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Silent shutter - take care or be creative

Robert Watcher

Well-known member
A photo that I took yesterday, reminded me of a situation that I came across this summer that I wasn't aware of. It is related to shooting with my Olympus E-M1 (I don't use it often with my street work) in Silent Shutter Mode.

I was sitting in a McDonalds here in Guatemala and grabbed a few natural light frames of people sitting there. Immediately I recognized the dark banding on the LCD screen - - - but it actually looked really cool. Like I was firing through blinds of some sort or the subject being lit by light streaming through blinds.

What I experienced earlier in the year when using the same camera at a concert in Ontario, is that one of the artifacts of using an electronic shutter (Silent Mode) in certain types of lighting - is this phenomena of dark lines going across the frame and interfering with the image. Of course when this happened at that time, I wasn't too happy and thought that I had a defective camera.

I soon came to the conclusion that it may be the electronic shutter and so when I went back to the normal shutter, the lines disappeared and the images were fine. I knew about issues with fluorescent and certain other artificial lights from shooting taking pics in hockey arenas in the past. So presumed that was causing the issue with the electronic shutter. SIMPLE SOLUTION - don't use it.

Here is the image that I took yesterday using the Silent Shutter - that reminded me of my previous experience - - - but that actually worked well creatively:


AP-20160912-PEM11237.jpg

 

Robert Watcher

Well-known member
A second shot taken yesterday, revealed what I suspected. The fluorescent lights were playing havoc. After taking the first capture using the Electronic Shutter, I changed to the Mechanical Shutter and the image cleaned up:


AP-20160912-PEM11244.jpg

Electronic Shutter Exposure 1/640'th second

AP-20160912-PEM11246.jpg

Mechanical Shutter Exposure 1/640'th second
 

Doug Kerr

Well-known member
Hi, Robert,

A second shot taken yesterday, revealed what I suspected. The fluorescent lights were playing havoc. After taking the first shot using the Electronic Shutter, I changed to the Manual shutter . . .

"Mechanical" shutter, maybe.

and the image cleaned up:

Interesting report, and a good caution.

Thanks.

Best regards,

Doug
 

Robert Watcher

Well-known member
SO NOW I WAS CURIOUS. I had to revisit the photos I took at the Folk Festival this past summer, and see if I could recognize patterns that would help me better understand how to make best use of the Silent Shutter - - - which I love using. At 9fps second it is crazy rattling off a ton of images in a few seconds without knowing you are even shooting.


Analyzing pics taken at different shutter speeds (because of the crazy light intensity changes that take place at concerts), I soon realized that faster shutter speeds intensified the problem. Slow shutter speeds of 1/40'th second and the like, did not exhibit any issues other than motion blur.

Where issues cropped up was with shutter speeds of 1/400'th of a second and higher. Pics taken at 1/160'th to 1/200'th may have some banding, but very subtle if there. Here are some examples:



AP-20160715-PEM10923.jpg

1/800'th second with Electronic Shutter


AP-20160715-PEM10924.jpg

1/200'th second with Electronic Shutter



An interesting find that I will have to test out if I ever feel the notion to - - - is that a few of the images show shutter speeds of 1,000'th to 1/2500'th second and there arrear to be no banding on them. It is hard for me to tell if those were taken after I went back to normal shutter, but I suspect they are also Silent Shutter.

One amazing feature with the Silent Shutter of the Olympus, is it's ability to extend the highest possible shutter speed to 1/16,000'th of a second from the normal high of 1/8,000'th of a second.
 

Robert Watcher

Well-known member
Now I would have to be really out there to consider these Silent Shutter artifacts to be cool and creative - but you never know. Interestingly when the camera is held vertically, the stripes now appear top to bottom.


AP-20160715-PEM10907.jpg

1/400'th second with Electronic Shutter


AP-20160715-PEM10906.jpg

1/200'th second with Electronic Shutter


Well lucky for me and my purchase of the Olympus E-M1 used this summer - this is not a problem to be concerned about. Just aware of. Checking online, it doesn't matter whether the brand is Sony, Panasonic or any other using Electronic Shutters - - - at higher shutter speeds under fluorescent lighting and maybe a few other fluctuating types of light, we can expect the banding.

But I'm glad I came across this yesterday and looked deeper into it. The issue is another tool that I have in my bag of Creative Options.


-----------
 

Doug Kerr

Well-known member
Hi, Robert,

One website even said that the shutter speed can be determined by how many bands are in the image.

Not likely. More likely, it indicates the sensor readout time, which is not the same as the "exposure time", which is what we usually mean by "shutter speed". (It is for example said to be 1/10 sec in the Lumix GH3, and 1/30 sec in the GH4.)

There is a nice discussion of this matter here:

http://m43photo.blogspot.com/2015/04/e-m5-ii-shutters.html

Best regards,

Doug
 

Robert Watcher

Well-known member
Hi, Robert,



Not likely. More likely, it indicates the sensor readout time, which is not the same as the "exposure time", which is what we usually mean by "shutter speed". (It is for example said to be 1/10 sec in the Lumix GH3, and 1/30 sec in the GH4.)

There is a nice discussion of this matter here:

http://m43photo.blogspot.com/2015/04/e-m5-ii-shutters.html

Best regards,

Doug

Again my lack of interest in technicalities Doug. I reread and what is being referred to is being able to calculate the light source varying its intensity by the number of bands. Determining example if 60Hz or 50 Hz mains power. So Jim Kasson explains. You would probably enjoy his take on it -

http://blog.kasson.com?p=11258


------
 

Michael Nagel

Active member
Robert - thanks for posting this and glad that you could use it.

Doug - thanks for your additions.

I am a bit wary of electronic shutters and prefer to rely on silent mechanical shutters like the X10 (or later models) if noise is not desired.
It depends a lot on the ambient noise, so relatively silent DSLRs like the Pentax K single digit series will not be noticed at the ambient noise of a normal conversation at a distance of 1m or more in most cases.

The E-M5 is louder than e.g. the Pentax K-3 or K-1, so it is not my preferred choice for situations that require silent cameras.

Best regards,
Michael
 

Doug Kerr

Well-known member
It is interesting to consider the shutter modes in my Panasonic FZ1000 (an integrated zoom lens camera). It offers, via the menu system, the choice of three shutter modes: MSHTR ("mechanical shutter"), ESHTR ("electronic shutter"), and Auto which is said, in the menu "prompt", to choose between the two to get the best result.

The manual has this to say about that:

Mechanical shutter

Description

The camera starts an exposure electronically, and ends it with the mechanical shutter.

Shutter speed

60 to 1/4000th [sec]

Electronic shutter

Description

The camera starts and ends an exposure electronically.

Shutter speed

1 to 1/16000th [sec]

Auto

Depending on the recording condition and the shutter speed, the shutter type is switched automatically.

• Priority is given to the mechanical shutter, which places less limitations on functions, including the ones you use when taking pictures with the flash.

[But recall that the "mechanical" shutter mode is still a hybrid mode, as described above.]

************

All interesting.

I do not know exactly how either of the modes actually works.

The "electronic" shutter mode is, so far as I can tell, absolutely silent.

In the "mechanical" shutter mode, a quite small sound is made. I have been assuming that, as is true for many "compact" cameras, the aperture iris is used as the mechanical shutter.

I have not yet done any reliable testing to see if I can provoke "banding" when shooting under fluorescent lighting.

Best regards,

Doug
 

Doug Kerr

Well-known member
Hi, Robert,

Again my lack of interest in technicalities Doug. I reread and what is being referred to is being able to calculate the light source varying its intensity by the number of bands. Determining example if 60Hz or 50 Hz mains power. So Jim Kasson explains. You would probably enjoy his take on it -

http://blog.kasson.com?p=11258

Thanks so much for that link. That is a very interesting essay.

Best regards,

Doug
 

Doug Kerr

Well-known member
My best understanding of the "fully electronic mode" used in the Panasonic FZ1000 is this:

Before any CMOS sensor can take an exposure, all the sensel photodetectors have to be "charged" to a certain precisely controlled voltage. That is done through an array of gates, one for each photodetector.

After they have been charged, as the exposure takes place, the light falling on each one causes it to discharge. (Yes, I know its usually described the other way, but that's just not how it works.) The amount by which each one has been "discharged" by the end of the exposure tells us the phtometric exposure on it during the exposure (the "sensel photodetector output").

Before those gates "turn loose" of the photodetectors, the photodetectors are essentially "jammed" in their "being charged" condition. Thus, even if light is falling on the sensor, the photo detectors cannot "discharge" - they cannot respond to the light on them.

So in an FZ1000, when we "trip the shutter", the photodetectors are all charged and then quickly "turned loose" (all at once). Thus they begin responding to the light on them during our "exposure".

In the "mechanical" shutter mode, at the end of the exposure time we have set, the mechanical shutter (it is actually the aperture iris) closes. The states of the photodetectors are now "frozen". The state of charge of the photodetectors is then read out, perhaps one row at a time, though gates on the sensor. And this process takes a fair while. But that doesn't hurt.

In the "electronic" shutter mode, the states of the photodetectors are just read out (light still falling on them). So the exposure is finished, "ready or not". And again this process takes a fair while.

So then, don't the photodetectors that are read out last get more exposure than the ones that are read our earlier? Sure, as I have so far described the process. Doesn't that make for a nonuniform "exposure" at different parts of the frame. Well, it would.

But in fact, this is compensated for at the beginning of the exposure. In the "electronic" shutter mode, when the charging paths to the detectors are "turned loose" to allow the photodetectors to begin discharging under the influence of the light falling on them, they are turned loose "row by row" (or however), just as they well be read out at the end of the exposure, and with exactly the same timing.

So for each photodetector, the time from when it is "turned loose" (from the charging circuit) until it is read out will be the same for every photodetector.

You will recognize the great parallel between this and the working of a focal plane shutter.

And so of course we can encounter the same phenomenon, the "skewed" image of moving objects, in the "electronic" shutter mode.

I think.

Best regards,

Doug
 

Doug Kerr

Well-known member
I am very grateful for the completely silent "electronic" shutter mode on my Panasonic FZ1000.

A number of years ago, I was asked to shoot a series of "intimate" chamber music concerts, held at several fine homes in the Dallas area, arranged by a friend we knew from church (the leader of a noted local choral group). I shot the first one with my Canon EOS 300D, but der schauspieldirektor was very cross with me over its rather loud operating sound (SLR mirror and all, of course).

For the next event, I reverted to my Fuji S602, an integrated lens "superzoom" camera, which had a "between the lens" mechanical shutter (the aperture iris, actually), but it still wasn't "silent", and der schauspieldirektor was still pretty irritated.

I have no idea how he had the rest of the series photographed.

Best regards,

Doug
 
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