Flash sync speed really matter?

[wooster]

I'd be interested to hear from people on whether they feel the lower flash sync speed found on the Canon 5D mk3 and the Nikon D600 of 1/200s is really so different from the slightly higher speed of 1/250s of the D800?

Seems to me the people most affected by this would be wedding togs and they happily been using 5Ds of various ages with this limitation.

I am not convinced the difference would be significant but I'm happy to hear why I'm wrong

 

[Phil V]

You're not wrong, especially as nowadays we all use guns with HSS and in the studio the higher flash sync speeds are generally not trusted and we tend to use 1/125.

It's an academic difference unless you really need to pull every ounce from your gear, which of course someone will now explain.

 

[Calzor Suzay]

An apt read

 

[wooster]

Thanks folks for the replies. Good link to NVM's site

Seems the 1/200 is not such a big deal. I wondered because David Hobby has got the hump about it over on the strobist site

http://strobist.blogspot.co.uk/2012/09/nikon-d600-think-twice-before-you-jump.html

Sorry don't know how to work the "link machine"

 

[Garry Edwards]

Sync speed matters when shooting outdoors in bright light - but exactly what are we looking at here? Just 25%, or 1/4 stop. It's nothing.

If it's your perception that that tiny amount is making a tangible difference, just buy a more powerful flash

 

[wooster]

There seems to be agreement among us. It's no big deal. This was my original view but I wondered if I was missing something or not

 

[saracenhouse]

I think some folks can get a little confused by what the sync speed really is or does. I know many times in the studio, I have had the conversation with customers that are surprised that I suggest they shoot at 1/125th and concerned that they think they should be shooting at a faster speed.

For those that don't know, the sync speed is just the duration of the window that the camera captures the image, the shutter speed, in the studio, in effect becomes the duration of the flash firing (in our case it's 1/2500th second) and as its a blackout studio, there's no real ambient light to worry about, even with the modelling and house lights on full blast when shooting at apertures of around f/11.

But as Garry says, where it becomes an issue, is when balancing flash and other light sources, where being able to shoot at higher sync speeds can be really useful (eg with a Pocket Wizard etc)

 

[HoppyUK]

There seems to be agreement among us. It's no big deal. This was my original view but I wondered if I was missing something or not

It only matters outdoors, but then it can make a big difference.

Mention of Pocket Wizards above is a case in point. Their Mini/Flex system can tweak the exact x-sync moment to take up any slack in the manufacturer's nominal setting.

For example, Canon 7D has a 1/250sec x-sync as standard, but PW can get that up to 1/400sec (up to 1/500sec on a Canon 1DMk4). That's a very useful increase over standard, almost one stop higher than stock. In bright daylight, one stop of extra shutter speed translates to an effective doubling of the flash power.

 

[Steve Smith]

Just 25%, or 1/4 stop. It's nothing.

Just to be pedantic, 25% would be closer to a third of a stop as stops are logarithmic and percentages are linear.

I have some cameras with a flash sync speed of 1/30 so I wouldn't use those in bright light. The best cameras for flash in daylight have leaf shutters which can sync with flash at all speeds.

the sync speed is just the duration of the window that the camera captures the image

The flash sync speed is the fastest speed in which the film or sensor is fully exposed to light over all of its surface. At higher speeds the second curtain starts to close before the first curtain has fully opened which is why you get a black bar if you try to use too fast a speed. The black bar is the shutter curtain in the way.


Steve.

 

[Garry Edwards]

You're right of course, pedant or not. But a 3rd of a stop is still pretty well nothing in the scheme of things - when low powered flash is added to daylight, the effects aren't dramatic and moving the flash just a tiny bit closer to the subject can do a lot to the effective power, without the harshness becoming tangible. I've used a lot of old cameras with 1/30th synch speed, and managed.

Or, as I said, just use a more powerful flash.

 

[saracenhouse]

The flash sync speed is the fastest speed in which the film or sensor is fully exposed to light over all of its surface. At higher speeds the second curtain starts to close before the first curtain has fully opened which is why you get a black bar if you try to use too fast a speed. The black bar is the shutter curtain in the way.


Steve.

As I said, the window of time that the camera captures the image. You're not capturing an image if the curtain is half way over the frame

 

[Steve Smith]

As I said, the window of time that the camera captures the image. You're not capturing an image if the curtain is half way over the frame

You are quite right. I was just describing the way the shutter curtains work for anyone who wasn't sure and might wonder why they get a black area if they use a faster shutter speed.


Steve.

 

[lucky_13]

Sorry to hijack the thread but just out of curiosity if I was to shoot the Notting Hill carnival with a 58 guide number speedlite f5.6 and a 1/200 shutter speed would that be fast enough to not overexpose the background or would I need to purchase a HSS Speedlite in order to shoot at 1/500 or so? Or should I just stop down the aperture to lets say f11 or so?

 

[Phil V]

Sorry to hijack the thread but just out of curiosity if I was to shoot the Notting Hill carnival with a 58 guide number speedlite f5.6 and a 1/200 shutter speed would that be fast enough to not overexpose the background or would I need to purchase a HSS Speedlite in order to shoot at 1/500 or so? Or should I just stop down the aperture to lets say f11 or so?

I'd assume the flashgun would either have adjustable manual settings or some kind of auto setting in order to give some flexibility to the exposure?

 

[lucky_13]

I'd assume the flashgun would either have adjustable manual settings or some kind of auto setting in order to give some flexibility to the exposure?

I was thinking of getting a yongnuo yn 560 III

 

[Richard King]

I have a D70 that syncs at 1/500 that I can push even further if I do the electrical tape trick!

 

[Steve Smith]

I have a D70 that syncs at 1/500 that I can push even further if I do the electrical tape trick!

What is this trick?


Steve.

 

[HoppyUK]

What is this trick?


Steve.

Never done it myself, but some older DSLRs with CCD sensors used electronic switching at higher shutter speeds, instead of mechanical focal plane (Nikon D70/D40, Canon 1D, some Canon G-series too I think).

But their top speeds were capped when using flash, to avoid clipping the flash pulse at highest shutter speeds, ie when flash duration is longer than the shutter speed.

But if you tape over the communication pins in the hot-shoe and just leave the central firing pin (or use a non-communicating gun) then the camera doesn't know there's a flash attached and will deliver an x-sync triggering signal at all speeds.

 

[Steve Smith]

Seems strange that the higher speeds were restricted rather than being sold as a feature.


Steve.

 

[HoppyUK]

Seems strange that the higher speeds were restricted rather than being sold as a feature.


Steve.

Because of the exposure problem when shutter speed is shorter than the flash duration. And also I suspect because of sync timing tolerances when trying to tie up a say a 1/8,000sec flash duration with a 1/8000sec shutter speed.

 

[EOS_JD]

Sorry to hijack the thread but just out of curiosity if I was to shoot the Notting Hill carnival with a 58 guide number speedlite f5.6 and a 1/200 shutter speed would that be fast enough to not overexpose the background or would I need to purchase a HSS Speedlite in order to shoot at 1/500 or so? Or should I just stop down the aperture to lets say f11 or so?

Stop down the aperture. With HSS you can up the Shutter speed to get a good exposure - but you will lose a lot of flash power in HSS. If the subject is close you may be ok.

 

[EOS_JD]

It only matters outdoors, but then it can make a big difference.

Mention of Pocket Wizards above is a case in point. Their Mini/Flex system can tweak the exact x-sync moment to take up any slack in the manufacturer's nominal setting.

For example, Canon 7D has a 1/250sec x-sync as standard, but PW can get that up to 1/400sec (up to 1/500sec on a Canon 1DMk4). That's a very useful increase over standard, almost one stop higher than stock. In bright daylight, one stop of extra shutter speed translates to an effective doubling of the flash power.

Hoppy although the PWs in Hypersync get you above the native sync speed, are you not still losing power? Wondering how this increases flash power?

I tried this with the Quadras and you lose power the faster the SS is (although I only tried at home in a dark room exposing a white door).

 

[HoppyUK]

Hoppy although the PWs in Hypersync get you above the native sync speed, are you not still losing power? Wondering how this increases flash power?

I tried this with the Quadras and you lose power the faster the SS is (although I only tried at home in a dark room exposing a white door).

There are two kinds of hypersync with PWs - peak-HS and tail-HS (as PW describes them on their website). Quite different, and not to be confused with high-speed sync.

I was describing the former, that cunningly takes up any tolerance in the nominal x-sync timing window. There's not a lot, and it varies with different camera models, but in round numbers a typical focal plane shutter will stay fully open for about 2-3ms so there's a bit of time to be had there without clipping the flash pulse at all (assuming a speedlite will be about 1ms at full power, and often much less).

It doesn't increase flash power literally of course, but when balancing with bright daylight, one stop higher x-sync cuts the ambient by half, therefore effectively doubling the flash power.

Tail-HS only works well with a long duration flash, ie studio-type units like the Quadras (though it's poor with the faster Quadra A-type heads). It makes use of the long tail burn characteristic of studio heads (can also be usable with speedlites at full power only, before the IGBT cuts the tail off) that burns with diminishing brightness throughout the focal plane shutter's full cycle time at high speeds. In this sense it works like regular HSS, ie is effectively continuous light for exposure purposes, and therefore is affected by shutter speed.

Sorry if that's confusing, but I didn't invent the terminology

 

[EOS_JD]

makes sense - I had a couple of Quadra A heads then realised HSS was pretty much useless as the flash duration was just too fast! So I swapped an A head for an S head and can now get a reasonable HSS exposure at quite high shutter speeds.

Need to be doing some more trials with it.

 

[jonneymendoza]

My friend has an old Nikon camera thats equivalent to my old 400d and the sync speed on camera is something like 1/500. He said its because those camera's back then had a completely different mirror system that enables high sync speed when using a flash and how they do not implement that feature anymore.

 

[HoppyUK]

My friend has an old Nikon camera thats equivalent to my old 400d and the sync speed on camera is something like 1/500. He said its because those camera's back then had a completely different mirror system that enables high sync speed when using a flash and how they do not implement that feature anymore.

See post #18. Nothing to do with the mirror though, but the sensor.