The shutter lag of the Z7

[michaeladawson]

you are Right in case of flash photography, where the first curtain Needs to fully expose the sensor.

It depends on the flash situation that you're facing, obviously. Fill flash vs. a truly dim scene. The exposure always starts as soon as the first shutter starts opening. But you know that.

I'm OK with the method being used to measure the shutter lag. As long as we know the method we can compare between cameras. And it looks like Olyflyer got numbers similar to the testers in Jim Kasson's link.

 

[olyflyer]

* no matter what you interprete int he measuring results, it is known, that my finger and eye are not fast enough to notice the difference between mech Speed and electronic Speed of first curtain.

Well, you must be pretty slow, because the difference can be a portraits with eyes shut or open... of course, one can always machine gun the model and hope for the best... The difference between the electronic shutter and the mechanical is very large, but you are right, I have to take a few more pics similarly as I tested the electronic shutter but with the EFCS and mechanical shutter so that I get some reference results, after all, the mechanical and the EFCS is accurately measured.

you are Right in case of flash photography, where the first curtain Needs to fully expose the sensor.

Not necessary in all the cases. High speed flash photography is an example.

in case of 1/8000s exposure time I do doubt that there is so much difference in lag between trigger and actual exposure of the sensor (mech shutter versus electronic first curtain)

The difference is just 6ms, and this is understandable since the sensor needs to close the mechanical shutter first, before it can start opening the first curtain. My guess is that this 6ms difference is what it takes to close the shutter.

I will test the fully electronic shutter once again and as I said, I will test the mechanical and EFCS the same way to have a reference. Based on the images I can calculate a more exact value for the fully electronic shutter as well. I hope I was totally wrong and the fully electronic shutter is similar to the other two, or even better, but I don't think so, even if there will be some differences, it will be marginal from the 108ms I measured initially.

BTW, EFCS works only up to 1/2000s, so it is not possible to compare them at 1/8000s.

 

[Horshack]

anyhow:

* your measurements prove, that the travel Speed of electronic shutter is slower than the travel Speed of mech shutter, what was expected.

Yes and no... and in this part I know I am not 100% accurate, since I take an image and that image need to be recorded, so the 108ms is actually shorter to the first curtain being fully open time. The time is 108ms - 2.5ms = 105.5ms isn't it?

This is still pretty far from the mechanical shutter and that is normal. The electronic shutter is slower than the mechanical, considerably slower.

Since your technique for the electronic shutter (ES) involves taking a photo, that measurement will include the sensor readout time (at least up to the sensor rows where your LCD display is positioned in the frame), whereas your mechanical/ES technique do not. That readout time must then be subtracted from your calculation otherwise the ES lag measurement will appear slower than it actually is.

 

[mcabato]

now i wondered, what's the difference between you rmeasurement and that of Jim:

I am not quite sure, because english cultured People use so much abbreviations which are not known by me.

but I do understand, that you measure the time betweend trigger and first curtain fully open, while Jim I am not sure, whether Jim starts the actual measuring by Signal of the remote Control or wheter he only activates cam and oscilloscope by the remote Control signal.

Jim is clear that he uses the x-contact of the cam to determine the first curtain to be fully open (x-contact closure).

so, I do assume that the difference in time results between yours and Jims for actuation and travel of electronic first curtain (yours are in line with that of Imaging resources measurements) must have to do with start Signal of measurement, although Jim is mentioning something about time for "winding the mechanical shutter")

so, in my understanding, without considering processes for AF, the shutter Action for one exposure contains the following times:

1) delay between trigger and close command to the shutter

2) closing time of shutter

3) delay between shutter having fully closed and start of travel of first curtain

4) travel time of first curtain

5) exposure-time-dependent delay between start of travel of first curtain and start of travel of second curtain

6) travel time of 2nd curtain.

so, olyflier, I do assume you measured the sum of times of 1) to 4),

whereas Jim measured what?

Question: item 2) above: is there any difference for EFCs and mech shutter - why not Always Closing the shutter (= resetting the sensor before exposure) by electronic curtains? Is it a cause for the difference between Jims and your measurements?

BR gusti

 

[mcabato]

I hope I was totally wrong and the fully electronic shutter is similar to the other two, or even better, but I don't think so, even if there will be some differences, it will be marginal from the 108ms I measured initially.

BTW, EFCS works only up to 1/2000s, so it is not possible to compare them at 1/8000s.

that the travel time of fully electronic shutter is quite Long compared to travel time of electronic first curtain or mechanical first curtain is clear and well known - due to the line by line readout process for fully electronic shutter (see also Horshacks post below)

my initial issue was: we had a different understanding what the Expression "shutter lag" means. I did understand the command time and you the command time plus travel time.

now my issue is: why Jim measures 24ms for EFCS and you and also Imaging resource measure 60ms, while the times all of you measure for mechanical shutter are more or less the same.

BR gusti

 

[JimKasson]

As far as I know, the shutter lag of the Nikon Z 7 is not officially documented by Nikon, unlike the other professional grade DSLRs, so I decided to measure it with my measuring devices. I have previously measured all my cameras, so of course, I wanted to measure even the Nikon Z 7.

Definition of shutter lag: The delay it takes for the camera to open the shutter from the time the shutter release button is pressed. The camera is in manual focus and manual exposure mode so that no delay is added due to other activities the camera might need time for. The camera is triggered with wired connection from my devices to eliminate the delay caused by the triggering device.

Results:

Fully electronic shutter: 108ms shutter lag



Currently the electronic shutter can only be tested with my first version of Shutter lag tester, but the tests are reliable, accurate and repeatable.

Fully mechanical shutter: 69ms shutter lag



The new shutter lag tester is not ready yet, but it works just fine for this and it has been properly tested so I know it is showing the right measurements.

Electronic first curtain shutter: 63ms shutter lag



All measurements are based on average calculations of 10 images. the differences between each measurements are very small. My new device does the average calculations automatically and also triggers the camera repeatedly until all the shutter actuations are made, after that the result is displayed.

Conclusions:

The Z7 is slower than the previous Nikon D800 I had. The D300s has a shutter lag of 52ms in 12-bit mode and 95ms in 14-bit mode. The D800 has a shutter lag of 44ms in both 12-bit and 14-bit modes. The Z 7 is slower than the D800 but faster than the D300s in 14-bit mode. The shutter lag of the Z 7 is not dependent on 12/14 mode, or JPEG/NEF output, the shutter lag is constant, depending only on the type of shutter used.

I even made a video, so if you want to watch how I measure this you can visit my YouTube video.

This is nce work. Can you share the details of your test protocol?

The principal is that the camera is triggered, like if you'd slam the shutter release button without half pressing first. This activates the camera and starts a timer.

The timer is stopped on trigger signal from the flash X-sync contact, which indicates the end of the first curtain movement and the start of the second, the shutter closure.

So you are doing the same measurement that I am, with two differences.

1. I start mine with the shutter half-pressed (electronically, of course)
2. I measure the time with a 'scope.

The time is measured by a dedicated hardware, the first version (black box) is based in a Microchip PIC microcontroller, the hardware and the firmware was developed by me. It is entirely written in Microchip assembler and each routine is precisely timed and measured for accuracy. I have many years of real time, and time critical applications firmware programming experience, so it was a fairly simple task, though it did take some time to make it.

The second is on an Arduino based unit, smaller and hardware wise simpler because most of the hardware is readily available. This time the firmware is written in C and C++, allowing higher complexity and a lot of extra features, like logging to PC, automatic repeatability tests, average calculations, IR triggering of many brands, sound triggering of the measurements and so on. IR and sound is useful for cameras without wire trigger or flash X-sync outputs. Of course, the shutter lag measured that way is less accurate, but it is still OK in those cases. In both versions I am using precisely timed firmware based on interrupt handling of the signals.

What I can't do with my new device (for now) is to measure the shutter lag of the electronic shutter because there is no flash X-sync output in that case, so I need to use my initial, first version of shutter lag tester for that. This is an issue I have to solve before I can call my version two ready.

I have freely offered all the details of the first version, including the firmware, from the start, but later I decided to remove the offer for personal reasons, and because I wanted to sell it and get some of my efforts financed by it. A batch of the first version was sold as a test product to several camera repair centres and testers around the globe, and so far nobody complained about the accuracy or the method of my device. I stopped making the first version because it was too complicated and expensive for me to make it since it is a low volume product. The second version will be available soon, but these activities are hobby activities for me, so it isn't always the highest priority since my daily bread and milk is not dependent on them.

Anyway, I can't give more details right now.

That's plenty for me to see what you're doing.

I've never seen such a low difference between EFCS and all-mechanical shutter lag on a MILC.

Here's my setup:

https://blog.kasson.com/a7iii/sony-a7iii-shutter-latency/

https://blog.kasson.com/a7iii/sony-a7iii-shutter-latency-efcs/

Nice work. The only thing I wonder is how you can get the same time with AF-S as with MF. Auto focus takes some time, and the speed of that is dependent on many parameters (len, light, focus distance, target, focus mode...), and is not consistent enough, which is why I don't care about it and not include in the shutter lag.

I start my measurements with the shutter half-pressed.

Of course, my devices can be used to measure AF speed also, but that's a different thing. Anyway, how come that you arrived to these values, which consistently show the same for MF and AF-S, as well as the no lens situation?

I start my measurements with the shutter half-pressed.

I also find the 22ms and 24ms EXTREMELY fast. But it is possible that the Sony is faster than any other camera, I don't know. Have you verified your measurements against a known value, like the D800, which is even documented by Nikon?

I no longer have a D800. I measure the D5 at 45 ms, if I remember right.

By the way, I have to repeat my measurements even without a lens. I don't know if it makes a difference, I don't think so, but never the less, it must be tested.

--
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the last word the last word - Photography meets digital computer technology. Photography wins -- most of the time.

Photography meets digital computer technology. Photography wins -- most of the time.

blog.kasson.com

 

[JimKasson]

How does your measuring device know when the shutter starts to open?

That is not really relevant. My device knows when the first curtain is fully open, this is when the image is taken. When the first shutter starts to open, the camera is still not ready.

Actually, both your and my techniques don't know when the shutter is fully open, but only when the camera says it is. That's plenty good enough for this exercise, though.

However, at high shutter speeds, that moment in time marks the end of the exposure, not its beginning.

 

[JimKasson]

How does your measuring device know when the shutter starts to open?

That is not really relevant. My device knows when the first curtain is fully open, this is when the image is taken. When the first shutter starts to open, the camera is still not ready.

For us to understand and believe the data, we'd like to know how it works. This is kind of like you publishing a scientific paper full of data and not describing how the data was obtained. Credibility comes from understanding how it was measured. I'm not sure why you're objecting to explaining it or how you can possibly say it's not relevant.

Well explained up above...

 

[JimKasson]

* no matter what you interprete int he measuring results, it is known, that my finger and eye are not fast enough to notice the difference between mech Speed and electronic Speed of first curtain.

Well, you must be pretty slow, because the difference can be a portraits with eyes shut or open... of course, one can always machine gun the model and hope for the best... The difference between the electronic shutter and the mechanical is very large, but you are right, I have to take a few more pics similarly as I tested the electronic shutter but with the EFCS and mechanical shutter so that I get some reference results, after all, the mechanical and the EFCS is accurately measured.

you are Right in case of flash photography, where the first curtain Needs to fully expose the sensor.

Not necessary in all the cases. High speed flash photography is an example.

in case of 1/8000s exposure time I do doubt that there is so much difference in lag between trigger and actual exposure of the sensor (mech shutter versus electronic first curtain)

The difference is just 6ms, and this is understandable since the sensor needs to close the mechanical shutter first, before it can start opening the first curtain. My guess is that this 6ms difference is what it takes to close the shutter.

Travel time for the mechanical shutter is about 4 msec. If it were 6 msec, it couldn't offer 1/200 sec X-Synch.

Travel time for the electronic shutter is about 60 msec.

 

[JimKasson]

now i wondered, what's the difference between you rmeasurement and that of Jim:

1. I start mine with the shutter half-pressed (electronically)
2. I measure the time with a 'scope.

The first difference will make the measure delay smaller, and, I believe, replicates the more common situation where the photographer is holding the shutter release halfway down to hold focus while waiting for something to happen.

The second means that my measurements with not be as precise for long latencies (about 1 part in 100 measurement error in my case, about +/- 1 LSD in the OP's, before averaging.).

Oh, sorry. LSD doesn't stand for a hallucigen, here, but for least significant digit.

Jim

 

[mcabato]

...about +/- 1 LSD...

Oh, sorry. LSD doesn't stand for a hallucigen, here, but for least significant digit.

Jim

thanks!

gusti

 

[olyflyer]

How does your measuring device know when the shutter starts to open?

That is not really relevant. My device knows when the first curtain is fully open, this is when the image is taken. When the first shutter starts to open, the camera is still not ready.

Actually, both your and my techniques don't know when the shutter is fully open, but only when the camera says it is. That's plenty good enough for this exercise, though.

However, at high shutter speeds, that moment in time marks the end of the exposure, not its beginning.

By fully open in this concept I mean as open as it is going to be, not at the end of movement.

The shutter is never fully open after the sync speed.

 

[mcabato]

now i wondered, what's the difference between you rmeasurement and that of Jim:

1. I start mine with the shutter half-pressed (electronically)
   ...

The first difference will make the measure delay smaller, and, I believe, replicates the more common situation where the photographer is holding the shutter release halfway down to hold focus while waiting for something to happen.

...

Jim

any idea which technical processes cause the difference in resulting lag between

1) fully Pressing the button at once without "half Pressing it" in between, using the EFC mode

and

2) fully pressing down the half pressed button, using the EFC mode

* I do assume the shutter being wide open until in both cases the button is fully pressed.

* So, the "start to take exposure" command can only be given after the release button had been fully pressed for both cases 1) and 2).

one difference between 1) and 2) is probabliy the process of light metering, which in 1) did not accur before 1) started …but this should take the same time for mech shutter and also for EFC?

for sure there are Logical checking routines (which Buttons are pressed, which af mode is selected (and how far af process has progressed, if not deactivated as beinig the case in our example) going on between release button Pressing and sending the command to the shutter curtains. …but this should take the same time for mech shutter and also for EFC?

* in both 1) and 2) the shutter must be closed and in both cases the shutter Closing should take the same time …

1) and 2) seem to give same results for mech shutter, but not for EFC mode. why?

BR gusti

 

[JimKasson]

now i wondered, what's the difference between you rmeasurement and that of Jim:

1. I start mine with the shutter half-pressed (electronically)
   ...

The first difference will make the measure delay smaller, and, I believe, replicates the more common situation where the photographer is holding the shutter release halfway down to hold focus while waiting for something to happen.

...

Jim

any idea which technical processes cause the difference in resulting lag between

1) fully Pressing the button at once without "half Pressing it" in between, using the EFC mode

and

2) fully pressing down the half pressed button, using the EFC mode

In AF, the camera will have focused if you have done a half-press, where it will have to focus if you have not.

* I do assume the shutter being wide open until in both cases the button is fully pressed.

* So, the "start to take exposure" command can only be given after the release button had been fully pressed for both cases 1) and 2).

Yes.

one difference between 1) and 2) is probabliy the process of light metering, which in 1) did not accur before 1) started …but this should take the same time for mech shutter and also for EFC?

Metering is being done continuously and is reported in the finder.

for sure there are Logical checking routines (which Buttons are pressed, which af mode is selected (and how far af process has progressed, if not deactivated as beinig the case in our example) going on between release button Pressing and sending the command to the shutter curtains. …but this should take the same time for mech shutter and also for EFC?

* in both 1) and 2) the shutter must be closed and in both cases the shutter Closing should take the same time …
1) and 2) seem to give same results for mech shutter, but not for EFC mode. why?
BR gusti

The half-press versus none does not explain an EFCS vs mechanical shutter difference, should one exist.

I have not measured the Z7 myself yet, though. It may be that the camera is operating the shutter differently than I've seen before with other MILCs.

Jim

 

[mcabato]

By fully open in this concept I mean as open as it is going to be, not at the end of movement.

The shutter is never fully open after the sync speed.

but you are using the x-contact for all measurements ... does this x-contact close at "higher" (you name it "after") shutter Speeds earlier than the first curtain having accomplised full travel?

br gusti

 

[JimKasson]

By fully open in this concept I mean as open as it is going to be, not at the end of movement.

The shutter is never fully open after the sync speed.

but you are using the x-contact for all measurements ... does this x-contact close at "higher" (you name it "after") shutter Speeds earlier than the first curtain having accomplised full travel?

br gusti

With mechanical and EFCS, it's pretty easy to correct results if the start of exposure is the desired metric. In the Z7, just subtract 4 msec from the OP's reported result.

Jim

 

[olyflyer]

As far as I know, the shutter lag of the Nikon Z 7 is not officially documented by Nikon, unlike the other professional grade DSLRs, so I decided to measure it with my measuring devices. I have previously measured all my cameras, so of course, I wanted to measure even the Nikon Z 7.

Definition of shutter lag: The delay it takes for the camera to open the shutter from the time the shutter release button is pressed. The camera is in manual focus and manual exposure mode so that no delay is added due to other activities the camera might need time for. The camera is triggered with wired connection from my devices to eliminate the delay caused by the triggering device.

Results:

Fully electronic shutter: 108ms shutter lag



Currently the electronic shutter can only be tested with my first version of Shutter lag tester, but the tests are reliable, accurate and repeatable.

Fully mechanical shutter: 69ms shutter lag



The new shutter lag tester is not ready yet, but it works just fine for this and it has been properly tested so I know it is showing the right measurements.

Electronic first curtain shutter: 63ms shutter lag



All measurements are based on average calculations of 10 images. the differences between each measurements are very small. My new device does the average calculations automatically and also triggers the camera repeatedly until all the shutter actuations are made, after that the result is displayed.

Conclusions:

The Z7 is slower than the previous Nikon D800 I had. The D300s has a shutter lag of 52ms in 12-bit mode and 95ms in 14-bit mode. The D800 has a shutter lag of 44ms in both 12-bit and 14-bit modes. The Z 7 is slower than the D800 but faster than the D300s in 14-bit mode. The shutter lag of the Z 7 is not dependent on 12/14 mode, or JPEG/NEF output, the shutter lag is constant, depending only on the type of shutter used.

I even made a video, so if you want to watch how I measure this you can visit my YouTube video.

This is nce work. Can you share the details of your test protocol?

The principal is that the camera is triggered, like if you'd slam the shutter release button without half pressing first. This activates the camera and starts a timer.

The timer is stopped on trigger signal from the flash X-sync contact, which indicates the end of the first curtain movement and the start of the second, the shutter closure.

So you are doing the same measurement that I am, with two differences.

Yes, basically we are doing the same thing, but using different means to measure.

1. I start mine with the shutter half-pressed (electronically, of course)

Half press is simulated by my devices because that is necessary for the camera, otherwise it will not trigger at all. However, the function of half press (AF and metering) is not relevant in my case here, since I have the camera set to manual. My device can also measure AF speed and in that case the half press is more important.

2. I measure the time with a 'scope.

If I had not made my own dedicated instruments for the tasks of camera testing, I could use a scope as well, but I prefer it this way. I have many instruments, even a very accurate timer/counter/signal generator. If I did not have two dedicated, completely independent devices to measure, I would have used my signal generator/counter to verify my measurements.

The time is measured by a dedicated hardware, the first version (black box) is based in a Microchip PIC microcontroller, the hardware and the firmware was developed by me. It is entirely written in Microchip assembler and each routine is precisely timed and measured for accuracy. I have many years of real time, and time critical applications firmware programming experience, so it was a fairly simple task, though it did take some time to make it.

The second is on an Arduino based unit, smaller and hardware wise simpler because most of the hardware is readily available. This time the firmware is written in C and C++, allowing higher complexity and a lot of extra features, like logging to PC, automatic repeatability tests, average calculations, IR triggering of many brands, sound triggering of the measurements and so on. IR and sound is useful for cameras without wire trigger or flash X-sync outputs. Of course, the shutter lag measured that way is less accurate, but it is still OK in those cases. In both versions I am using precisely timed firmware based on interrupt handling of the signals.

What I can't do with my new device (for now) is to measure the shutter lag of the electronic shutter because there is no flash X-sync output in that case, so I need to use my initial, first version of shutter lag tester for that. This is an issue I have to solve before I can call my version two ready.

I have freely offered all the details of the first version, including the firmware, from the start, but later I decided to remove the offer for personal reasons, and because I wanted to sell it and get some of my efforts financed by it. A batch of the first version was sold as a test product to several camera repair centres and testers around the globe, and so far nobody complained about the accuracy or the method of my device. I stopped making the first version because it was too complicated and expensive for me to make it since it is a low volume product. The second version will be available soon, but these activities are hobby activities for me, so it isn't always the highest priority since my daily bread and milk is not dependent on them.

Anyway, I can't give more details right now.

That's plenty for me to see what you're doing.

I've never seen such a low difference between EFCS and all-mechanical shutter lag on a MILC.

Here's my setup:

Sony a7III shutter latency - the last word

Sony a7III, a7RIII, a9 shutter latency — EFCS - the last word

Nice work. The only thing I wonder is how you can get the same time with AF-S as with MF. Auto focus takes some time, and the speed of that is dependent on many parameters (len, light, focus distance, target, focus mode...), and is not consistent enough, which is why I don't care about it and not include in the shutter lag.

I start my measurements with the shutter half-pressed.

I have a 300ms delay between the "half press" and the actual shutter release signal, but the time measurement is not not taking this into account and starts only after the "shutter release" signal. You can actually visually see this 300ms in my video, the white LED is turned on 300ms before the red, the red is actually the shutter release. Note, before anyone mentions the long time those LEDs are lit: none of that is part of the measurements, the LEDs are handled outside and they are just for visual indication of the signals.

Of course, my devices can be used to measure AF speed also, but that's a different thing. Anyway, how come that you arrived to these values, which consistently show the same for MF and AF-S, as well as the no lens situation?

I start my measurements with the shutter half-pressed.

I also find the 22ms and 24ms EXTREMELY fast. But it is possible that the Sony is faster than any other camera, I don't know. Have you verified your measurements against a known value, like the D800, which is even documented by Nikon?

I no longer have a D800. I measure the D5 at 45 ms, if I remember right.

I never had the D5 so I don't know, but you see, the 22ms is EXTREMELY short time, and I'd actually expect the D5 to be faster than the Sony you have in the table below.

By the way, I have to repeat my measurements even without a lens. I don't know if it makes a difference, I don't think so, but never the less, it must be tested.

I have now repeated the tests, and it makes no difference if I have a lens on or not. My measurements show the same values, so I guess this ends my shutter lag testing, and the next time it will be for final test of my second instrument.

 

[olyflyer]

By fully open in this concept I mean as open as it is going to be, not at the end of movement.

The shutter is never fully open after the sync speed.

but you are using the x-contact for all measurements ... does this x-contact close at "higher" (you name it "after") shutter Speeds earlier than the first curtain having accomplised full travel?

br gusti

There is a flash signal even at higher shutter speeds, but unless you switch to high speed flash use, the image will be vignetted if you try to use a flash above the sync speed.

Here are four pictures demonstrating what I mean.



This is taken at the sync speed, 1/200s and I had an old manual flash on the camera.



The next is taken at 1/250s, no vignetting with this flash because it can actually handle up to 1/320s normally.



This is what happens when you go faster, this one is taken at 1/500s, and here the vignetting shows but the flash is fired, so there is a flash signal (X-contact close as you call it).



As the shutter speed increase, the slit of the shutter gets narrower.

This continues until 1/8000s with the mechanical shutter and 1/2000s with the electronic first curtain. The fully electronic shutter does not give the X-signal, which is why I had to take an image of my timer automatically with the camera.

I think there is a misunderstanding regarding when "the first curtain having accomplished full travel". The full travel is done of course only when the shutter reached the other end, but that is not interesting here. I want to trigger the timer, when the first curtain is at the maximum opening, be that the end of the travel (like at 1/200s or shorter shutter speeds) or, like in the above examples, wherever the shutter is completed the MAXIMUM opening it has to complete for the shutter speed, and that is indicated by the X-sync signal.

I guess that's what you mean by your question, but ask again if I misunderstood you.

 

[mcabato]

By fully open in this concept I mean as open as it is going to be, not at the end of movement.

The shutter is never fully open after the sync speed.

but you are using the x-contact for all measurements ... does this x-contact close at "higher" (you name it "after") shutter Speeds earlier than the first curtain having accomplised full travel?

br gusti

There is a flash signal even at higher shutter speeds, but unless you switch to high speed flash use, the image will be vignetted if you try to use a flash above the sync speed.

Here are four pictures demonstrating what I mean.



This is taken at the sync speed, 1/200s and I had an old manual flash on the camera.



The next is taken at 1/250s, no vignetting with this flash because it can actually handle up to 1/320s normally.



This is what happens when you go faster, this one is taken at 1/500s, and here the vignetting shows but the flash is fired, so there is a flash signal (X-contact close as you call it).



As the shutter speed increase, the slit of the shutter gets narrower.

This continues until 1/8000s with the mechanical shutter and 1/2000s with the electronic first curtain. The fully electronic shutter does not give the X-signal, which is why I had to take an image of my timer automatically with the camera.

I guess that's what you mean by your question, but ask again if I misunderstood you.

no, thanks, this is what I meant and Jim had it already adressed.

thank you both!

my take away from this thread is:

1) Jims measurements on sony, results correlating to those of Imaging resource

Show differernt lag time for mech shutter and EFCs (roughly 90ms vs 24ms).

2) your measurements on Nikon z, results correlating to those of Imaging resource

Show nearly same lag time for mech shutter and EFCs (roughly 60ms vs 60ms).

3) travel time of mech curtain and also for EFC is 4ms for modern cams with short sync Speed

4) big part of shutter lag seems to come from closure of shutter and resetting the sensor before start of exposure.

considering the short time shutters Need to move as per 3) , there seems to be a different way of resetting sensor/emptying Pixel charge between sony and Nikon z, I do guess based on the remarkable differenc in EFCS lag between sony and Nikon.

thanks for the interesting Details and discussion!

br gusti

 

[JimKasson]

By fully open in this concept I mean as open as it is going to be, not at the end of movement.

The shutter is never fully open after the sync speed.

but you are using the x-contact for all measurements ... does this x-contact close at "higher" (you name it "after") shutter Speeds earlier than the first curtain having accomplised full travel?

br gusti

There is a flash signal even at higher shutter speeds, but unless you switch to high speed flash use, the image will be vignetted if you try to use a flash above the sync speed.

Here are four pictures demonstrating what I mean.



This is taken at the sync speed, 1/200s and I had an old manual flash on the camera.



The next is taken at 1/250s, no vignetting with this flash because it can actually handle up to 1/320s normally.



This is what happens when you go faster, this one is taken at 1/500s, and here the vignetting shows but the flash is fired, so there is a flash signal (X-contact close as you call it).



As the shutter speed increase, the slit of the shutter gets narrower.

This continues until 1/8000s with the mechanical shutter and 1/2000s with the electronic first curtain. The fully electronic shutter does not give the X-signal, which is why I had to take an image of my timer automatically with the camera.

I guess that's what you mean by your question, but ask again if I misunderstood you.

no, thanks, this is what I meant and Jim had it already adressed.

thank you both!

my take away from this thread is:

1) Jims measurements on sony, results correlating to those of Imaging resource

Show differernt lag time for mech shutter and EFCs (roughly 90ms vs 24ms).

2) your measurements on Nikon z, results correlating to those of Imaging resource

Show nearly same lag time for mech shutter and EFCs (roughly 60ms vs 60ms).

3) travel time of mech curtain and also for EFC is 4ms for modern cams with short sync Speed

4 msec fo Z7, more like 2.5 or 3 Msec for D850 and D5.

4) big part of shutter lag seems to come from closure of shutter and resetting the sensor before start of exposure.

Resetting the sensor can be very fast, and even with a rolling reset when not using EFCS, it only needs to be ahead of the mechanical shutter. So the reset time is not going to affect the latency.

considering the short time shutters Need to move as per 3) , there ssems to be a different way of resetting sensor/emptying Pixel charge between sony and Nikon z,

I don't see why that needs to be the case. I think it is more likely a difference in the way the mechanical shutter works.

I do guess based on the remarkable differenc in EFCS lag between sony and Nikon.

thanks for the interesting Details and discussion!

br gusti

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