K-5 Sync limits.

Zebooka · 01-30-2011, 06:04 AM

Originally posted by Hound Tooth

But even a K-x has a built-in flash with variable output.

But if you are using full flash power, then you are in trouble. :ugh:

dlacouture · 01-30-2011, 07:07 AM

Now the problem would remain entire if you really want to balance ambient and flash, and freeze action... Only way here is a higher sync speed...

Then you'd maybe be better with a bridge camera, as they can sync as high as 1/4000 (well, my old Fuji S9500 can, anyway). That's the marvel of electronic shutter... I can't understand why DSLRs are not using this, by the way. Especially in Liveview...

**Digitalis** · 01-30-2011, 08:00 AM

Originally posted by dlacouture

I can't understand why DSLRs are not using this, by the way. Especially in Liveview

They are actually using electronic shutters in LV mode. However, they are using rolling shutters not global shutters like P&S cameras are using. There are still some major technical hurdles to overcome with implementing a global shutter in a large sensor the Nikon D70s is a good example of this.

From a technical standpoint a global shutter would superior to leaf shutters but with out any of their drawbacks(low top speed) and be able to synch at any speed providing the strobe is quick enough. With a camera armed with a global shutter my Elinchrom Studio heads (with the regular S tube) a synch speed of 1/2500 th should be feasible, though the radio triggering system could potentially get in the way of that.

dlacouture · 01-30-2011, 09:38 AM

Originally posted by Digitalis

They are actually using electronic shutters in LV mode. However, they are using rolling shutters not global shutters like P&S cameras are using. There are still some major technical hurdles to overcome with implementing a global shutter in a large sensor the Nikon D70s is a good example of this.

From a technical standpoint a global shutter would superior to leaf shutters but with out any of their drawbacks(low top speed) and be able to synch at any speed providing the strobe is quick enough. With a camera armed with a global shutter my Elinchrom Studio heads (with the regular S tube) a synch speed of 1/2500 th should be feasible, though the radio triggering system could potentially get in the way of that.

Optical slaves are the way to go, then... No perceptible delay with those...

As for the rolling shutter, I think it has more to do with the amount of data to handle each second...

For snatching just one pic, I'm pretty sure they could do it quite easily with the current sensors.

philbaum · 01-30-2011, 01:01 PM

Originally posted by dlacouture

Well, pentax inexplicably dropped the HSS wireless capabilities of their cameras when they went digital...
That's right : my 10 years old MZ-6 film body is able to do HSS in wireless mode, but my brand new K5 cannot...

I updated my Metz 48 to the latest firmware v1.1. I tried HSS in off camera mode with my K20, and it won't do it either. Not that i've ever needed to do HSS in off-camera mode :-)

It's almost like Pentax decided when they went into the digital age, which features to work on and which not to spend technical labor developing. HSS apparently was a less important feature at the time. Can't say i disagree :-)

Hound Tooth · 01-30-2011, 01:06 PM

Originally posted by dlacouture

Now the problem would remain entire if you really want to balance ambient and flash, and freeze action... Only way here is a higher sync speed...

Well... that, or more flashes to light up the rest of the scene.

Or in the immortal words of Roy Scheider in Jaws:

"We're gonna need a bigger flash"

JohanBene · 01-30-2011, 01:45 PM

Originally posted by Wheatfield

You are misunderstanding how focal plane shutters work.
Go back and read point 1 in the post you responded to.

Maybe you are misunderstanding me. To be clear I'm not talking about stopping motion.
If the second curtain covers part of the sensor it's still valuable to be able to flash the scene so that the other part of the frame (in wich you put your subject) gets flashexposed. Makes sense?

edit: If you have lots of wattseconds to fire away this wouldnt be much of an issue thoe

dlacouture · 01-30-2011, 03:30 PM

Originally posted by philbaum

It's almost like Pentax decided when they went into the digital age, which features to work on and which not to spend technical labor developing. HSS apparently was a less important feature at the time. Can't say i disagree :-)

It's worse than that, as it was already implemented and working in the MZ-6, MZ-S, *ist and *istD...

So they made a deliberate choice to remove it...

**Digitalis** · 01-30-2011, 04:25 PM

Originally posted by dlacouture

Optical slaves are the way to go, then... No perceptible delay with those...

But they are slower to use and have the range of a thrown elephant, Unless you are using a ringflash, or another external attached to the camera to set them off. No, radio triggers will be able to used for such high speeds they just have the eliminate transmitter latency further. As I said on my LX5 I can use my Elinchrom triggers reliably at 1/1300th, not shabby at all when you consider they are only designed for 1/250th and slower.

jake14mw · 01-31-2011, 01:33 PM

Originally posted by Wheatfield

Originally posted by jake14mw
The thing I don't understand is, why can't Pentax allow the flash signal to be sent when using higher shutter speeds than 1/180th? How hard is it to add an override to the menu to allow this, and allow us to deal with any black bands that occur? Call it "Override Safe Sych Limit?". It can't be expensive to add this.
First, it would make no difference, since the shutter is moving at a finite speed (1/180th). All you would be getting is an unexposed band, with exactly the same exposure time as you'd get at 1/180th second.
This can be a hard concept to get one's head around, and most people seem to misunderstand it.
Second, they could add the moon to the camera, and all that would happen is there would be more things to go wrong, people would still complain, and they would also be complaining about the extra cost.

Help me with this. I don't understand your statement saying that the shutter is moving at a finite speed of 1/180th of a second? I'm talking about allowing an external flash to fire in manual mode when the shutter speed is 1/250th of a second. My understanding is that I would get a black band at the bottom of the frame in that case. I'm saying let me deal with that in PP, so that I can use 1/250th of a second. If I'm missing something here, I'd like to know about it. Thanks.

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01-30-2011, 06:04 AM	#76
Zebooka Veteran Member Join Date: May 2008 Location: Russia, Siberia, Novosibirsk Posts: 323	Originally posted by Hound Tooth But even a K-x has a built-in flash with variable output. But if you are using full flash power, then you are in trouble. :ugh:

01-30-2011, 07:07 AM	#77
dlacouture Veteran Member Join Date: Jul 2008 Location: Var, South of France Photos: Albums Posts: 1,074	Now the problem would remain entire if you really want to balance ambient and flash, and freeze action... Only way here is a higher sync speed... Then you'd maybe be better with a bridge camera, as they can sync as high as 1/4000 (well, my old Fuji S9500 can, anyway). That's the marvel of electronic shutter... I can't understand why DSLRs are not using this, by the way. Especially in Liveview...

01-30-2011, 08:00 AM	#78
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Originally posted by dlacouture I can't understand why DSLRs are not using this, by the way. Especially in Liveview They are actually using electronic shutters in LV mode. However, they are using rolling shutters not global shutters like P&S cameras are using. There are still some major technical hurdles to overcome with implementing a global shutter in a large sensor the Nikon D70s is a good example of this. From a technical standpoint a global shutter would superior to leaf shutters but with out any of their drawbacks(low top speed) and be able to synch at any speed providing the strobe is quick enough. With a camera armed with a global shutter my Elinchrom Studio heads (with the regular S tube) a synch speed of 1/2500 th should be feasible, though the radio triggering system could potentially get in the way of that.

01-30-2011, 09:38 AM	#79
dlacouture Veteran Member Join Date: Jul 2008 Location: Var, South of France Photos: Albums Posts: 1,074	Originally posted by Digitalis They are actually using electronic shutters in LV mode. However, they are using rolling shutters not global shutters like P&S cameras are using. There are still some major technical hurdles to overcome with implementing a global shutter in a large sensor the Nikon D70s is a good example of this. From a technical standpoint a global shutter would superior to leaf shutters but with out any of their drawbacks(low top speed) and be able to synch at any speed providing the strobe is quick enough. With a camera armed with a global shutter my Elinchrom Studio heads (with the regular S tube) a synch speed of 1/2500 th should be feasible, though the radio triggering system could potentially get in the way of that. Optical slaves are the way to go, then... No perceptible delay with those... As for the rolling shutter, I think it has more to do with the amount of data to handle each second... For snatching just one pic, I'm pretty sure they could do it quite easily with the current sensors.

01-30-2011, 01:01 PM	#80
philbaum Veteran Member Join Date: Oct 2007 Location: Port Townsend, Washington State, USA Posts: 3,659	Originally posted by dlacouture Well, pentax inexplicably dropped the HSS wireless capabilities of their cameras when they went digital... That's right : my 10 years old MZ-6 film body is able to do HSS in wireless mode, but my brand new K5 cannot... I updated my Metz 48 to the latest firmware v1.1. I tried HSS in off camera mode with my K20, and it won't do it either. Not that i've ever needed to do HSS in off-camera mode :-) It's almost like Pentax decided when they went into the digital age, which features to work on and which not to spend technical labor developing. HSS apparently was a less important feature at the time. Can't say i disagree :-)

01-30-2011, 01:06 PM	#81
Hound Tooth Banned Join Date: Nov 2010 Location: Williston, VT Posts: 268	Originally posted by dlacouture Now the problem would remain entire if you really want to balance ambient and flash, and freeze action... Only way here is a higher sync speed... Well... that, or more flashes to light up the rest of the scene. Or in the immortal words of Roy Scheider in Jaws: "We're gonna need a bigger flash"

01-30-2011, 01:45 PM	#82
JohanBene New Member Join Date: Apr 2009 Location: Stockholm Posts: 11	Originally posted by Wheatfield You are misunderstanding how focal plane shutters work. Go back and read point 1 in the post you responded to. Maybe you are misunderstanding me. To be clear I'm not talking about stopping motion. If the second curtain covers part of the sensor it's still valuable to be able to flash the scene so that the other part of the frame (in wich you put your subject) gets flashexposed. Makes sense? edit: If you have lots of wattseconds to fire away this wouldnt be much of an issue thoe

01-30-2011, 03:30 PM	#83
dlacouture Veteran Member Join Date: Jul 2008 Location: Var, South of France Photos: Albums Posts: 1,074	Originally posted by philbaum It's almost like Pentax decided when they went into the digital age, which features to work on and which not to spend technical labor developing. HSS apparently was a less important feature at the time. Can't say i disagree :-) It's worse than that, as it was already implemented and working in the MZ-6, MZ-S, ist and istD... So they made a deliberate choice to remove it...

01-30-2011, 04:25 PM	#84
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Originally posted by dlacouture Optical slaves are the way to go, then... No perceptible delay with those... But they are slower to use and have the range of a thrown elephant, Unless you are using a ringflash, or another external attached to the camera to set them off. No, radio triggers will be able to used for such high speeds they just have the eliminate transmitter latency further. As I said on my LX5 I can use my Elinchrom triggers reliably at 1/1300th, not shabby at all when you consider they are only designed for 1/250th and slower.

01-31-2011, 01:33 PM	#85
jake14mw Veteran Member Join Date: Jan 2008 Location: Connecticut, USA Posts: 977	Originally posted by Wheatfield Originally posted by jake14mw The thing I don't understand is, why can't Pentax allow the flash signal to be sent when using higher shutter speeds than 1/180th? How hard is it to add an override to the menu to allow this, and allow us to deal with any black bands that occur? Call it "Override Safe Sych Limit?". It can't be expensive to add this. First, it would make no difference, since the shutter is moving at a finite speed (1/180th). All you would be getting is an unexposed band, with exactly the same exposure time as you'd get at 1/180th second. This can be a hard concept to get one's head around, and most people seem to misunderstand it. Second, they could add the moon to the camera, and all that would happen is there would be more things to go wrong, people would still complain, and they would also be complaining about the extra cost. Help me with this. I don't understand your statement saying that the shutter is moving at a finite speed of 1/180th of a second? I'm talking about allowing an external flash to fire in manual mode when the shutter speed is 1/250th of a second. My understanding is that I would get a black band at the bottom of the frame in that case. I'm saying let me deal with that in PP, so that I can use 1/250th of a second. If I'm missing something here, I'd like to know about it. Thanks.