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Fuji X-T2 - strange lines on photos


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Using the E shutter in artificial light? If so then that is likely the problem. Use manual shutter or take some shots and adjust shutter speed until the scan lines don't show. Artificial light is like TV screens - at certain shutter speeds the scan lines will show. If the shutter is too fast the lines will show even with M shutter.

BTW. Not a Fuji thing - same with all cameras but seems to be worse with E shutter due to the time it takes for the E shutter to move across he frame.

If possible, when including a picture, always include the exif info.

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Agree with VJC, this type of problem is commonly caused by electronic shutter and artificial light (the electronic shutter means the exposure is controlled via the sensor.  the sensor does not have a "global electronic shutter", and therefore cannot read the entire image off the sensor at once - it has to read it line by line - this takes time, a surprisingly long time like 0.3 seconds or something - as a result, the image can capture changes to light such as someones camera flash or the natural main frequency flickering or artificial light.

Electronic first curtain shutter can also have some issues in some situations.  Mechanical shutter can create issues with mains based artificial light when the shutter speed is below the mains frequency (e.g. mains is 50Hz, shutter speed is 1/30s) as the exposure will capture the "flickering" of the light and can cause strobe effects.

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9 hours ago, artuk said:

Agree with VJC, this type of problem is commonly caused by electronic shutter and artificial light (the electronic shutter means the exposure is controlled via the sensor.  the sensor does not have a "global electronic shutter", and therefore cannot read the entire image off the sensor at once - it has to read it line by line - this takes time, a surprisingly long time like 0.3 seconds or something - as a result, the image can capture changes to light such as someones camera flash or the natural main frequency flickering or artificial light.

Electronic first curtain shutter can also have some issues in some situations.  Mechanical shutter can create issues with mains based artificial light when the shutter speed is below the mains frequency (e.g. mains is 50Hz, shutter speed is 1/30s) as the exposure will capture the "flickering" of the light and can cause strobe effects.

 

 

Aren't electronic shutters basically worthless except for still life shot from tripods?

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1 hour ago, farrell said:

 

 

Aren't electronic shutters basically worthless except for still life shot from tripods?

No.

Electronic first curtain is mostly problem free for stills, but has the benefit that it decreases shutter lag since there is no need to close and then re-open the shutter.  This is a benefit as the enhanced shutter response time alleviates some of the problems caused by the delay in EVF viewfinder systems.

Full electronic shutter depends on implementation.  In the new Sony A9, the sensor is engineered to be able to fire the shutter and still provide a real time live view in the viewfinder.  Although Sony do not claim it supports global electronic shutter, it is so close for stills that it provides no issues that I have heard about.

Other (older) sensors that support full electronic shutter still have advantages in some situations, where fast action or artificial light are not used.  I sometimes use full electronic shutter for available light photos at night when I want to shoot silently.

You don't need still life, nor a tripod - the only major issues are changing light -  in this example where it looks like a flash has fired during sensor read out, or where artificial light is "flickering".  VJC also found some issues with some bird photos he took in his garden - I cant remember the exact circumstances.

It is probably worth noting that the Sony sensor that Fuji is using, in it's non Fuji implementation, has not been used to provide electronic shutter with such high shutter speeds (it has been used with full electronic shutter, but only within "normal" shutter speed ranges).  It is possible, though not likely, that the version manufactured for Fuji has different or enhanced functionality, and therefore the Fuji implementation may be "pushing the envelope" of what the sensor can do, introducing some issues.

It's also worth noting that to date, most Sony made sensors that support full electronic shutter reduce the bit depth of the raw file when used - which results in lower dynamic range and the potential for issues when pushing the files very hard in post processing.  As a result, where pure quality matters, it is generally best to avoid the mode unless absolute silence is mandatory.

I am convinced that within the next 1 or  2 sensor generations we will see full electronic shutter being "normal", and therefore removing the need to a mechanical shutter, reducing the mechanical complexity of cameras even more.  In mirrorless, the shutter is the last remaining piece of fine engineering.

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In the US power is 60hz in most of the rest of the world it's 50hz. What that means is that halogen and fluro lights in particular pulse at either 60 or 50 times a second. The human eye does not see the pulses. If your shutter speed is an exact multiple of the hz rate say 1/60, 1/120 or 1/50, 1/100 sec then that is where these strange lines tend to appear.

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I mostly use my XT2/XT20 with E shutter now. I am aware though that if the subject has any part that is moving quickly I need to use M shutter. When I say "moving quickly" I include things such as the forward swinging arm/leg of a forward walking person but even then if the shutter is higher than about 1/250 with lens 35mm and under you should be okay with E shutter. No science involved there - just trial and error.

I use E shutter for street and general people pics.

As Artuk mentions above, I had problems with a swaying bird feeder but I put it down to my unbalanced stance and camera movement (with a 300mm lens) more than subject movement.

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2 hours ago, veejaycee said:

I mostly use my XT2/XT20 with E shutter now. I am aware though that if the subject has any part that is moving quickly I need to use M shutter. When I say "moving quickly" I include things such as the forward swinging arm/leg of a forward walking person but even then if the shutter is higher than about 1/250 with lens 35mm and under you should be okay with E shutter. No science involved there - just trial and error.

I use E shutter for street and general people pics.

As Artuk mentions above, I had problems with a swaying bird feeder but I put it down to my unbalanced stance and camera movement (with a 300mm lens) more than subject movement.

Any kind of movement, including camera movement that is exaggerated by using long tele lenses, will potentially affect the image due to the relatively slow read out speed.

2 hours ago, K1W1_Mk2 said:

In the US power is 60hz in most of the rest of the world it's 50hz. What that means is that halogen and fluro lights in particular pulse at either 60 or 50 times a second. The human eye does not see the pulses. If your shutter speed is an exact multiple of the hz rate say 1/60, 1/120 or 1/50, 1/100 sec then that is where these strange lines tend to appear.

I think that's true for mechanical shutter.  With electronic shutter, I *think* it is an issue because of the sensor read out speed, which is independent of the actual shutter speed used.

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7 minutes ago, atanas.b said:

Thank you all for the information!

The shutter speed is 1/250s with the Fujinon 50mm f/2.

The problem with Fuji's implementation of fully electronic shutter is that regardless of what shutter speed you use - up to the maximum of 1/32,000 - the sensor takes a fixed amount of time to end the exposure by reading all the data off the sensor, line by line.  This is actually a very long time, and can be much longer than the actual shutter speed (I seem to remember 300ms, that is 1/3s, but I may have remembered that incorrectly, so don't quote me on that value).  As the sensor is being read to "end" the exposure, it is still active, and therefore as it is read from line by line, any changes in light hitting the scene will be recorded (there is no mechanical shutter used to end the exposure and shield the sensor).  What your photo is probably showing is that whilst that strip of brighter line was being read, someone's flash fired and lit the scene, and your camera recorded it as that section of the sensor was being read.  That a flash firing will create a bright band as the electronic shutter is "closing" the exposure shows how relatively slowly the sensor reads - the flash can fire, light the scene, and stop within perhaps 1/8th of the time that the sensor read out took (you could probably fit 8 of those bands into the height of the frame).

The issue is that Fuji have implemented the camera with a full electronic shutter, offering speeds up to 1/32000s when the sensor read out is very slow in comparison.  As VJC found, when he used a long tele lens, although his fast shutter speed froze the action, the sensor readout time appeared to cause ghosting or blurring because in the time it took to read the sensor, there was camera shake.  Therefore the ability to use very high shutter speeds sets an expectation in the user that the camera may struggle to meet.  I am actually unsure how the camera can shoot at 1/32000s and end the exposure correctly when the sensor is still active whilst being read and can therefore record light and movement - because it implies the shortest electronic shutter speed is logically the read out speed of the sensor, say 1/3s, which is much longer than 1/32000s! Clearly, there is something else at play that I am not understanding - perhaps the sensor turns on line by line at the start of the exposure too, therefore allowing each row to be exposed for the correct time.

All of this is because the sensor does not offer a "global electronic shutter" with full sensor read out simultaneously from every row.  The only sensor that comes close to this is the new Sony BSI full frame unit found in the Sony A9 camera, which although is doesn't have a "global" shutter is reported to have a "high speed shutter", that supposedly is achieved because the sensor can read out 20 times faster that previous designs. 

All of the above is what causes the issue of "jello effect" in video, where panning the camera causes straight lines to appear to become bent due to the movement of the camera and the sensor read out speed.  It also causes aeroplane propellers to look "bent" when spinning on video with such cameras. 

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On 9/4/2017 at 3:50 AM, artuk said:

The problem with Fuji's implementation of fully electronic shutter is that regardless of what shutter speed you use - up to the maximum of 1/32,000 - the sensor takes a fixed amount of time to end the exposure by reading all the data off the sensor, line by line.  This is actually a very long time, and can be much longer than the actual shutter speed (I seem to remember 300ms, that is 1/3s, but I may have remembered that incorrectly, so don't quote me on that value).  As the sensor is being read to "end" the exposure, it is still active, and therefore as it is read from line by line, any changes in light hitting the scene will be recorded (there is no mechanical shutter used to end the exposure and shield the sensor).  What your photo is probably showing is that whilst that strip of brighter line was being read, someone's flash fired and lit the scene, and your camera recorded it as that section of the sensor was being read.  That a flash firing will create a bright band as the electronic shutter is "closing" the exposure shows how relatively slowly the sensor reads - the flash can fire, light the scene, and stop within perhaps 1/8th of the time that the sensor read out took (you could probably fit 8 of those bands into the height of the frame).

The issue is that Fuji have implemented the camera with a full electronic shutter, offering speeds up to 1/32000s when the sensor read out is very slow in comparison. 

I don't claim to understand the technical side of things, but if the reading time is slow, why not just expose every pixel and turn it off in the given interval (1/32k etc.) but then use the slower readout to read the pixels? Or perhaps it cannot be decoupled and the 'turning off' is done during the readout. 

If what you say is true, then it is not really 1/32K ES anyway, since one 'sees' artifacts in the picture that do not fit in the specified (or chosen) time interval. And we all agree to this mediocrity by extolling the virtues of the feature list of our cameras that includes ES. :) 

Interesting how marketing department can even bend a measurable time window into something fluid akin to Einstein's relativity. In that sense, they may be the true geniuses. ;)  

 

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56 minutes ago, raagamuffin said:

I don't claim to understand the technical side of things, but if the reading time is slow, why not just expose every pixel and turn it off in the given interval (1/32k etc.) but then use the slower readout to read the pixels? Or perhaps it cannot be decoupled and the 'turning off' is done during the readout. 

If what you say is true, then it is not really 1/32K ES anyway, since one 'sees' artifacts in the picture that do not fit in the specified (or chosen) time interval. And we all agree to this mediocrity by extolling the virtues of the feature list of our cameras that includes ES. :) 

Interesting how marketing department can even bend a measurable time window into something fluid akin to Einstein's relativity. In that sense, they may be the true geniuses. ;)  

 

From what I understand, "clearing down" the sensor is what effectively turns it "off".  Modern sensors read data from pixels line by line (lines generally seem to across the sensor width), and each column of data is read off (all pixels in that column read near simultaneously), and the electrical signal than being passed to the analogue-to-digital convertor on the back of the sensor (Sony sensors use large scale integration to put the processor for the D-A very close to the sensor itself, minimising signals paths and therefore lowering read noise and increasing DR).  I can only assume that with electronic front curtain, when the exposure starts, it also takes place line by line - which makes sense as it is exactly how mechanical shutters work, the front curtain sweeping across the sensor followed by the second curtain.  Therefore it's not that the sensor cannot start and stop the exposure for 1/32,000s between turning each row on and then off - but that the read speed means the "turning off" process takes place quite slowly as each row is read line by line (and therefore the turning on must also be at the same speed).  In effect, each row is only on for 1/32,000s, but the entire sensor takes (say) 300ms to turn each row on and then off - so there can be movement or issues with changing light levels of each individual row.  The rows are exposure "correctly", but what was recorded by a particular row may be different from ones before or after.

I generally always use EFC as it starts the exposure more quickly that mechanical front curtain, therefore improving the shutter response.  I have a couple of cameras that have fully electronic shutter as an option, but I only use it when absolutely necessary because of reduced noise, as it also lowers bit depth which can be an issue when working at high ISO values (3,200->25,600) as it may lower image quality.  AFAIK, the new 24Mp full frame sensor in the new Sony A9 is the only APS-C/FF stills camera sensor I know that comes close to global shutter.  I'm not sure about some of the m43rds and 1" sensors out there.

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8 hours ago, raagamuffin said:

I don't claim to understand the technical side of things, but if the reading time is slow, why not just expose every pixel and turn it off in the given interval (1/32k etc.) but then use the slower readout to read the pixels? Or perhaps it cannot be decoupled and the 'turning off' is done during the readout. 

If what you say is true, then it is not really 1/32K ES anyway, since one 'sees' artifacts in the picture that do not fit in the specified (or chosen) time interval. And we all agree to this mediocrity by extolling the virtues of the feature list of our cameras that includes ES. :) 

Interesting how marketing department can even bend a measurable time window into something fluid akin to Einstein's relativity. In that sense, they may be the true geniuses. ;)  

 

Certainly the Fuji implementation of the E shutter isn't perfect but like many other new things,  it is a step in the right direction and is most definitely worth using. - Just don't use it on fast moving vehicles otherwise this might happen -- by Jacques Henri Lartigue.

Jacques Henri Lartigue.jpg

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6 hours ago, veejaycee said:

Certainly the Fuji implementation of the E shutter isn't perfect but like many other new things,  it is a step in the right direction and is most definitely worth using. - Just don't use it on fast moving vehicles otherwise this might happen -- by Jacques Henri Lartigue.

Jacques Henri Lartigue.jpg

Cause vertically-traveling shutter curtains, or "cartoon wheels" effect.

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On 9/5/2017 at 5:51 PM, veejaycee said:

Certainly the Fuji implementation of the E shutter isn't perfect but like many other new things,  it is a step in the right direction and is most definitely worth using. - Just don't use it on fast moving vehicles otherwise this might happen -- by Jacques Henri Lartigue.

Jacques Henri Lartigue.jpg

I wonder if the original cartoon artists saw a rolling shutter photo and created the effect in their cartoons !

It does add a dimension to the picture that I hadn't considered previously, an air of hurriedness, which is difficult to convey even in pictures with longer exposure times (eg: the classic water flowing down a stream). 

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  • 2 weeks later...

You are talking this and that inconsequential, but nobody has mentioned that the light on the lighter stripe comes from the left, while the most part of the picture is lighted from the right. Thus:

Electronic shutter was used (with read speed of about 1/15 sec on Fuji, no matter what the "shutter speed" is), with a flash from another camera coming from the left.

Elementary, dear Watson!

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10 hours ago, Petrus said:

with a flash from another camera coming from the left

+1

It's a flash from another camera. Fluorescent lighting would have left several lines.

On 03/09/2017 at 11:10 PM, K1W1_Mk2 said:

In the US power is 60hz in most of the rest of the world it's 50hz. What that means is that halogen and fluro lights in particular pulse at either 60 or 50 times a second.

Light pulses at double frequency: 120 or 100 times a second.

On 03/09/2017 at 11:10 PM, K1W1_Mk2 said:

If your shutter speed is an exact multiple of the hz rate say 1/60, 1/120 or 1/50, 1/100 sec then that is where these strange lines tend to appear.

No, that's exactly how to make them DISAPPEAR.

The lines appear at high shutter speeds (1/200 sec for example). If you expose each pixel for a whole number of pulses, say in the US:

1 pulse 1/120 sec

2 pulses 1/60 sec

3 pulses 1/40 sec

then there will be no lines as each pixel receives the same amount of light.

10 hours ago, Petrus said:

with read speed of about 1/15 sec on Fuji, no matter what the "shutter speed" is

That was true for the X-T1 and X-E2. In the X-T2 and X-Pro2 the read out speed for electronic shutter is about 1/25 sec. If someone catches a flash with the X-T2 while using ES with a shutter speed of 1/250 sec, this flash will leave a light band about 10% of the height of the image. This is exactly what happened here.

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