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08-22-2011, 11:53 AM   #1
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Ricoh... Improve Pentax's Sync Speed! =)

Man! annoying 1/180sec sync speed! tsk tsk... Yeah, there's the High Speed Sync, but only available on Pentax flash, not available to all external flashes out there. And yeah, we can use an ND filter to stop down. But 1/180sec still isn't enough speed especially with subjects that are fast-moving. Some times, a lot of photographers want to shoot at f/2.8 or larger aperture then wanted to use a flash to lit those unwanted dark shadows and at the same time to eliminate motion blur. Other brands has a sync speed of 1/250sec., but still not enough. A 1/500sec. would be a great sync speed like the old Nikon D70s has. :ugh:
Anyway, I hope that Ricoh would improve the sync speed of Pentax cameras, if not, at least give more adjustment of the flash's power like from 1/1 down to 1/128 (for built-in flash)...

08-22-2011, 02:48 PM   #2
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QuoteOriginally posted by richard balonglong Quote
at least give more adjustment of the flash's power like from 1/1 down to 1/128 (for built-in flash)...
considering the NG of the K-x is around 12, K5 around 13, a simple 1/1 to 1/6 will be enought.

1/180 sync speed is not that much but enought most of time. A good balance between cost production and photo needs
08-22-2011, 03:03 PM   #3
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Well changing the sync-speed is a different matter then making a different oncamera flash. Did a poll on that, but not many demand for it (when it comes to costs) https://www.pentaxforums.com/forums/pentax-dslr-discussion/146228-k-3-speculation-new-flash.html

Maybe we will see some diffence in syncspeed. Currently the hole electronics are still the same as with the first dslr's or so. So maybe with new external flashes things would change with internal flash and electronic system supporting it.
08-22-2011, 03:07 PM - 1 Like   #4
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The fact is that with the high iso skills of current DSLR, there is almost no need for a more speedy flash.

And the only people who may need it, most of time, buy external flash.

On board flash is just a "just in case" flash, nothing more.

At least, that's how i see it.

08-22-2011, 03:13 PM   #5
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I don't understand the technical difficulty with this. OK so the flash fires, compensating for shutter lag, for >= 1/180th of a second. I saw someone post elsewhere that a faster shutter speed would fire before the flash did, but can that really be so hard to compensate? Surely they could make a 1/1000th second exposure fall within the 1/180th second flash?

I'd love to know what I'm missing here. I mean it shouldn't matter if the flash lasts longer than the exposure, should it?
08-22-2011, 03:50 PM   #6
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As I understand it the problem lies in that the type of shutter used in the Pentax does not open and close fully at high speed but rather moves a slit across the sensor.
If you don't compensate for this you end up with only part of your image exposed to the flash.
08-22-2011, 03:57 PM   #7
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QuoteOriginally posted by crewl1 Quote
As I understand it the problem lies in that the type of shutter used in the Pentax does not open and close fully at high speed but rather moves a slit across the sensor.
If you don't compensate for this you end up with only part of your image exposed to the flash.
My understanding as well.

It's not the speed of the entire shutter, but the velocity of its travel.

Remember the shutter shake issue? This may have something to do with it. Maybe a higher velocity shutter causes too much shake and that works against the SR. So a design decision was made to cap the flash sync to 1/180.

Might also be durability issues as well.
08-22-2011, 04:05 PM   #8
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Interesting, but it still doesn't really add up for me. It seems logical that regardless of how fast the shutter is, if the flash is illuminating for the entire exposure, it should be evenly exposed, if not as brightly overall. So again, fitting a 1/1000th second exposure (just as an example speed) into a 1/180th second "slot" should be easier.

Not trying to be argumentative Just wish I could wrap my head around it. Also wish I could afford a flash right now that could handle higher speeds, it's so annoying.

08-22-2011, 04:47 PM   #9
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QuoteOriginally posted by Philoslothical Quote
Interesting, but it still doesn't really add up for me. It seems logical that regardless of how fast the shutter is, if the flash is illuminating for the entire exposure, it should be evenly exposed, if not as brightly overall. So again, fitting a 1/1000th second exposure (just as an example speed) into a 1/180th second "slot" should be easier.

Not trying to be argumentative Just wish I could wrap my head around it. Also wish I could afford a flash right now that could handle higher speeds, it's so annoying.
1/180 is the fastest speed on a Pentax camera when 100% of the sensor area is exposed at a given point in the exposure. Any faster and the second curtain begins to cover the sensor before the first curtain is finished being fully open. In really fast shutter speed just a tiny slit between the curtains is open as the second curtain chases the first closely down the sensor. A flash is a very fast burst of light, and if only a tiny slit of the sensor is exposed then only a tiny portian of the sensor receives the flash illumination.
08-22-2011, 05:13 PM - 1 Like   #10
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QuoteOriginally posted by Philoslothical Quote
Just wish I could wrap my head around it. Also wish I could afford a flash right now that could handle higher speeds, it's so annoying.
Have a watch of this video. It'll take 10mins of your time, but should explain a few things:

With the Pentax shutter design, at any exposure faster than 1/180th, the entire sensor area is never fully exposed to the light at any one time; the 2nd shutter curtain is already moving.
08-22-2011, 05:50 PM   #11
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Brilliant, thanks! So my problem was that I was grossly overestimating the duration of the flash, during any length of exposure.

It's a wonder that they would need to strobe a high speed sync flash rather than just develop one that can illuminate longer at peak luminousity. I gather heat issues and filament longevity would both come into play, but it sounds like it would drastically simplify everything else.

Thanks for your patience on this.
08-22-2011, 08:20 PM   #12
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QuoteOriginally posted by richard balonglong Quote
great sync speed like the old Nikon D70s has. :ugh:
It used a hybrid shutter. Nikon doesn't even make that kind of SLR any more...that should tell you how viable that is

If you're freezing motion w/ sync speed, you don't understand strobes...
08-22-2011, 08:39 PM   #13
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QuoteOriginally posted by kenyee Quote
If you're freezing motion w/ sync speed, you don't understand strobes...
Not true at all.

Not all strobe photography is done in a dark room. When shooting action sports outside, you are typically mixing strobes with the constant ambient light. Let's say you're shooting BMX people do backflips, since this is a situation that's I've particularly had trouble with. It's the golden hour and sunset looks good. You want to drop down the ambient light a stop or two, so everything get nice and rich, but not so far that everything goes black. Then you want to add light back in on the BMXer. Problem is, they're moving really fast while they're doing that backflip, and since the constant, ambient light is still part of the exposure, the BMXer is going too fast for 1/180th.

What you end up with is almost a double frame, two seperate exposures. You get a nice sharp image of the BMXer from the flash, but you also have a blurry, ghosted image of the BMXer underneath the sharp one, and makes the whole BMXer look soft. The difference in motion blur from 1/180th to 1/250th is more than you would think, and it makes a big difference in these situations. The only thing you can do otherwise is stop down the ambient light so much that it's not a factor, which a) kills the ambience of the sunset and the golden hour scene, and b) requires huge amounts of watt/seconds.

Last edited by FullertonImages; 08-22-2011 at 09:20 PM.
08-22-2011, 08:54 PM   #14
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QuoteOriginally posted by aurele Quote
considering the NG of the K-x is around 12, K5 around 13, a simple 1/1 to 1/6 will be enought.
Yup, but sometimes (shooting under bright daylight) when you want a shallow DOF (f/2.8 or larger) with a shutter speed of at least 1/500sec but limited up to 1/180sec only and limited down to 1/6 of flash power only, the shot would end up overexposed and harsh flash on the subject's face. A power down to 1/128 with a higher sync speed would be a great combination. =)
08-22-2011, 08:58 PM   #15
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QuoteOriginally posted by FullertonImages Quote
Not true at all.

Not all strobe photography is done in a dark room. When shooting action sports outside, you are typically mixing strobes with the constant ambient light. Let's say you're shooting BMX people do backflips, since this is a situation that's I've particularly had trouble with. It's the golden hour and sunset looks good. You want to drop down the ambient light a stop or two, so everything get nice and rich, but not so far that everything goes black. Then you want to add light back in on the BMXer. Problem is, they're moving really fast while they're doing that backflip, and since the constant, ambient light is still part of the exposure, the BMXer is going too fast for 1/180th.

What you end up with and almost a double frame, two seperate exposures. YOu get a nice sharp image of the BMXer from the flash, but you also have a blurry, ghosted image of the BMXer underneath the sharp one, and it makes the whole images look soft. The difference in motion blur from 1/180th to 1/250th is more than you would think, and it makes a big difference in these situations. The only thing you can do otherwise is stop down the ambient light so much that it's not a factor, which a) kills the ambience of the sunset and the golden hour scene, and b) requires huge amounts of watt/seconds.
Well said friend! You saved me a lot of time explaining... =)
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