrespective of their power setting. Want to have several people handhold speedlights in different positions following your model/subject while you shoot 1/1,000th shutter speed? No problem. Cross brands? You want to use an old Alien Bee, Speedotron, Broncolor, Profoto or Godox studio strobe with your new Hasselblad or Phase One at 1/1600th shutter speed, in the middle of the day getting beach volleyball portraits? - no concern. It just works.

Try that with a Fuji GFX, or your Nikon/Canon/Pentax/Sony.. So much more latitude with the leaf lens.

https://www.captureintegration.com/...t=In Phase One 645 bodies,the FPS at 1/4000th.

Good post/ good questions!

--
Teila K. Day
http://teiladay.com

 

[BillNi]

What is your practical experience regarding whether monolights or even shoe-mount flashes with high-speed sync (HSS) suffice in place of leaf-shutter lenses (which can sync at any shutter speed) in situations where you need to balance relatively bright ambient light with flash lighting on the main subject at large or moderate apertures?

Apertures f/2.8 and larger, 1/500th shutter, and the light(s) a 10ft. away from the subject at 100 iso? HSS can effortlessly offer a nice blend of "pop" to the subject when the sun is in front of ... all the way to 90 degrees to the side of the subject. Start closing the aperture (smaller), add modifiers, filters, the sun more behind the subject in the middle of a bright day, and push the shutter speed up to 1/1600 or more and power becomes an issue fairly rapidly, especially when you start moving the lights further away from the subject.

All sounds very reasonable yet misleading.

HSS light is effectively a continuous source and all camera settings affect it exactly the same as they affect continuous ambient light. The only things affecting the blend between some given ambient light and HSS flash light are flash power, flash to subject distance, and flash modifiers.

HSS does not run out of power at faster shutter speeds or smaller apertures it runs out of power at higher ambient levels which also caused you to reduce aperture and/or increase shutter speed.

 

[BillNi]

Colin Creevey wrote
I did a test with images on another thread using an AD600Pro. My results mirrored those found on a Youtube video talking about power loss of using HSS on various products. That is, the AD600Pro lost 1.5 stops from going from non-HSS to HSS. And before you ask, yes this is not including the drop due to shutter speed.

If we take a shot without HSS at ISO 100, f4, 1/100 then according to you we should only see an exposure lost of 1/3 or 1/2 stops if we take another frame with HSS enabled. ISO 100, f2, 1/400. We have countered the 2 stops of light lost from SS by opening the aperture up 2 stops. However, as I showed in my test with images, it is closer to 1.5 stops given the parameters I was testing.

I posted yesterday the result of my test with a V860II and HSS at 1/400 which was 2 1/3 stops down. I just did the same test with an AD600 pro and it was 2 stops down from which I would assume the AD600Pro is a bit more efficient and/or the HSS pulse is a bit less than 1/100th.

The only way I would believe less than 2 stops down is if you were chopping off some of the tail of the non-HSS reference shot. The AD600Pro flash duration (t 0.1) is 1/220th at full power and you probably have some wireless trigger delay so a lot of cameras have sync speeds too fast for that.

 

[Colin Creevey]

Colin Creevey wrote

I did a test with images on another thread using an AD600Pro. My results mirrored those found on a Youtube video talking about power loss of using HSS on various products. That is, the AD600Pro lost 1.5 stops from going from non-HSS to HSS. And before you ask, yes this is not including the drop due to shutter speed.

If we take a shot without HSS at ISO 100, f4, 1/100 then according to you we should only see an exposure lost of 1/3 or 1/2 stops if we take another frame with HSS enabled. ISO 100, f2, 1/400. We have countered the 2 stops of light lost from SS by opening the aperture up 2 stops. However, as I showed in my test with images, it is closer to 1.5 stops given the parameters I was testing.

I posted yesterday the result of my test with a V860II and HSS at 1/400 which was 2 1/3 stops down. I just did the same test with an AD600 pro and it was 2 stops down from which I would assume the AD600Pro is a bit more efficient and/or the HSS pulse is a bit less than 1/100th.

Just to be clear, you are talking a total of 2 1/3 stops for the V860II and 2 stops for the AD600Pro is total including the loss from shutter and not adjusting any other settings? Or is that 2 stops just from entering HSS?

If the it's the first (including shutter loss) then please upload your tests because they contradict what I tested (and uploaded). Also please fill me in on your testing methodology.

As mentioned in my previous post, the 1.5 stops I measured were from entering from HSS only, nothing to do with shutter speed.

The only way I would believe less than 2 stops down is if you were chopping off some of the tail of the non-HSS reference shot. The AD600Pro flash duration (t 0.1) is 1/220th at full power and you probably have some wireless trigger delay so a lot of cameras have sync speeds too fast for that.

 

[Colin Creevey]

To try to be clear, I was not and am not asking about how HSS works. That's not even relevant to what prompted me to start the topic.

I'm asking people who actually use HSS with monolights and/or shoe-mount flashes how often, if ever, they run into the problem of not having enough light output when in HSS mode, where they would have enough light output if they could X-sync. Obviously if you run out of light output in HSS mode, but you would have enough light output if you could X-sync, then a leaf shutter would benefit you--which was my original point of interest.

Well leaf shutter is one option but I keep going back to NDs. If you are not trying to capture a subject in motion, the use of an ND is still valid to lower ambient. There are other factors involved and I am making the assumption you are shooting mirrorless not DSLR.

Thanks!

 

[Colin Creevey]

Like a way to demonstrate the difference in exposure between a flash in standard and HSS mode, because we changed the shutter speed of a camera with a focal plane shutter from its X-sync speed to 1/3rd of a stop shorter (I.e., from 1/200th to 1/250th)…

if only we had the tools available to stage a demonstration and share the methodology so anyone can repeat it…

If only…

Serious or ironic?

I just repeated a test I did a while ago. Camera on tripod, darkened room, Godox V860II in the hot shoe bounced from the ceiling. Shutter below sync speed, flash non-HSS set to full power, and F8 gave a reasonable exposure.

Then switched to HSS and 1/400th shutter. I predict it will need 2 1/3s stops more exposure to produce the same image brightness. 2 stops because the sensor only sees 1/4 of the 1/100th second HSS pulse and 1/3 for HSS losses. As predicted F3.5 gave an image with the same brightness.

Images with metadata or did not happen.

 

[Colin Creevey]

Like a way to demonstrate the difference in exposure between a flash in standard and HSS mode, because we changed the shutter speed of a camera with a focal plane shutter from its X-sync speed to 1/3rd of a stop shorter (I.e., from 1/200th to 1/250th)…

if only we had the tools available to stage a demonstration and share the methodology so anyone can repeat it…

If only…

I did one a couple weeks ago. I encourage others to point out any flaws in my testing methodology and to repeat the experiment with their own gear.

https://www.dpreview.com/forums/post/67187903

 

[BillNi]

Just to be clear, you are talking a total of 2 1/3 stops for the V860II and 2 stops for the AD600Pro is total including the loss from shutter and not adjusting any other settings? Or is that 2 stops just from entering HSS?

If the it's the first (including shutter loss) then please upload your tests because they contradict what I tested (and uploaded). Also please fill me in on your testing methodology.

As mentioned in my previous post, the 1.5 stops I measured were from entering from HSS only, nothing to do with shutter speed.

My previous post said:

just repeated a test I did a while ago. Camera on tripod, darkened room, Godox V860II in the hot shoe bounced from the ceiling. Shutter below sync speed, flash non-HSS set to full power, and F8 gave a reasonable exposure.

Then switched to HSS and 1/400th shutter. I predict it will need 2 1/3s stops more exposure to produce the same image brightness. 2 stops because the sensor only sees 1/4 of the 1/100th second HSS pulse and 1/3 for HSS losses. As predicted F3.5 gave an image with the same brightness.

I don't think simply turning HSS on and off is a reliable test. I don't have a camera which lets me go above sync speed when an intelligent flash/trigger is attached and not in HHS mode. The camera can't stop me turning on HSS on the flash but that doesn't mean below its sync speed it uses HSS timing. When I tried I saw a top to bottom gradient which suggests non-HSS sync timing was used. So it is likely messed up and will still depends on the shutter speed used relative to the 1/100th HSS pulse length.

 

[Gato Amarillo]

To try to be clear, I was not and am not asking about how HSS works. That's not even relevant to what prompted me to start the topic.

I'm asking people who actually use HSS with monolights and/or shoe-mount flashes how often, if ever, they run into the problem of not having enough light output when in HSS mode, where they would have enough light output if they could X-sync. Obviously if you run out of light output in HSS mode, but you would have enough light output if you could X-sync, then a leaf shutter would benefit you--which was my original point of interest.

Thanks!

OK. I find HSS fairly limited with my Godox flashes -- TT350 and TT685 on Panasonic. I have enough light for portrait work so long as the flash is in fairly close - say 6 - 8 feet - but run into overheat problems unless I remember to pace myself.

I generally just stop down as needed. I can always adjust the background in post.

FWIW, the flashes seem considerably more efficient in TTL than with manual settings, but I have not tested enough to say anything specific.

At one time I kept a Panasonic FZ1000 with leaf shutter for outdoor portraits, but retired it after a year or so.

Gato

--
People: Portraits, fantasy, cosplay (mildly NSFW)
https://www.instagram.com/jrsprawlsphoto/
.
Personal pictures, road trips, rural nostalgia, and kitty cats:
https://www.instagram.com/j.r.sprawls/

 

[Colin Creevey]

Just to be clear, you are talking a total of 2 1/3 stops for the V860II and 2 stops for the AD600Pro is total including the loss from shutter and not adjusting any other settings? Or is that 2 stops just from entering HSS?

If the it's the first (including shutter loss) then please upload your tests because they contradict what I tested (and uploaded). Also please fill me in on your testing methodology.

As mentioned in my previous post, the 1.5 stops I measured were from entering from HSS only, nothing to do with shutter speed.

My previous post said:

just repeated a test I did a while ago. Camera on tripod, darkened room, Godox V860II in the hot shoe bounced from the ceiling. Shutter below sync speed, flash non-HSS set to full power, and F8 gave a reasonable exposure.

Then switched to HSS and 1/400th shutter. I predict it will need 2 1/3s stops more exposure to produce the same image brightness. 2 stops because the sensor only sees 1/4 of the 1/100th second HSS pulse and 1/3 for HSS losses. As predicted F3.5 gave an image with the same brightness.

I don't think simply turning HSS on and off is a reliable test. I don't have a camera which lets me go above sync speed when an intelligent flash/trigger is attached and not in HHS mode. The camera can't stop me turning on HSS on the flash but that doesn't mean below its sync speed it uses HSS timing. When I tried I saw a top to bottom gradient which suggests non-HSS sync timing was used. So it is likely messed up and will still depends on the shutter speed used relative to the 1/100th HSS pulse length.

What camera did you use? How did you evaluate "same brightness." Did you use a light meter or were you just eyeballing it on the LCD screen on the back of the camera. Where are images with metadata. Words in this context mean little without something to back it up. Why? Because there is evidence that contradicts your statement.

 

[BillNi]

I just repeated a test I did a while ago. Camera on tripod, darkened room, Godox V860II in the hot shoe bounced from the ceiling. Shutter below sync speed, flash non-HSS set to full power, and F8 gave a reasonable exposure.

Then switched to HSS and 1/400th shutter. I predict it will need 2 1/3s stops more exposure to produce the same image brightness. 2 stops because the sensor only sees 1/4 of the 1/100th second HSS pulse and 1/3 for HSS losses. As predicted F3.5 gave an image with the same brightness.

Images with metadata or did not happen.

Why? The results are similar to your experiment in the other HSS/ND thread.

You took a full power non-HSS shot probably enough below sync speed then turned on HSS and set 1/320th shutter.

I predict you lose 1 2/3 stops because your sensor sees a little less than 1/3rd of the HSS pulse. I'll assume the AD200 like the AD600 I tested today doesn't lose an extra 1/3rd.

I predict 1 2/3rds and you added 1 and another 0.5 in post. 0.17 stops out - near enough for me.

 

[BillNi]

What camera did you use? How did you evaluate "same brightness." Did you use a light meter or were you just eyeballing it on the LCD screen on the back of the camera. Where are images with metadata. Words in this context mean little without something to back it up. Why? Because there is evidence that contradicts your statement.

I looked at the cameras histogram and confirmed the best match by looking at exposures 1/3rd stop either side.

Your evidence confirms not contradicts my theory and findings.

 

[NAwlins Contrarian]

Source: https://fstoppers.com/lighting/demystifying-high-speed-sync-68527

Let me be clear: I'm not asking about how HSS works. I know how HSS works. I'm asking people who use HSS with monolights and/or shoe-mount flashes how often, if ever, they run into the problem of not having enough light output when in HSS mode, where they would have enough power if they could X-sync.

This is how I understood your original question and it is hard to answer generically as the subject matter and way of shooting is going to be different for multiple people.

I knew one local tog that had issues with output from a Godox AD1200Pro at full power under sync speed. However for me, I doubt I would never shoot what he was shooting and therefor wouldn't have that issue.

Were you just asking for interest or for personal advice?

I am interested / curious about the range of experience of the participants here. The idea was to get something of a sampling of responses about whether HSS has pretty much made leaf shutters unnecessary. What kicked off my inquiry was a question in the Medium Format Talk forum, "I wonder why Fuji doesn't offer at least 1 LF lens for portrait users like me who use strobes for almost 100% of their shots." I responded with my suspicion: "I suspect that the increasingly-frequent ability of increasingly-powerful strobes to provide 'high-speed sync' (HSS) makes leaf shutters less and less necessary." I figure some of the folks here could report their relevant experiences.

 

[NAwlins Contrarian]

To try to be clear, I was not and am not asking about how HSS works. That's not even relevant to what prompted me to start the topic.

I'm asking people who actually use HSS with monolights and/or shoe-mount flashes how often, if ever, they run into the problem of not having enough light output when in HSS mode, where they would have enough light output if they could X-sync. Obviously if you run out of light output in HSS mode, but you would have enough light output if you could X-sync, then a leaf shutter would benefit you--which was my original point of interest.

Thanks!

OK. I find HSS fairly limited with my Godox flashes -- TT350 and TT685 on Panasonic. I have enough light for portrait work so long as the flash is in fairly close - say 6 - 8 feet - but run into overheat problems unless I remember to pace myself.

Thanks for a helpful and interesting response. It sounds like, as a practical matter, for your use, HSS provides enough light output, but because it uses more energy, you find your flash overheating limits how fast you can shoot.

I generally just stop down as needed. I can always adjust the background in post.

That has been my past practice, but I don't even own an HSS-capable shoe flash or monolight. I'm considering buy a Godox 685 to go with my camera, but I'm wondering how often it would provide me much benefit. Looking at some old shots with a previous camera, X-sync limited me to 1/160 s, which required me to stop down to f/8--not ideal, not awful. The replacement camera will x-sync at 1/250 s, so in similar circumstances I could use f/6.3. If I could pick any aperture I wanted, it would probably be f/4 to f/5.6, so HSS would help a little, but not a huge amount.
(And FWIW, sometimes I've adjusted the background in post, but usually I find that not quite as nice looking, and sometimes a bit laborious, although newer software masking tools are making it less so.)

 

[NAwlins Contrarian]

Thanks, you're exactly the sort of upper-level, frequent location shooter whose experience most interests me. You raise several points to digest, but if you'll indulge a couple more questions:

As I recall, you're a Pentax 645Z shooter. I know Pentax has offered some leaf-shutter lenses that will work with the 645Z, although I don't recall any of them being modern auto-focus lenses. You mention the Pentax 645 75mm LS being limited to 1/500 s. Is there a viable (for your uses) Pentax 645 LS lens, and if so, do you use it sometimes?

If not, did you decide to live with the compromises and limitations HSS imposes, instead of gaining only two or three stops versus the 645Z's x-sync?

I get that today and in the recent past, leaf-shutter lenses for interchangeable-lens cameras have mostly been limited to top professional systems. But the question that started this off was why Fuji hasn't offered any leaf-shutter lenses for the GFX system, so although that's not Phase One territory, most of the users are serious enough photographers, and big enough spenders, to make a GFX leaf shutter lens or two economically viable for Fuji--if HSS hasn't replaced most of their uses.

Thanks!

 

[Colin Creevey]

I just repeated a test I did a while ago. Camera on tripod, darkened room, Godox V860II in the hot shoe bounced from the ceiling. Shutter below sync speed, flash non-HSS set to full power, and F8 gave a reasonable exposure.

Then switched to HSS and 1/400th shutter. I predict it will need 2 1/3s stops more exposure to produce the same image brightness. 2 stops because the sensor only sees 1/4 of the 1/100th second HSS pulse and 1/3 for HSS losses. As predicted F3.5 gave an image with the same brightness.

Images with metadata or did not happen.

Why? The results are similar to your experiment in the other HSS/ND thread.

I don't believe the results are similar at all. I'm not sure how I can correct your understanding because I cannot identify where you have gone wrong.

In my experiment, I demonstrated the power lost is equal to 1.5 stops + X stops based off shutter.

You are saying you only loose 1/3 of a stop, which is significantly different.

You took a full power non-HSS shot probably enough below sync speed then turned on HSS and set 1/320th shutter.

I predict you lose 1 2/3 stops because your sensor sees a little less than 1/3rd of the HSS pulse. I'll assume the AD200 like the AD600 I tested today doesn't lose an extra 1/3rd.

I predict 1 2/3rds and you added 1 and another 0.5 in post. 0.17 stops out - near enough for me.

No, this is wrong. I added 1.5 in post. So 1.5 stops was lost due to being in HSS. The amount of light lost from shutter speed was countered by opening the aperture up proportionally.