I saw this discussed a bit in the main A7CII thread but have any reviewers tested or posted examples of the EFCS vs electronic shutter bokeh with fast lenses and high shutter speeds? Neither sound like ideal options when using fast portrait lenses wide open and high shutter speeds (1/4000). I've also been considering the ZV-E1 as I'm doing more video these days. I'm curious how the fully electronic shutter on that with it's faster readout speed would compare to the EFCS or e-shutter on the A7CII. While 12mp is pretty lackluster for photos it may make more sense if fast lenses have issues on the A7CII (+ all the video advantages, lack of shutter wear, etc.)
Full mechanical shutter = both curtains travel in front of the sensor at the same distance = no problems.
Full electronic shutter, so called e-shutter = both curtains travel directly on the sensor = same distance = no problems.
EFCS (Electronic First Curtain Shutter) = first electronic curtain travel on the sensor plane and the second mechanical curtain travel a few millimetre in front of the sensor = not the same distance = can cause problems due to some odd light sneaking in at an angle between the curtains due to the distance difference (there was a good schematic and explanation at DPR long ago that showed this in detail how it happened).
The problem here manifest itself as more nervous bokeh typically, and also chopped of bokeh balls (meaning non round highlight circles). This happens at high shutter speeds (when the shutter only has a slit open that travels over the sensor surface) and with fast wide open lenses. Not otherwise.
In general e-shutters read out row after row top to bottom one row at the time. That process happens on "normal" (non stacked) sensors at around 1/15-1/60 of a second depending on make and model. For moving subjects this means that things can have moved between the first and last line is read out. Even if you shot at 1/8000 since that is the time each line is exposed. Also if you move the camera due to shake or panning you will get the jello effect.
E-shutters on stacked sensors typically reads out between 1/160 and 1/250 which makes less problems with moving subjects. Some reads out several lines at once, so they are reading in chunks. Some can sync with flash also.
One can get banding when one uses EFCS or E-shutter with HSS flash and also with LED-lights even with a stacked sensor in rare cases.
In even rarer cases banding and jello effects can also happen with mechanical shutters. They typically travel from top to bottom at the flash sync speed, often 1/250 but some cameras have lower like 1/160 and in the analog days 1/60 wasn't unusual. And before that they were even slower, there are some really cool shots available online with racing cars shot about 100 years ago which on the pictures have oval wheels and leaning telephone poles in the background due to the panning.
And before you say, but how can the first curtain of a normal slow readout sensor in EFCS shutter mode keep up with the mechanical rear curtain that does 1/250? And the answer is that it is the read out (saving) in e-shutters that takes time (usually 1/15-1/60 if non stacked). Opening the first electronic curtain on a normal sensor can be done as fast as the rear curtain can do its travel (1/160-1/250).
As for how different aperture / shutter speeds combos bokeh distortion looks, there used to be some examples found if one google it.
The day we get global shutters (all pixels read out at the same time) we will get rid of these problems.
I believe that this is an excellent and thorough explanation of the processes and the effects under varying circumstances of the different types of shutter. Deserves to be bookmarked.
One point did occur to me while reading through lattesweden's account.
The EFCS effect on bokeh, which occurs when EFCS is used with very wide apertures at very high shutter speeds, takes place because the mechanical second curtain is a few millimeters in front of the plane of the sensor where the electronic first curtain is located. So the two shutters are not in the same plane, allowing light effects under the limited circumstances that may produce bokeh effects, as light sneaks into the space between the electronic and the mechanical curtains. The bokeh effects with max ap and hi speed occur specifically because of the distance between the two curtains.
This suggests that the closer the mechanical shutter is to the sensor, the less any bokeh effects would be. Different camera bodies may vary in this distance and therefore any EFCS effects would also be variable in different bodies.
Furthermore, reducing this distance might well become a design goal in the engineering of a camera body. Given that the A7Cxx bodies are designed to be small, I wonder whether the distance between the sensor plane and the plane of the mechanical shutter might have been reduced by intent in the camera bodies, with the effect of reducing any EFCS bokeh effects and also helping to make the camera smaller. This would certainly be a desirable design goal for Sony in a camera that operates with a EFCS shutter and without a full mechanical shutter and that is designed to be as small as possible. It is possible that this design goal would be facilitated by the absence of a full mechanical shutter.
Whether the shutter-sensor distance has been reduced and whether the EFCS bokeh effect is therefore less in the A7Cxx bodies than in other camera bodies is an empirical question that will have to await someone doing careful tests (or for Sony to declare its engineering design on this point).
chiron wrote:
I believe that this is an excellent and thorough explanation of the processes and the effects under varying circumstances of the different types of shutter. Deserves to be bookmarked.
One point did occur to me while reading through lattesweden's account.
The EFCS effect on bokeh, which occurs when EFCS is used with very wide apertures at very high shutter speeds, takes place because the mechanical second curtain is a few millimeters in front of the plane of the sensor where the electronic first curtain is located. So the two shutters are not in the same plane, allowing light effects under the limited circumstances that may produce bokeh effects, as light sneaks into the space between the electronic and the mechanical curtains. The bokeh effects with max ap and hi speed occur specifically because of the distance between the two curtains.
This suggests that the closer the mechanical shutter is to the sensor, the less any bokeh effects would be. Different camera bodies may vary in this distance and therefore any EFCS effects would also be variable in different bodies.
Furthermore, reducing this distance might well become a design goal in the engineering of a camera body. Given that the A7Cxx bodies are designed to be small, I wonder whether the distance between the sensor plane and the plane of the mechanical shutter might have been reduced by intent in the camera bodies, with the effect of reducing any EFCS bokeh effects and also helping to make the camera smaller. This would certainly be a desirable design goal for Sony in a camera that operates with a EFCS shutter and without a full mechanical shutter and that is designed to be as small as possible. It is possible that this design goal would be facilitated by the absence of a full mechanical shutter.
Whether the shutter-sensor distance has been reduced and whether the EFCS bokeh effect is therefore less in the A7Cxx bodies than in other camera bodies is an empirical question that will have to await someone doing careful tests (or for Sony to declare its engineering design on this point). ...Show more →
I guess many parameters can affect.
One thing with EFCS we haven't mentioned is that one can get uneven lit images with it, especially viewable in blue cloud less skies, since the first e-curtain and the second mech-curtain can glide a little in how large the slit is and by that causing uneven exposure. Now this can happen on full mech shutters as well if they are a little out of alignment. Also mech shutters are affected by acceleration and deacceleration which e-curtains don't have unless they are programmed to also have.
Full e-shutters should therefor be best from this uneven exposure problem perspective. Sony seems to sync something with the lens as well in EFCS mode to mitigate this problem. Meaning lenses without electronic contacts seems to be more affected by the uneven sky problem than those who talks to the body.
Full mech shutters also seems to get more problems with light leaks. How many bright curved arcs haven't we seen in peoples images taken at high shutter speeds over the years, where the reason behind this is that one of the blades have developed a crack by rubbing itself against the other curtains blades. With EFCS there is only one mech curtain and the risk for light leaks developing should be less.
Also full mech shutters on mirrorless have a delay before firing. This since the sensor is in video mode = shutter open when it drives the live view image to the EVF/LCD. When you take an image then, the shutter must first close and then the first mech curtain can open again. This is why a full mech shutter sound almost like two images are taken. In EFCS mode, the sensor just cuts the live view and then the first e-curtain opens and exposure begins which is much faster.
DSLRs didn't have this problem since the image was linked to the user via the mirror and the shutter was closed all the time.
I was in my first text already about to write that it should be possible that the bokeh problem effect differs between cameras just for the reason you mention: that where the mech shutter is placed in distance from the sensor might be different in different models and that should change how much or little the bokeh is affected.
Also the mech shutter curtains are actually at a small distance difference since they overlap each other, but I think we can neglect that.
In general you will never get the mech shutter curtains closer to the sensor itself than the sensor cover glass (with the filters) allows. And we know this differs between brands, but if those small differences really shows I don't know.
Anyway for the record: Sony uses around 2 mm in cover glass thickness. And m4/3 use 4 mm (which is one reason dust doesn't show as much since it comes further away from the sensor). Nikon Z uses around 1.6 mm I think and also Leica L-mount uses something around that also, this so that their old vintage lenses also works well. Those where designed for film that didn't have a cover glass in front of the film at all and the sensor glass that is used in digital bodys acts a little like a lens, especially in the corners where light comes in at an angle (how much angle can differ depending on several things that I'll address below). A greater (bigger) angle shining light through the cover glass alters the lights focus a little which makes the corners soft.
Modern lenses are designed to take the cover glass thickness into account and is therefor not affected by this. But if you take a lens from one system and mount on another with another cover glass thickness you could get a performance difference.
Our bokeh problem is also dealing with angled light, but if the sensor glass thickness affects bokeh distortion I don't know.
Cover glass thickness is more sensitive on Leica M-mount lenses since they have a rather short flange distance between the lens and the film (they could do this since they didn't have a mirror that needed space). So M-mount lenses sits closer to a sensor as well vs how close DSLR lenses sits and performs on digital sensors since those where made to sit further away from the film/sensor plane and thus the light angle is not as step.
Also the lens type differs (wide, normal, tele) and lens design in how close the rear element sits to the sensor where wide angles often have their rear element closer to the sensor and the light by that shines on the sensor from a greater angle into the corners.
Different mirrorless systems have different distance between mount and sensor where Sony uses 18 mm and Nikon 16 mm and Canon RF and L-mount is at 20 mm if I remember correct. This can affect as well but one can put the rear element far away from the sensor anyway by design even if the flange distance is short. Basically the rear of the lens can just be like a tube and the rear element is then far away from the sensor and the light beams that shines on the sensor are then more parallel.
One can imagine by guessing a little that more parallel beams onto the sensor should lower the risk for light sneaking in the wrong way between the two EFCS shutter curtains that are at different distances to the sensor, but if that is true in the real world is more than I know.
I have on my A7RII and the Sony/Zeiss 35/1.4 experienced chopped off bokeh balls at f1.4 and 1/4000 seconds shutter speed in EFCS mode. Going over to full mech shutter fixed it. I could probably just as well used the slow read out e-shutter to fix that problem since I shot a flower in daylight.
And this is actually the best way to see what all the above theories actually translate to. Just take a body with full mech shutter and test that at different apertures and shutter speeds and then do the same test with full e-shutter and finally in EFCS mode.
As with everything in photography one has to choose between different compromises. This goes in everything in photography actually. It is quite much like the Swedish saying: You must choose between the Plague and Cholera.
lattesweden wrote:
I guess many parameters can affect.
One thing with EFCS we haven't mentioned is that one can get uneven lit images with it, especially viewable in blue cloud less skies, since the first e-curtain and the second mech-curtain can glide a little in how large the slit is and by that causing uneven exposure. Now this can happen on full mech shutters as well if they are a little out of alignment. Also mech shutters are affected by acceleration and deacceleration which e-curtains don't have unless they are programmed to also have.
Full e-shutters should therefor be best from this uneven exposure problem perspective. Sony seems to sync something with the lens as well in EFCS mode to mitigate this problem. Meaning lenses without electronic contacts seems to be more affected by the uneven sky problem than those who talks to the body.
Full mech shutters also seems to get more problems with light leaks. How many bright curved arcs haven't we seen in peoples images taken at high shutter speeds over the years, where the reason behind this is that one of the blades have developed a crack by rubbing itself against the other curtains blades. With EFCS there is only one mech curtain and the risk for light leaks developing should be less.
Also full mech shutters on mirrorless have a delay before firing. This since the sensor is in video mode = shutter open when it drives the live view image to the EVF/LCD. When you take an image then, the shutter must first close and then the first mech curtain can open again. This is why a full mech shutter sound almost like two images are taken. In EFCS mode, the sensor just cuts the live view and then the first e-curtain opens and exposure begins which is much faster.
DSLRs didn't have this problem since the image was linked to the user via the mirror and the shutter was closed all the time.
I was in my first text already about to write that it should be possible that the bokeh problem effect differs between cameras just for the reason you mention: that where the mech shutter is placed in distance from the sensor might be different in different models and that should change how much or little the bokeh is affected.
Also the mech shutter curtains are actually at a small distance difference since they overlap each other, but I think we can neglect that.
In general you will never get the mech shutter curtains closer to the sensor itself than the sensor cover glass (with the filters) allows. And we know this differs between brands, but if those small differences really shows I don't know.
Anyway for the record: Sony uses around 2 mm in cover glass thickness. And m4/3 use 4 mm (which is one reason dust doesn't show as much since it comes further away from the sensor). Nikon Z uses around 1.6 mm I think and also Leica L-mount uses something around that also, this so that their old vintage lenses also works well. Those where designed for film that didn't have a cover glass in front of the film at all and the sensor glass that is used in digital bodys acts a little like a lens, especially in the corners where light comes in at an angle (how much angle can differ depending on several things that I'll address below). A greater (bigger) angle shining light through the cover glass alters the lights focus a little which makes the corners soft.
Modern lenses are designed to take the cover glass thickness into account and is therefor not affected by this. But if you take a lens from one system and mount on another with another cover glass thickness you could get a performance difference.
Our bokeh problem is also dealing with angled light, but if the sensor glass thickness affects bokeh distortion I don't know.
Cover glass thickness is more sensitive on Leica M-mount lenses since they have a rather short flange distance between the lens and the film (they could do this since they didn't have a mirror that needed space). So M-mount lenses sits closer to a sensor as well vs how close DSLR lenses sits and performs on digital sensors since those where made to sit further away from the film/sensor plane and thus the light angle is not as step.
Also the lens type differs (wide, normal, tele) and lens design in how close the rear element sits to the sensor where wide angles often have their rear element closer to the sensor and the light by that shines on the sensor from a greater angle into the corners.
Different mirrorless systems have different distance between mount and sensor where Sony uses 18 mm and Nikon 16 mm and Canon RF and L-mount is at 20 mm if I remember correct. This can affect as well but one can put the rear element far away from the sensor anyway by design even if the flange distance is short. Basically the rear of the lens can just be like a tube and the rear element is then far away from the sensor and the light beams that shines on the sensor are then more parallel.
One can imagine by guessing a little that more parallel beams onto the sensor should lower the risk for light sneaking in the wrong way between the two EFCS shutter curtains that are at different distances to the sensor, but if that is true in the real world is more than I know.
I have on my A7RII and the Sony/Zeiss 35/1.4 experienced chopped off bokeh balls at f1.4 and 1/4000 seconds shutter speed in EFCS mode. Going over to full mech shutter fixed it. I could probably just as well used the slow read out e-shutter to fix that problem since I shot a flower in daylight.
And this is actually the best way to see what all the above theories actually translate to. Just take a body with full mech shutter and test that at different apertures and shutter speeds and then do the same test with full e-shutter and finally in EFCS mode.
As with everything in photography one has to choose between different compromises. This goes in everything in photography actually. It is quite much like the Swedish saying: You must choose between the Plague and Cholera.
AlphaPhotography wrote:
I saw this discussed a bit in the main A7CII thread but have any reviewers tested or posted examples of the EFCS vs electronic shutter bokeh with fast lenses and high shutter speeds? Neither sound like ideal options when using fast portrait lenses wide open and high shutter speeds (1/4000). I've also been considering the ZV-E1 as I'm doing more video these days. I'm curious how the fully electronic shutter on that with it's faster readout speed would compare to the EFCS or e-shutter on the A7CII. While 12mp is pretty lackluster for photos it may make more sense if fast lenses have issues on the A7CII (+ all the video advantages, lack of shutter wear, etc.)...Show more →
This video has the most realistic examples I think, the last example being the most noticeable. The video in the first post also has more examples and includes Mark Galer's opinion where he actually prefers the EFCS bokeh.
lattesweden wrote:
I guess many parameters can affect.
One thing with EFCS we haven't mentioned is that one can get uneven lit images with it, especially viewable in blue cloud less skies, since the first e-curtain and the second mech-curtain can glide a little in how large the slit is and by that causing uneven exposure. Now this can happen on full mech shutters as well if they are a little out of alignment. Also mech shutters are affected by acceleration and deacceleration which e-curtains don't have unless they are programmed to also have.
Full e-shutters should therefor be best from this uneven exposure problem perspective. Sony seems to sync something with the lens as well in EFCS mode to mitigate this problem. Meaning lenses without electronic contacts seems to be more affected by the uneven sky problem than those who talks to the body.
Full mech shutters also seems to get more problems with light leaks. How many bright curved arcs haven't we seen in peoples images taken at high shutter speeds over the years, where the reason behind this is that one of the blades have developed a crack by rubbing itself against the other curtains blades. With EFCS there is only one mech curtain and the risk for light leaks developing should be less.
Also full mech shutters on mirrorless have a delay before firing. This since the sensor is in video mode = shutter open when it drives the live view image to the EVF/LCD. When you take an image then, the shutter must first close and then the first mech curtain can open again. This is why a full mech shutter sound almost like two images are taken. In EFCS mode, the sensor just cuts the live view and then the first e-curtain opens and exposure begins which is much faster.
DSLRs didn't have this problem since the image was linked to the user via the mirror and the shutter was closed all the time.
I was in my first text already about to write that it should be possible that the bokeh problem effect differs between cameras just for the reason you mention: that where the mech shutter is placed in distance from the sensor might be different in different models and that should change how much or little the bokeh is affected.
Also the mech shutter curtains are actually at a small distance difference since they overlap each other, but I think we can neglect that.
In general you will never get the mech shutter curtains closer to the sensor itself than the sensor cover glass (with the filters) allows. And we know this differs between brands, but if those small differences really shows I don't know.
Anyway for the record: Sony uses around 2 mm in cover glass thickness. And m4/3 use 4 mm (which is one reason dust doesn't show as much since it comes further away from the sensor). Nikon Z uses around 1.6 mm I think and also Leica L-mount uses something around that also, this so that their old vintage lenses also works well. Those where designed for film that didn't have a cover glass in front of the film at all and the sensor glass that is used in digital bodys acts a little like a lens, especially in the corners where light comes in at an angle (how much angle can differ depending on several things that I'll address below). A greater (bigger) angle shining light through the cover glass alters the lights focus a little which makes the corners soft.
Modern lenses are designed to take the cover glass thickness into account and is therefor not affected by this. But if you take a lens from one system and mount on another with another cover glass thickness you could get a performance difference.
Our bokeh problem is also dealing with angled light, but if the sensor glass thickness affects bokeh distortion I don't know.
Cover glass thickness is more sensitive on Leica M-mount lenses since they have a rather short flange distance between the lens and the film (they could do this since they didn't have a mirror that needed space). So M-mount lenses sits closer to a sensor as well vs how close DSLR lenses sits and performs on digital sensors since those where made to sit further away from the film/sensor plane and thus the light angle is not as step.
Also the lens type differs (wide, normal, tele) and lens design in how close the rear element sits to the sensor where wide angles often have their rear element closer to the sensor and the light by that shines on the sensor from a greater angle into the corners.
Different mirrorless systems have different distance between mount and sensor where Sony uses 18 mm and Nikon 16 mm and Canon RF and L-mount is at 20 mm if I remember correct. This can affect as well but one can put the rear element far away from the sensor anyway by design even if the flange distance is short. Basically the rear of the lens can just be like a tube and the rear element is then far away from the sensor and the light beams that shines on the sensor are then more parallel.
One can imagine by guessing a little that more parallel beams onto the sensor should lower the risk for light sneaking in the wrong way between the two EFCS shutter curtains that are at different distances to the sensor, but if that is true in the real world is more than I know.
I have on my A7RII and the Sony/Zeiss 35/1.4 experienced chopped off bokeh balls at f1.4 and 1/4000 seconds shutter speed in EFCS mode. Going over to full mech shutter fixed it. I could probably just as well used the slow read out e-shutter to fix that problem since I shot a flower in daylight.
And this is actually the best way to see what all the above theories actually translate to. Just take a body with full mech shutter and test that at different apertures and shutter speeds and then do the same test with full e-shutter and finally in EFCS mode.
As with everything in photography one has to choose between different compromises. This goes in everything in photography actually. It is quite much like the Swedish saying: You must choose between the Plague and Cholera.
AlphaPhotography wrote:
... but have any reviewers tested or posted examples of the EFCS vs electronic shutter bokeh with fast lenses and high shutter speeds?...
People keep saying fast shutter speed truncate the bokeh balls with EFCS. The real question is: how fast is it? I looked around and some sources say above 1/1000 second. Is anyone here meticulous enough to test the effect of EFCS on bokeh at different shutter speeds? Thanks.
The person who's name is at the very top of this forum did exactly that. 😊
Generally speaking, anything over 1/1000 and faster than 1.8 will cause it.
withoutid wrote:
People keep saying fast shutter speed truncate the bokeh balls with EFCS. The real question is: how fast is it? I looked around and some sources say above 1/1000 second. Is anyone here meticulous enough to test the effect of EFCS on bokeh at different shutter speeds? Thanks.
maestrofilms wrote:
The person who's name is at the very top of this forum did exactly that. 😊
Generally speaking, anything over 1/1000 and faster than 1.8 will cause it.
We did this a long time ago and it was at 1/1000 and faster but we never tested it on different bodies either which could be related. Bottom line and most everyone will say this we know of the issue and it is real so either pay attention to it or not. For me its not the biggest issue and don't run into it that often , my shooting is pretty controlled so it is in my head but not so much in the actual shooting in this area. My concerns runs past most hobbyists shooting and more weird stuff like LED/Florsecent and Flash work so Im more concentrated on mechnical shutter /varible shutter/ led control and things at this level
So I may have been doing everything exactly backwards with my a1...
I have three dialed settings:
1. Landscape - mechanical shutter regardless of shutter speed. Thought I read this would offer the best image but glossed over shutter shock especially on the 70-200 at slow speeds... So now think this should always be electronic shutter
2. Portrait - electronic shutter and don't use flash ever
3. High school football - electronic shutter with 1/1000-1/1250 at f/2.8 and auto ISO. I thought the electronic shutter was the only way to get 30 fps with the 70-200/2.8 using compressed raw and a CF card.
So how did I do for the a1? Sorry OP who asked about others but the first reply had me worried I was doing it wrong.
Sep 21, 2023 at 02:03 PM
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eyal wrote:
So I may have been doing everything exactly backwards with my a1...
I have three dialed settings:
1. Landscape - mechanical shutter regardless of shutter speed. Thought I read this would offer the best image but glossed over shutter shock especially on the 70-200 at slow speeds... So now think this should always be electronic shutter
2. Portrait - electronic shutter and don't use flash ever
3. High school football - electronic shutter with 1/1000-1/1250 at f/2.8 and auto ISO. I thought the electronic shutter was the only way to get 30 fps with the 70-200/2.8 using compressed raw and a CF card.
So how did I do for the a1? Sorry OP who asked about others but the first reply had me worried I was doing it wrong....Show more →
I think you can simply the A1 to: use the electronic shutter unless you want to use flash sync with higher shutter speeds (i.e., greater than 1/200 up to 1/400).
withoutid wrote:
People keep saying fast shutter speed truncate the bokeh balls with EFCS. The real question is: how fast is it? I looked around and some sources say above 1/1000 second. Is anyone here meticulous enough to test the effect of EFCS on bokeh at different shutter speeds? Thanks.
There is a difference between when it is perceptible, which is largely subjective and dependent on the scene, and when it starts having an effect.
The former is a very contentious topic, some even preferring the new rendering. But for the latter, it affects exposures as slow as 1/125s on APS-C, see this link from above. The difference images are pretty small, but it is actual light being removed:
maestrofilms wrote:
The person who's name is at the very top of this forum did exactly that. 😊
Generally speaking, anything over 1/1000 and faster than 1.8 will cause it.
What if I want to shoot 85mm f/1.4 at f/1.4? I can always use an ND filter to bring down the shutter speed. Will the quality of bokeh be bad when the f/1.4 at 1/500s?
lsquare wrote:
What if I want to shoot 85mm f/1.4 at f/1.4? I can always use an ND filter to bring down the shutter speed. Will the quality of bokeh be bad when the f/1.4 at 1/500s?
