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09-14-2012, 01:33 PM - 3 Likes   #1
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Why a higher Max Sync Speed matters! Please address it Pentax!

I know many of you donít like to hear those of us that complain about the slow 1/180 max synch speed of Pentax. Whenever it comes up, many say it shouldnít matter, and some say, use High Speed Synch.

For me, it's a limitation in my senior portrait photography, and my sports photography. It puts me at a disadvantage because I use Pentax. Rather than me trying to explain it poorly, I'll point to a few examples of people who can explain it better than me.

in the news today: Strobist: Nikon D600: Think Twice Before You Jump In this one, David Hobby is actually saying that the fact that the new D600 has a flash synch speed of only 1/200 makes the camera a no-go for him.

A very good explanation of why itís important is here: Flash Sync Speed

Finally, one of our forum members, Maxfield Photo, gave a good explanation of why HSS is not the answer in most cases (from this thread https://www.pentaxforums.com/forums/general-photography-industry/198557-any-f...photokina.html)

"Basically max sync speed is the fastest speed at which the shutter is fully open at any one point in time. At speeds above the max sync the second curtain starts to close before the first curtain finishes opening, so what you get in effect is an ever-narrowing slit that moves across the sensor. HSS works by pulsing the flash at a reduced power for the entire time the shutters are in motion (1/180th of a sec in Pentax's case). The problem is the narrower the size of the moving slit, the more light is wasted bouncing off the curtains, and the less light that actually reaches the sensor. HSS can usually be used at normal flash distances up to about 1/1000th, but any faster than that and you'll have to get the flash very close to the subject, or use multiple speedlights as one lightsource (you may have seen the brackets for portable softboxes that acommodate up to four flashes) HSS is great for bringing some saturation back to your skies in outdoor portraits, but contrary to what the name might suggest, it's not good for capturing fast action.

To give you some idea, my Metz 58 has a normal max working distance of 20 meters at f/2.8, ISO 100, at it's maximum zoom setting of 105mm (that's with bare bulb, no modifiers). If I cross over into HSS territory, the working distance immediately drops to
4.8 meters @ 1/250th
4.3 meters @ 1/350th
3.4 meters @ 1/500th
3.0 meters @ 1/750th
and 2.4 meters @ 1/1000th

I could keep going, but you see the distances become really small, and that's without any light modifiers, who wants that? If Pentax would increase the max sync speed, not only would we not have to engage HSS as soon, but because the shutter curtains travel faster at 1/250th, the moving slit would actually be wider at any given shutter speed, allowing more light to reach the sensor, and less to be wasted by bouncing off the curtains - essentially making HSS more efficient.

Another way to solve this problem is to introduce a hybrid shutter. Nikon did this unintentionally with the D70s. The way it works is the shutter opens fully, and then the sensor turns on for the amount of time necessary, let's say 1/1000th of a sec, then the second shutter closes. It's a very simple system, but what it means is, in effect, there is no max sync speed. The shutter is fully open at every shutter speed. This has made the D70s something of a cult favorite among strobists, but for some reason (probably to sell HSS flashes) Nikon stopped producing cameras with hybrid shutters. This is a niche Pentax could really take advantage of, since the D70s was only a 6MP camera, but first they need to re-enable at least the hotshoe or the PC socket above max sync speeds, the pop-up would be nice too for optical slaves."

I really hope that Pentax gives serious consideration to it in the K-3 and/or future cameras.

09-14-2012, 01:40 PM   #2
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QuoteOriginally posted by jake14mw Quote
I know many of you donít like to hear those of us that complain about the slow 1/180 max synch speed of Pentax. Whenever it comes up, many say it shouldnít matter, and some say, use High Speed Synch.

For me, it's a limitation in my senior portrait photography, and my sports photography. It puts me at a disadvantage because I use Pentax. Rather than me trying to explain it poorly, I'll point to a few examples of people who can explain it better than me.

in the news today: Strobist: Nikon D600: Think Twice Before You Jump In this one, David Hobby is actually saying that the fact that the new D600 has a flash synch speed of only 1/200 makes the camera a no-go for him.

A very good explanation of why itís important is here: Flash Sync Speed

Finally, one of our forum members, Maxfield Photo, gave a good explanation of why HSS is not the answer in most cases (from this thread https://www.pentaxforums.com/forums/general-photography-industry/198557-any-f...photokina.html)

"Basically max sync speed is the fastest speed at which the shutter is fully open at any one point in time. At speeds above the max sync the second curtain starts to close before the first curtain finishes opening, so what you get in effect is an ever-narrowing slit that moves across the sensor. HSS works by pulsing the flash at a reduced power for the entire time the shutters are in motion (1/180th of a sec in Pentax's case). The problem is the narrower the size of the moving slit, the more light is wasted bouncing off the curtains, and the less light that actually reaches the sensor. HSS can usually be used at normal flash distances up to about 1/1000th, but any faster than that and you'll have to get the flash very close to the subject, or use multiple speedlights as one lightsource (you may have seen the brackets for portable softboxes that acommodate up to four flashes) HSS is great for bringing some saturation back to your skies in outdoor portraits, but contrary to what the name might suggest, it's not good for capturing fast action.

To give you some idea, my Metz 58 has a normal max working distance of 20 meters at f/2.8, ISO 100, at it's maximum zoom setting of 105mm (that's with bare bulb, no modifiers). If I cross over into HSS territory, the working distance immediately drops to
4.8 meters @ 1/250th
4.3 meters @ 1/350th
3.4 meters @ 1/500th
3.0 meters @ 1/750th
and 2.4 meters @ 1/1000th

I could keep going, but you see the distances become really small, and that's without any light modifiers, who wants that? If Pentax would increase the max sync speed, not only would we not have to engage HSS as soon, but because the shutter curtains travel faster at 1/250th, the moving slit would actually be wider at any given shutter speed, allowing more light to reach the sensor, and less to be wasted by bouncing off the curtains - essentially making HSS more efficient.

Another way to solve this problem is to introduce a hybrid shutter. Nikon did this unintentionally with the D70s. The way it works is the shutter opens fully, and then the sensor turns on for the amount of time necessary, let's say 1/1000th of a sec, then the second shutter closes. It's a very simple system, but what it means is, in effect, there is no max sync speed. The shutter is fully open at every shutter speed. This has made the D70s something of a cult favorite among strobists, but for some reason (probably to sell HSS flashes) Nikon stopped producing cameras with hybrid shutters. This is a niche Pentax could really take advantage of, since the D70s was only a 6MP camera, but first they need to re-enable at least the hotshoe or the PC socket above max sync speeds, the pop-up would be nice too for optical slaves."

I really hope that Pentax gives serious consideration to it in the K-3 and/or future cameras.
I couldn't agree more.
09-14-2012, 01:51 PM   #3
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Pentax has a slow sync because of the SR most likely so it might mean no SR if you want 1/250 or different kind of shutter might do it.

What you say about the D70 can not be done with CMOS sensors, thats the reason we don't see it anymore.


As for the Metz 58 the flash discharge time at full power is 1/125 so you can't use 1/500 shutterspeed since half of the flash light won't be on it.

Last edited by Anvh; 09-14-2012 at 01:57 PM.
09-14-2012, 02:03 PM   #4
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while i don't disagree HSS is not the answer. I do have a few comments about misrepresentations made in the OP's post/

The issue with pentax and its sync speed is not the difference between 1/180 and 1/250, and if you want 1/250 just get a PZ-1, The bigger issue is that some vendors offer max sync speed at both leading edge and trailing edge sync, pentax does not, it cuts sync speed in half. this is nothing to do with the shutter, but more to do with the flash, which has a longer duration than other systems.

we need a better flash before we can get either higher sync or better trailing curtain sync. it is not only a camera limitation. the AF540FGz has a flash duration that is so long, even at 1/180th, you get darkening at one edge of the frame due to the flash still providing light while the trailing curtain is closing.

As for a higher sync speed changing the width of the moving slit, this is a guess on the OP as to the perceived increase in speed of the shutter blades, which may or may not happen. An improved flash may allow 1/250 with no change to the shutter, therefore if we get 1/250 by only an improved flash, nothing happens to the slit size.

but lets assume that the shutter can and does move faster, and we get a wider slit along with increased reach, is it an issue, what does the reach get you. I would rather have a more powerful, shorter duration flash, because I have seen that shots taken at partial power using my AF500FTZ (from my PZ-1) on my *istD gives sharper images than the AF540FGZ when used on the same camera with the same lenses, just because of the shorter duration at any light level.

every one take note, we are talking a system here. bitching about one component does not necessairly get what you need . pentax has always been weak in flash , the AF540FGZ is just an example of it

09-14-2012, 02:07 PM   #5
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QuoteOriginally posted by Anvh Quote
Pentax has a slow sync because of the SR most likely so it might mean no SR if you want 1/250 or different kind of shutter might do it.

What you say about the D70 can not be done with CMOS sensors, thats the reason we don't see it anymore.


As for the Metz 58 the flash discharge time at full power is 1/125 so you can't use 1/500 shutterspeed since half of the flash light won't be on it.
The Sony A99 has a flash sync of 1/250, and their own version of SR, so the "no SR" argument for Pentax doesn't fly.

Don't know about CMOS limitations. On that score you may be right.

How does the flash being on longer than the shutter is open mean that the sensor only gets half the light? I'm a bit confused on that one. Does that mean the Metz 58 doesn't work well on Canon or Nikon cameras with faster X-sync shutter speeds?

Just tryin' to learn this stuff.

Thanks
09-14-2012, 02:10 PM   #6
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Taking note...haven't really every understood most of this not sure I get it now either but...I am reading and learning.
09-14-2012, 02:14 PM   #7
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I believe the Olympus E-30 also has a max sych of 1/250 with in body shake reduction.
09-14-2012, 02:38 PM   #8
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QuoteOriginally posted by dgrosvold Quote
Does that mean the Metz 58 doesn't work well on Canon or Nikon cameras with faster X-sync shutter speeds?
No it means that if you choose to shoot faster than 1/125, you can't squeeze all the power out of the flash. Basically if you set the shutter speed to 1/250 on Canon and shoot the 58 in M mode on full power and then take another shot with same flash settings and shutter of 1/125, the latter will be brighter even though shutter isn't suppose to effect flash exposure. I bet Canon/Nikon flashes are similar (take longer than 1/250th to let out full power).

09-14-2012, 05:53 PM   #9
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I was wondering the same thing. Maybe it means it takes longer for the flash to attain full output?


QuoteOriginally posted by dgrosvold Quote
How does the flash being on longer than the shutter is open mean that the sensor only gets half the light? I'm a bit confused on that one. Does that mean the Metz 58 doesn't work well on Canon or Nikon cameras with faster X-sync shutter speeds?

Just tryin' to learn this stuff.

Thanks
09-14-2012, 07:08 PM   #10
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QuoteOriginally posted by Ponosby Britt Quote
What is it you cannot do because of the Pentax 1/180 max shutter speed?
except for shoot at 1/250, you have to try awful hard to find something,
09-14-2012, 07:44 PM   #11
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Did you guys read any of the links I put in?
09-14-2012, 07:45 PM   #12
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Metz is one of the few (perhaps the only) company that publishes their flash durations, but most if not all speedlights suffer from this same problem. When you vary the power of a speedlight, it doesn't actually change the brightness of the light being emitted, rather it changes the amount of time that the light stays on. Think of it as slices of time, we're talking about imperceptibly small amounts of time though.

With the Metz 58 AF2 at its lowest setting of 1/256th power for instance the light stays on for 1/33000th of a second, at full power it is on for 1/125th or 264/33000th of a second. But if you have your shutter speed set to 1/180th with the 58 AF2 on full power only 183 of those 264/33000th of a second are recorded with the shutter fully open, and then as Lowell says you get some darkening as the second curtain slides closed.

However, this is all a bit oversimplified because these lights also have a period of decay. It turns out that 1/125 is actually a measure of the T.1 duration of the Metz, or the point at which the light reaches 1/10th of it's initial brightness. According to Mattdm who called Metz customer support, the T.5 duration of the 58 AF2 is more like 1/1000th. So really while the second curtain is sliding closed you're only losing the tail end of the light. I tried it just now using my gray card as a target. It's barely noticeable, no more than a third of a stop. But with a 1/250th or 1/500th max sync, yes, it might be more noticeable. Now I don't know about you guys, but I prefer not to have my flash set to full power. By the time you cut the 58 back to half power the T.1 time becomes 1/650th and at quarter power the T.1 duration is 1/1500th so there's plenty of daylight killing power that can be gained from an increased sync speed.

Last edited by maxfield_photo; 09-15-2012 at 04:00 AM.
09-14-2012, 11:36 PM   #13
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QuoteOriginally posted by Ponosby Britt Quote
What is it you cannot do because of the Pentax 1/180 max shutter speed?
I wanna balance the ambient baby.

I want f2, 1/1000s Boo Yeah. i could use a tiny flash, and still get rid of any shadow, and still stop something quick.
09-15-2012, 06:21 AM   #14
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QuoteOriginally posted by dgrosvold Quote
The Sony A99 has a flash sync of 1/250, and their own version of SR, so the "no SR" argument for Pentax doesn't fly.

Don't know about CMOS limitations. On that score you may be right.

How does the flash being on longer than the shutter is open mean that the sensor only gets half the light? I'm a bit confused on that one. Does that mean the Metz 58 doesn't work well on Canon or Nikon cameras with faster X-sync shutter speeds?

Just tryin' to learn this stuff.

Thanks
Didn't knew that about the Sony, and it's also FF.

About the flash speed and the shutter speed.
basically how flash works is that the intensity of the light is roughly the same but they vari the duration to get more "flash light"
to explain very simply if a flash fires for 1 second, you get 2 times more light when it fires for 2 seconds.

With metz 58 the flash goes off for about 1/125 at full power that means that if your shutter speed is 1/250 that you cut away roughly half of the flash light to say it simply.
Since the shutter is already close while the flash is still giving off light.

Studio flashes work differently though, because they change the voltage of the capacitors to change the flash power the flash duration gets longer with lower power levels.
With hand flashes the duration gets shorter with the lower the flash power.
09-15-2012, 07:07 AM   #15
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QuoteOriginally posted by tromboads Quote
I want f2, 1/1000s Boo Yeah. i could use a tiny flash, and still get rid of any shadow, and still stop something quick.
I get 1/1000 w/ an Einstein at full power and a Panasonic LX5 at f/11 and cybersync or radiopopper triggers.
What you really want is an electronic shutter...if you want a DSLR, look at a Nikon D70 or D40.
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