watersedge Loc: Bristol UK

High speed sync - is that only designed for fill flash or is it meant to be used for high shutter speeds up to 1/250 in any situation where I need a flash

Is it worth using the plus or minus on the flash exsposure compensation or better doing it in software and ill be using RAW. Ill be using bounce flash with a defuser

CO

High speed sync is designed for shutter speeds faster than the sync speed of your camera. You can use it in any situation. With Nikons you would select one of the Auto FP modes. I don't know what other manufacturers call it. It pulses the flash on and off quickly (thousands of times per second).

I use flash compensation all the time when using my speedlights. I often dial in negative flash compensation to get some fill light without the harsh flash look. If you're doing bounce flash though, you need all the power you can get since the flash power is diminished considerably by bouncing off the ceiling or walls.

Tomfl101 Loc: Mount Airy, MD

High speed sync allows for shutter speeds above your camera’s maximum (200-250 on most cameras). It works by lengthening the flash burst duration so as to be “on” throughout the shutters swing across the sensor plane. The advantage is to allow for super high shutter speeds and or extra wide apertures in bright sunlight. It does come with the cost of using full power most of the time so recycle time is very slow.
The second part of your question is not really related to high speed sync exclusively but yes you can use +- controls with HSS as long as you are not dumping full power.

Notorious T.O.D. Loc: Harrisburg, North Carolina

With my Canon Speedlites you can leave them in High Speed Sync all the time and they will not use it if you are at or below the sync shutter speed. If above it goes to HSS.

I believe in HSS they pulse light about 30,000 times per second. HSS loses a couple stops of power though and will reduce the effective distance of the flash. Best to only go above sync speed if you need to in my view.

speters Loc: Grangeville/Idaho

You can't do flash exposure compensation in pp, you use it depending on your situation, it has nothing to do with the exposure in the camera! HSS is not only for fill, but you use it whenever the needs arrive! And you can use it with any shutter speeds (1/8000 for ex.)!

jdubu Loc: San Jose, CA

HSS is not just for fill flash. You could use it to keep ambient lit backgrounds from blowing out and having your flash be the key light. Remember, bouncing and using a diffuser lessens your final light output.

Sometimes, you will need more power than one speedlight with HSS can provide to overpower the ambient lighting. You can double, triple or quadruple your flashes.

gvarner Loc: Central Oregon Coast

Check out this video for proper TTL flash use indoors. Outdoors you can use high speed sync to reduce the brightness of a background lit by ambient light. Just remember that when using flash, there are two sources of light - the flash and ambient light. In camera Manual mode, the flash controls light on the subject depending on the aperture setting and the ISO affects the reach of the flash. The shutter speed regulates the amount of ambient light that shows up in the photo but has no impact on the exposure of the subject. The flash does all of that work.

https://www.youtube.com/watch?v=wLeaX_WXUJ8

Notorious T.O.D. Loc: Harrisburg, North Carolina

Could you expound on what you mean in the last 3 sentences of your post. Are you talking using TTL only and not manual flash? I’m a little confused...

nadelewitz Loc: Ithaca NY

Very interesting. I did not know this. Is it true with all Canon cameras and Speedlites? I have a 60D and a 420EX.

amfoto1 Loc: San Jose, Calif. USA

Using bounce AND a diffuser will waste much of the light output of your flash. Direct flash with a diffuser (or even without) is the most efficient and can look great when the flash is positioned properly... Usually is best with the flash mounted on a bracket that raises it above the camera and off to one side, to minimize redeye and throw shadows down and behind the subject. To use a flash bracket that way requires an off-camera shoe cord or a wireless controller of some sort (depends on the flash).

High Speed Sync (HSS) "times" the flash and shortens it's duration to allow it to be used with shutter speeds faster than your camera's sync speed (sounds as if it's 1/250, in your case.... but it varies by camera model). HSS can be use with either "Fill" or "Full" flash.

HOWEVER... HSS greatly reduces the distance your flash can reach. The faster the shutter speed, the more the distance will be reduced.

Besides, you may not need a fast shutter speed with flash. If you're using "Full" flash, it can act like a fast shutter speed, regardless of what's set on the camera. The brief duration of the flash typically "acts like" a shutter speed of 1/720 or faster. What gets tricky is when you mix ambient light and flash... either as "Fill" or using "Full" with a slow shutter, large aperture and/or higher ISO that will record a lot of ambient light too. Especially with moving subjects this can cause "ghosting", where sort of a double image is recorded. This is where another feature of flash becomes important... Rear Curtain Sync. It's used at slower shutter speeds (think of it as the opposite of HSS), so that the ghosting appear behind the moving subject and looks "normal"... rather than making them look like they are going backward.

Below is an example where I used 1/30 shutter speed and strong fill flash with Rear Curtain Sync, panning with a moving subject:



Flash Exposure Compensation (FEC) is just like Exposure Compensation (E.C.) that's done without flash, except of course FEC is done with the flash.

E.C. is used to override auto exposure to compensate for situations where the camera's metering system will want to under or over-expose. The camera's metering system has no idea what it's being pointed at and it tries to make everything "average gray". This works out pretty well a lot of the time, because most scenes have a variety of tonalities that average out pretty close to that "18% gray".

HOWEVER... If you are shooting a scene that's not average tonality.... or if you are using a narrow metering pattern such as Spot that's reading of a small area that's not average tonality... E.C. is used to correct for what the metering system will want to do. For example, if you're photographing a bride in a white gown in a snow scene... much of the scene is light toned.. the camera will want to under-expose to "make everything gray", so you need to dial in some + E.C. Or, say you're taking a shot of a black bear in a coal mine... the camera will want to over-expose to "make everything gray", so you need to dial in some - E.C.

E.C. only applies to all the Auto Exposure (AE) modes: Aperture Priority AE, Shutter Priority AE, Program AE and Auto ISO with Manual (which is actually also an AE mode).

There's no E.C. used with Manual mode (no Auto ISO). With that, you can simply bias your settings for similar corrections, if needed.

Now, flash can be Auto Exposure or Manual (as well as "Fill" or "Full"). Nikon calls AE flash "iTTL". Canon calls it "ETTL". I have no idea what others call it.... you'll have to look it up.

When AE flash is used, a camera set to Manual (no Auto ISO) is still Auto Exposure.

FEC is used the same way as E.C., except now it's being done to adjust the flash's output. It can be used as described, to "correct" for metering bias. Or it can be used simply to increase or decrease the appearance of flash in the image.

Finally... "Fill" versus "Full": I don't know what system you're using or if all systems are the same as the Canon I use. But, basically, any time flash is used with a Canon camera that's set to any AE mode, it will automatically act as "Fill"... where the image is taken using a combination of ambient light and light from the flash. The camera will read the ambient light and set the exposure accordingly.... And the flash is fired at reduced power to open up the shadows, add catchlights and generally "enhance" ambient light. Usually the power reduction is approx. -1.66 stops, but this can be over-ridden and increased or decreased using FEC. (EC also can be used to "tweak" the ambient light exposure.)

On my Canon cameras, to make a flash fire "Full", all I have to do is switch the camera to Manual exposure mode. So long as the flash is set to ETTL, this is actually still an auto exposure mode. Except now the camera's metering system is only considering the flash, treating it as the primary light source. You can set the camera's ISO, shutter speed and lens aperture so that the general scene will "go dark" and it's mostly just the flash illuminating the subject.... Or you can adjust the camera's ISO, shutter speed and lens aperture to incorporate more of the ambient light in the image, along with the flash. If wanted, FEC can be used too, since this is still a form of AE. (E.C. won't be available, because the camera is set to Manual. But if they wish the user can still tweak things by adjusting aperture, shutter and/or ISO.)

One thing to note... for flash auto exposure (iTTL, ETTL or similar) the way many modern cameras take meter readings with flash is by firing a "pre-flash". This is a very low-powered flash - typically about 1/64 power - that's metered to determine the power level of the "real flash", which is fired a fraction of a section later. Usually these two "pops" happen so fast that the user doesn't realize it's happening.... it seems like a single "pop" of the flash. However, it can cause problems if using multiple flashes that are being optically triggered... that are set to fire whenever another flash goes off. It can cause those other flashes to fire too early, causing an incorrect reading by the meter and under-exposed images.

I use auto flash (ETTL on my Canon gear) all the time when I'm shooting "on the run", both Fill and Full. I find it works well, though it does force me to slow my shooting and wait for the flash(es) to recycle at times.

I usually only switch to Manual flash when working in-studio, under very controlled setups. (Often in combination with studio strobes, which are purely manual.)

Finally, I tend to avoid "bounce" flash. Too often with bouncing there are variables out of my control... such as the distance to and color of the object. Plus it wastes light massively, which in turn forces the flash to fire more fully, causing it to recycle much more slowly and drain batteries a lot faster. To minimize these issues, in the past I've used a "bounce card" that mounts to my flash. This adds a lot of bulk, though, and is easily damaged. In studio, I also "bounce" flash (or strobes) out of umbrellas at times, for a nicely "muted" form of light. But, more often than not, I use flash direct... frequently with a diffuser of some sort.

gvarner Loc: Central Oregon Coast

Camera in Manual mode, flash in TTL mode. For indoors, start with 1/200, F4.5, ISO 400. Change the F stop to affect DoF or the ISO to give the flash a bit more reach. For outdoors, pretty much the same thing but set your camera to use high speed sync and increase shutter speed to darken bright backgrounds. I can use up to 1/8000 on my D7200 if I want to make the background really really dark. Do trial and error for the effect you want.

Weddingguy Loc: British Columbia - Canada

It works by lengthening the flash burst duration so as to be “on” throughout the shutters swing across the sensor plane.
This statement above is incorrect. It does not lengthen the flash duration, but caused multiple flash bursts that match the progression of the two curtains of the shutter.

Notorious T.O.D. Loc: Harrisburg, North Carolina

Ok I understand what you are saying now... Thanks.

Weddingguy Loc: British Columbia - Canada

Is it worth using the plus or minus on the flash exsposure compensation or better doing it in software and ill be using RAW. Ill be using bounce flash with a defuser[/quote]

Under or over exposing an image greatly deteriorates the quality of the image and cannot be compensated for in PP. So the answer to your question is "no", you cannot use PP to replace the FEC (Flash Exposure Compensation) feature.

Notorious T.O.D. Loc: Harrisburg, North Carolina

I would think it would work the same, but I have 600RT Speedlites and 1Dx2 body. Just turn on HSS and give it a try at say 1/100 and 1/500 shutter speeds. It will either fire the Speedlite or not at 1/100 and HSS. It should fire at 1/500 with HSS. I am assuming both the body and Speedlite support HSS.