Is rolling shutter destined to become progressively worse? - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 62 Old 03-22-2016, 04:39 PM - Thread Starter
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Is rolling shutter destined to become progressively worse?

Since CMOS has taken over mainstream camcorders, and I am under the impression that CMOS chips work by sequentially reading an image in pieces rather than taking a whole snapshot like a global shutter/CCD does, will the rolling shutter issue scale progressively as resolution improves?

Considering that 4k is 4x HD, would that make 4k's rolling shutter 4x as bad as rolling shutter on an HD camera?
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post #2 of 62 Old 03-23-2016, 05:26 AM
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Regardless of the severity of rolling shutter in a camera, its manifestation is really dependent on your shooting style. I've owned some of the 'worst' cameras from the standpoint of RS, and you'd be hard pressed to find any evidence of it in any of my videos.

I'm currently shooting with the A6300, considered by some reviews to have the best 4K video quality of any DSLR out there. But it also carries the tag of having some of the worst RS too.

Do I see RS in any of my A6300 videos? Nope. Can I induce it if I so choose? Like virtually any other DSLR I've shot with, sure. However I don't do whip pans and I don't use shooting techniques that would induce it. RS at 24p is worse than RS at 30p. I've always shot at 30p anyway to maximize motion smoothness in 4K, since we currently don't have DSLRs that can shoot 4K @60p .

Even shooting a clip of a moving tiger at the zoo, who was pacing in front of vertical trees, and required me to pan back & forth to capture the action, didn't induce RS.

So for me RS has always been a big yawn. However if you're a fan of whip pans, panning rapidly at telephoto lengths and other such shooting practices, RS could be an issue with many cameras.
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post #3 of 62 Old 03-23-2016, 06:03 AM
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Quote:
Originally Posted by Ken Ross View Post
Regardless of the severity of rolling shutter in a camera, its manifestation is really dependent on your shooting style. I've owned some of the 'worst' cameras from the standpoint of RS, and you'd be hard pressed to find any evidence of it in any of my videos.

I'm currently shooting with the A6300, considered by some reviews to have the best 4K video quality of any DSLR out there. But it also carries the tag of having some of the worst RS too.

Do I see RS in any of my A6300 videos? Nope. Can I induce it if I so choose? Like virtually any other DSLR I've shot with, sure. However I don't do whip pans and I don't use shooting techniques that would induce it. RS at 24p is worse than RS at 30p. I've always shot at 30p anyway to maximize motion smoothness in 4K, since we currently don't have DSLRs that can shoot 4K @60p .

Even shooting a clip of a moving tiger at the zoo, who was pacing in front of vertical trees, and required me to pan back & forth to capture the action, didn't induce RS.

So for me RS has always been a big yawn. However if you're a fan of whip pans, panning rapidly at telephoto lengths and other such shooting practices, RS could be an issue with many cameras.
Just to clarify: The "worst" RS from the A6300 is at frame rates less than 30; accordingly the 4K video quality at 30p is also less than it is at the slower frame rates. I have not seen tests showing the differences, however.
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post #4 of 62 Old 03-23-2016, 08:05 AM
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Originally Posted by markr041 View Post
Just to clarify: The "worst" RS from the A6300 is at frame rates less than 30; accordingly the 4K video quality at 30p is also less than it is at the slower frame rates. I have not seen tests showing the differences, however.
The video quality at 30p is not worse than 24p. Not only have I not seen testing that shows a lesser quality at 30p, but my own testing has shown me there is absolutely no difference. None.

The only difference between the two frame rates, from a visual standpoint, is the wider FOV available from 24p, with the same lens. When I need to capture the widest angle possible with a given lens, I have the option to shoot 24p. The video quality at both 24P & 30p are indistinguishable and equally superb and, IMO, the best I've seen from any consumer/prosumer camera.

I should also note, from the standpoint of my own shooting methodology, my testing at 24p showed no RS either. Again, this is not to say there is no RS, there is, but it's hugely dependent on your own shooting style.
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post #5 of 62 Old 03-23-2016, 08:36 AM
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Originally Posted by Ken Ross View Post
The video quality at 30p is not worse than 24p. Not only have I not seen testing that shows a lesser quality at 30p, but my own testing has shown me there is absolutely no difference. None.

The only difference between the two frame rates, from a visual standpoint, is the wider FOV available from 24p, with the same lens. When I need to capture the widest angle possible with a given lens, I have the option to shoot 24p. The video quality at both 24P & 30p are indistinguishable and equally superb and, IMO, the best I've seen from any consumer/prosumer camera.

I should also note, from the standpoint of my own shooting methodology, my testing at 24p showed no RS either. Again, this is not to say there is no RS, there is, but it's hugely dependent on your own shooting style.
I agree with you that for most competent video shooting RS is a non-issue. The usual "tests" show it is worse than other cameras at <30p, but few would ever use a camera like in those tests.

But, there must be some reason that Sony uses the whole sensor when it can to create 4K video (at the cost of higher RS), and theory says it should be better too compared to crop mode. Why would they use two different modes if they did not have to?

I would like to see a real test; others have reported there is a difference, in noise and resolution. Ken, I know you have a good eye, but this all does not make sense.

Hopefully slashcam.de will test at 24p and 30p. Right now (before testing the a6300), they find the A7r ii has the best 4K resolution for cameras still sold (they have eliminated the NX1, which is still the best). Both the NX1 and the A7r ii sample from the larger pixels, no crop, and they attribute this method as the reason.

https://www.slashcam.de/artikel/Test...a-Kamera-.html
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post #6 of 62 Old 03-23-2016, 09:29 AM
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Originally Posted by markr041 View Post
I agree with you that for most competent video shooting RS is a non-issue. The usual "tests" show it is worse than other cameras at <30p, but few would ever use a camera like in those tests.

But, there must be some reason that Sony uses the whole sensor when it can to create 4K video (at the cost of higher RS), and theory says it should be better too compared to crop mode. Why would they use two different modes if they did not have to?

I would like to see a real test; others have reported there is a difference, in noise and resolution. Ken, I know you have a good eye, but this all does not make sense.

Hopefully slashcam.de will test at 24p and 30p. Right now (before testing the a6300), they find the A7r ii has the best 4K resolution for cameras still sold (they have eliminated the NX1, which is still the best). Both the NX1 and the A7r ii sample from the larger pixels, no crop, and they attribute this method as the reason.

https://www.slashcam.de/artikel/Test...a-Kamera-.html
I have no idea what Slashcam will report in the 30p vs 24p debate, but keep in mind that at 30p, which is where I do almost all my shooting, I'm finding the best overall PQ I've ever shot. So to me the debate is more academic than anything. If somehow 24p 'measured' better, that's fine too, many will be delighted with the 24p results and, as I've said, folks who shoot like you and I will find no real issue with RS. BTW, there's little question in my mind that the A6300 will outscore the A7RII in resolution. Having both, that's what I'm seeing in real world use. I think many reviews have already hinted at that. I've seen many state what I've said, the A6300 has the best video out there.

Of course any real-world testing done with the same lens, will have to compensate for the difference in FOV to see any real differences.

Mark, let's put it this way, if there is a difference it's too small for me to see in real-world shooting. To me that's where the 'rubber meets the road'. I can't get lost in the minutia. So whatever is found, in real world use, I'm simply not seeing it. Both frame rates are superb. In my case I've never been a real fan of 24p and would it use it only for the widest of WA shooting. My objection to lower frame rates is a reduction in motion smoothness. Of course the nice thing about using 24p in the A6300, is that it does give you a wider FOV, and thus motion issues are harder to spot.

I'm also finding the low light performance, as many reviews have suggested, is truly excellent and somewhat unexpected.

Edit: One thing I forgot to mention is that from what I've read, Sony uses a very different approach in sampling the sensor in the A6300 and this is why its video quality is better. I haven't read the nitty gritty as to what's done, just that it is different. I should also note that in the A7RII, video quality is actually better in the cropped APSC mode. Tests have shown that to be the case and as I used the A7RII, I found that to be true. So it's quite possible that the 30p mode of the A6300 may actually 'test out' to have the better video quality.

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post #7 of 62 Old 03-23-2016, 09:44 AM
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Quote:
Originally Posted by Ken Ross View Post
Do I see RS in any of my A6300 videos? Nope.
Says more about your shooting style than the camera. The question was about cameras.
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post #8 of 62 Old 03-23-2016, 10:08 AM
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Originally Posted by Ungermann View Post
Says more about your shooting style than the camera. The question was about cameras.
...and the answer is "no, unless you make it an issue".

Shooting like you're high on caffeine is bad practice regardless of the shutter type.
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post #9 of 62 Old 03-23-2016, 10:13 AM
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Says more about your shooting style than the camera. The question was about cameras.
You can't give advice without also indicating how shooting style impacts a camera 'issue'. That issue may or may not be a real world problem.
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post #10 of 62 Old 03-23-2016, 11:11 AM
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You can't give advice without also indicating how shooting style impacts a camera 'issue'. That issue may or may not be a real world problem.
The question was quite simple: considering that rolling shutter means sequential line scanning, does increasing number of lines and number of elements in each line increase the time of the scanning, thereby increasing rolling shutter effects. There is nothing about shooting style or real world problems in the question.

I consider it an interesting topic worth researching, and on the face of it, this seems to be a legitimate concern. On the other hand, the electronics is getting quicker, so maybe the increased scanning speed compensates increased number of lines to scan.

The revised questions would be:

* whether the time needed to scan of a single frame took a dive since introduction of 4K cameras;
* whether the situation is improving;
* whether the current generation of 4K cameras are better or worse than the latest generation of HD cameras.

These questions cannot be answered by talking. They can be answered with numbers.

If you want to talk shooting style and real-world situations, then some benchmarks should be established by knowledgeable people. The benchmarks would identify shooting situations and the acceptable speed of frame/line scanning for each situation. The manufacturers would provide the numbers for their cameras. Then a consumer would compare his expected shooting situations with the numbers from the experts and the numbers from the particular camera and make an educated choice.

Last edited by Ungermann; 03-23-2016 at 11:17 AM.
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post #11 of 62 Old 03-23-2016, 11:54 AM
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Quote:
Originally Posted by Ungermann View Post
The question was quite simple: considering that rolling shutter means sequential line scanning, does increasing number of lines and number of elements in each line increase the time of the scanning, thereby increasing rolling shutter effects. There is nothing about shooting style or real world problems in the question.

I consider it an interesting topic worth researching, and on the face of it, this seems to be a legitimate concern. On the other hand, the electronics is getting quicker, so maybe the increased scanning speed compensates increased number of lines to scan.

The revised questions would be:

* whether the time needed to scan of a single frame took a dive since introduction of 4K cameras;
* whether the situation is improving;
* whether the current generation of 4K cameras are better or worse than the latest generation of HD cameras.

These questions cannot be answered by talking. They can be answered with numbers.

If you want to talk shooting style and real-world situations, then some benchmarks should be established by knowledgeable people. The benchmarks would identify shooting situations and the acceptable speed of frame/line scanning for each situation. The manufacturers would provide the numbers for their cameras. Then a consumer would compare his expected shooting situations with the numbers from the experts and the numbers from the particular camera and make an educated choice.
The answer is: it shouldn't make a difference what the resolution of the camera is.

30 frames per second is still 30 frames per second regardless of resolution. The whole sensor will be scanned once every 30 seconds. The extra resolution doesn't add any time to that.

The only thing you get is fewer jagged edges when that light pole wiggling back and forth in the frame is bending like a snake. The rolling shutter effect is no better or worse than other resolutions at the same frame rate.

The case that could be made is that with 4K, we don't normally have the option of 60fps or higher to more easily avoid the issue. The higher the frame rate, the fewer changes that can happen during the scanning process each frame.

Since we're unlikely to see global shutters in most cameras most of us can afford, the only hope for combating the issue is to see progress in getting higher frame rates with the higher resolution cameras. Faster processors with faster memory that can run cooler are the only way we'll see that, though.

As far as real world situations, as a professional, I can tell you that flicking a camera quickly back and forth across an object is not going to produce usable video with any camera or sensor setup. However, in an active ENG situation where things are unfolding dynamically around you, rolling shutter effects are the last thing anyone will care about. For anything else, real world good shooting practice means panning slowly and smoothly to avoid making your viewer motion sick.

Last edited by NetworkTV; 03-23-2016 at 11:58 AM.
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post #12 of 62 Old 03-23-2016, 12:16 PM
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Originally Posted by NetworkTV View Post
The answer is: it shouldn't make a difference what the resolution of the camera is.
30 frames per second is still 30 frames per second regardless of resolution. The whole sensor will be scanned once every 30 seconds. The extra resolution doesn't add any time to that.
Not as simple. The sensor needs to complete acquisition of a single frame within 1/30 of a second, but the time can be shorter. Say, 9/300 spent exposing the sensor, and 1/300 spent collecting the charges. Or spend 99/3000 exposing the sensor and 1/3000 collecting the charges. Also, whether charges are collected line by line or in batches. Funny, how CMOS sensors are closer in their behavior to vacuum pickup tubes than CCD.
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As far as real world situations, as a professional, I can tell you that flicking a camera quickly back and forth across an object is not going to produce usable video with any camera or sensor setup. However, in an active ENG situation where things are unfolding dynamically around you, rolling shutter effects are the last thing anyone will care about. For anything else, real world good shooting practice means panning slowly and smoothly to avoid making your viewer motion sick.
Shakycam caused by flicking the camera is different from vomit-inducing jello effects. And don't tell me you never shoot trains, buses, helicopters, spinning coins... Well, maybe you do not shoot spinning coins. In an active ENG situation even crappy smartphone video works, but I would watch it only if this is the only source of important information, like a cop beating an innocent guy.

P.S. Panasonic claimed rolling shutter was not a problem, yet recommened panning in a certain direction to reduce skew.
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Originally Posted by premiumcapture View Post
Since CMOS has taken over mainstream camcorders, and I am under the impression that CMOS chips work by sequentially reading an image in pieces rather than taking a whole snapshot like a global shutter/CCD does, will the rolling shutter issue scale progressively as resolution improves?

Considering that 4k is 4x HD, would that make 4k's rolling shutter 4x as bad as rolling shutter on an HD camera?
Just for clarity,
There are CCD sensors with rolling shutters as well as CMOS with global shutter.

For example, Ive had the Blackmagic CMOS 4K and the Digital Bolex CCD s16, both featuring a global shutter.
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post #14 of 62 Old 03-23-2016, 01:17 PM
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The answer is: it shouldn't make a difference what the resolution of the camera is.

30 frames per second is still 30 frames per second regardless of resolution. The whole sensor will be scanned once every 30 seconds. The extra resolution doesn't add any time to that.

The only thing you get is fewer jagged edges when that light pole wiggling back and forth in the frame is bending like a snake. The rolling shutter effect is no better or worse than other resolutions at the same frame rate.

The case that could be made is that with 4K, we don't normally have the option of 60fps or higher to more easily avoid the issue. The higher the frame rate, the fewer changes that can happen during the scanning process each frame.

Since we're unlikely to see global shutters in most cameras most of us can afford, the only hope for combating the issue is to see progress in getting higher frame rates with the higher resolution cameras. Faster processors with faster memory that can run cooler are the only way we'll see that, though.

As far as real world situations, as a professional, I can tell you that flicking a camera quickly back and forth across an object is not going to produce usable video with any camera or sensor setup. However, in an active ENG situation where things are unfolding dynamically around you, rolling shutter effects are the last thing anyone will care about. For anything else, real world good shooting practice means panning slowly and smoothly to avoid making your viewer motion sick.
Precisely. That's why a discussion without referencing one's shooting style, is pure folly. What could be a huge issue for one shooter (who insists on making his viewers nauseous) may be a total non-issue for those that shoot in a more professional manner.

I've yet to see RS an issue on any camera I've ever used...despite the insane whip pans that you see on YouTube to 'prove' a camera has RS issues.
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post #15 of 62 Old 03-23-2016, 02:45 PM
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That's why a discussion without referencing one's shooting style, is pure folly.
Why do you want to discuss shooting style when it was not in the question: "Will the rolling shutter issue scale progressively as resolution improves?"

To me this is similar to discussing story, acting, framing, editing, color-timing when answering a question about choice between say a 4K or HD camera. You praise every new technical improvement in resolution and DR while seemingly disregarding non-technical parts of a video. Yet in this case you bring non-technical points front and center while the question was pure technical.

I guess you motto can be phrased as "Give me resolution no matter whether it stutters, has skew, exhibits jello, or is just a bad story".
My motto would be "Story first, good camera moves second, absolutely no jello, and I don't care much about resolution or frame rate as long as I don't see interlacing".
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Originally Posted by Ungermann View Post
Why do you want to discuss shooting style when it was not in the question: "Will the rolling shutter issue scale progressively as resolution improves?"

To me this is similar to discussing story, acting, framing, editing, color-timing when answering a question about choice between say a 4K or HD camera. You praise every new technical improvement in resolution and DR while seemingly disregarding non-technical parts of a video. Yet in this case you bring non-technical points front and center while the question was pure technical.

I guess you motto can be phrased as "Give me resolution no matter whether it stutters, has skew, exhibits jello, or is just a bad story".
My motto would be "Story first, good camera moves second, absolutely no jello, and I don't care much about resolution or frame rate as long as I don't see interlacing".
Ungermann, I think NetworkTV covered the area that's apparently of the greatest concern to you. His take that resolution would not impact RS sounded correct and to the point. So no need to rehash that.

Second, I made a point of shooting style because unlike resolution, color & DR that affects ALL shooting styles, RS only impacts certain shooting styles. So I stick by what I said. If you're a fan of whip pans and such, so be it.

Lastly, of course I'd be negatively impacted by stuttering, jello and such. That's why I learn how to avoid it if my equipment has the potential to manifest it.

If I were to be as sarcastic as you (and I've always given you a Phd in that arena ), I could easily say that your motto would be "I don't care if my camera produces a blurry mess with monolithic colors, as long as I have the right camera moves and story."

Enough, this is getting silly.
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I made a point of shooting style because unlike resolution, color & DR that affects ALL shooting styles, RS only impacts certain shooting styles.
This makes sense.
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I could easily say that your motto would be "I don't care if my camera produces a blurry mess with monolithic colors, as long as I have the right camera moves and story."
As long as I can figure out what is happening, by all means the story is paramount.
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Enough, this is getting silly.
You are free to remove yourself from the discussion at any time.
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post #18 of 62 Old 03-23-2016, 07:53 PM
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To answer the OP's questions: Not necessarily. It all depends on two key factors (not counting global shutter), the number of sensor pixels the camera has to read and the performance of the IP and/or sensor bandwidth to keep up with the increasing number of pixels that have to be read by the camera.

The evidence is very clear. The cameras that have the best resistance to or least rolling shutter artifacts tend to be cameras that are equipped with video-dedicated sensors, not hybrid stills/video that usually have very high pixel count in relation to the the required number of pixels to form the image of the videos. Take the Sony A6300 for example, the sensor has 24M pixels but the 4K UHD image only requires about 8M pixels per frame regardless of the format used.

Now I have the list of video cameras that have the best rolling shutter resistance though I don't have the exact mili-second numbers with me at the moment but you could google for them. Listing not necessarily in the order of performance but cost**.

- Arri Alexa/Ameira
- Sony FS7
- Sony FS5
- Sony AX40/53/55

**There certainly are a few cameras that could be included in the list but only because I have not seen their performance numbers yet. As you can see the cameras above vary greatly in prices and uses but all have one thing in common. Low pixel count. The Alexa/Ameira I believe have about 10M pixels, the Sony FS5 and FS7 have around 11M pixels and the consumer palmcorder Sony AX40/53/55 have only 8M pixels.

Other mage quality issues aside, the lower number of pixels to be scanned or read by the camera, coupled with the advancement in the cameras' data pipeline and the IP, the better rolling shutter performance. Faster readout time, less chance of subjects' positional displacement, because of less data to deal with.
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post #19 of 62 Old 03-23-2016, 11:55 PM
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Here are some test figure rom a fellow on dvxuser. He is happy to receive test data from other camera models if you have one that's not on the list.
http://www.dvxuser.com/V6/showthread...-on-this-issue!


NX1 1080p -------- 7.9 ms (7.7-8.0-8.1-7.8)
a7r II 1080p S35- 10.5 ms (11.0-10.0)
BMMCC ----------- 13.4 ms (13.7-13.5-12.9)
GH4 1080p ------- 13.7 ms (13.7-13.5-13.1-14.0-13.9-13.5-13.5-13.9)
D750 ------------ 14.5 ms (14.6-14.1-14.6-14.8)
RX10 ------------ 14.8 ms (14.5-14.8-15.0)
a6300 1080p24 --- 15.2 ms (15.8-14.6)
GH3 ------------- 15.5 ms (15.4-15.7-15.4)
RX100 IV 1080p -- 16.9 ms (16.5-17.3) (without stabilization it's slightly faster: 16.1)
BMPCC ----------- 17.8 ms (17.7-17.7-20.0-20.0)
a7s APS-C 1080p - 19.5 ms (20.3-18.4-19.5-19.5)
a7R II 4K FF ---- 19.9 ms (19.3-19.6-19.4-21.2)
5D3 ------------- 20.5 ms (20.7-20.5-20.4)
D5200 ----------- 22.4 ms (22.5-22.1-22.6)
GH4 4K/UHD ------ 22.5 ms (23.2-22.3-22.7-22.7-22.4-21.8-22.4-22.8-22.6)
BMC ------------- 25.0 ms (26.7-24.8-23.5)
5D2 ------------- 25.9 ms (25.5-26.4-25.8)
5Dsr ------------ 27.7 ms (27.5-27.9-27.6)
NEX-5N ---------- 29.4 ms (28.8-29.6-28.9-29.8-29.8-29.1-29.7)
a7s II FF 1080p - 30.3 ms (29.5-31.2)
a7s II FF 4K ---- 30.4 ms (30.2-30.6)
a7s FF 1080p ---- 30.5 ms (30.1-32.0-30.5-30.3-29.2-30.9)
NX1 4K ---------- 30.9 ms (30.6-31.6-31.4-30.7-30.2)
NX1 UHD --------- 32.6 ms (32.9-32.0-32.9-32.5)
a7R II 4K S35 --- 33.3 ms (35.6-32.2-32.8-35.3-32.6-31.1)
RX100 IV 4K ----- 36.6 ms (36.4-36.7) (without stabilization it's slightly faster: 35.7)
a6300 4K 24fps -- 39.0 ms
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post #20 of 62 Old 03-24-2016, 01:52 AM
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Rolling shutter cannot exceed the following:
24p: 41.6ms
30p: 33.3ms
60p: 16.7ms
120p: 8.3ms

Because that is how much time you have until the next frame has to be read.
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post #21 of 62 Old 03-24-2016, 05:15 AM
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Quote:
Originally Posted by Tugela View Post
Rolling shutter cannot exceed the following:
24p: 41.6ms
30p: 33.3ms
60p: 16.7ms
120p: 8.3ms

Because that is how much time you have until the next frame has to be read.
Tug, then that guy's chart is wrong since the RX100 IV exceeds the 33.3ms for 30p.

It's funny, I was never even aware that RS was considered an issue for that camera.

An interesting observation one could make, is that there seems to be a correlation between those cameras with the generally recognized best PQ and a high degree of RS.
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post #22 of 62 Old 03-24-2016, 06:49 AM
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Noticeable skewing of vertical lines in too fast panning shots along with wobbles or jelloes often stick out like a sore thumb when the videos are watched by non-techie viewers. While they could understand why a few frames are not really in focus or some shots are shaky and not others, or some too bright/dark. These skews and jelloes, in my experience, would almost invariably elicit something like: "Why the hell are those poles leaning like that?" or "What are those darn ripples?" No surprise they ask since these things simply look unnatural. Outside the realm of CMOS based videos, they just don't exist.

For our private videos I think it's OK. We all know what they are and why they happen. If we can't tolerate them then we know what we can't do when we go out shooting. But if the videos are to be seen by our clients, our clients' viewers, or any audience whom we try to sell something to through the videos they watch, these imaging anomalies in one way or another have to be suppressed at least to the point of being unnoticeable to normal viewers. Or better, eliminate them by using global shutter, CCD cameras or just forget about including fast moving shots in your videos.

Despite some downsides such as lower sensitivity, a global shutter is put in a number of cameras, all for professional use, for a reason.
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post #23 of 62 Old 03-24-2016, 07:10 AM
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Those same professional cameras are capable of shooting [email protected], so fast pans (if so desired) become more practical. Even without RS, fast pans in 24p/30p just aren't as pleasant to watch as when done at 60p.
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post #24 of 62 Old 03-24-2016, 07:50 AM
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I suspect the answer to the original question, for the near future at least, is that rolling shutter effects will be kept just about small enough that manufacturers think they can get away with it and still sell the camera.

Quote:
Originally Posted by Ken Ross View Post
Tug, then that guy's chart is wrong since the RX100 IV exceeds the 33.3ms for 30p.
What's actually measured is the ratio of rolling shutter time to time between frames, so the guy either made a bad measurement or was told or assumed the wrong frame rate.

Not only do the RS effects tend to increase with the number of sensels to be scanned, but for the end user they also increase with focal length used. I can understand why people who rarely venture beyond about 100mm focal length should be unconcerned with rolling shutter, but as you go further, jello/wobble can destroy a shot merely when a gust of wind shakes a stationary camera and tripod, particularly at lower shutter speeds such as would be used in low-light situations.
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post #25 of 62 Old 03-24-2016, 11:10 AM
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Quote:
Originally Posted by Mattias Burling
Here are some test figure rom a fellow on dvxuser.
Thanks. Whatever formula he uses, it clearly shows that RS in 4K is worse than in HD.
Quote:
Originally Posted by P&Struefan
Noticeable skewing of vertical lines in too fast panning shots along with wobbles or jelloes often stick out like a sore thumb when the videos are watched by non-techie viewers.
These defects stick out like a sore thumb for techie viewers as well. I can live with some skewing, but cannot stand jello. When I see a movie with fancy shots, color correction, shallow DOF... and then - bam! - jello, I cringe. So much money spent, but a technical defect ruins the movie for me.
Quote:
Originally Posted by P&Struefan
For our private videos I think it's OK.
Not OK for me.
Quote:
Originally Posted by P&Struefan
Or better, eliminate them by using global shutter, CCD cameras or just forget about including fast moving shots in your videos.
This is one of the reasons I bought the HDC-SD9 off eBay: 3CCD + FullHD + native 24p = modern-day Super8. Does not have a pistol-style grip though.
Quote:
Originally Posted by Cloudstrewn
I can understand why people who rarely venture beyond about 100mm focal length should be unconcerned with rolling shutter, but as you go further, jello/wobble can destroy a shot merely when a gust of wind shakes a stationary camera and tripod, particularly at lower shutter speeds such as would be used in low-light situations.
I concur!
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post #26 of 62 Old 03-24-2016, 11:22 AM
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Quote:
Originally Posted by P&Struefan View Post
Noticeable skewing of vertical lines in too fast panning shots along with wobbles or jelloes often stick out like a sore thumb when the videos are watched by non-techie viewers. While they could understand why a few frames are not really in focus or some shots are shaky and not others, or some too bright/dark. These skews and jelloes, in my experience, would almost invariably elicit something like: "Why the hell are those poles leaning like that?" or "What are those darn ripples?" No surprise they ask since these things simply look unnatural. Outside the realm of CMOS based videos, they just don't exist.

For our private videos I think it's OK. We all know what they are and why they happen. If we can't tolerate them then we know what we can't do when we go out shooting. But if the videos are to be seen by our clients, our clients' viewers, or any audience whom we try to sell something to through the videos they watch, these imaging anomalies in one way or another have to be suppressed at least to the point of being unnoticeable to normal viewers. Or better, eliminate them by using global shutter, CCD cameras or just forget about including fast moving shots in your videos.

Despite some downsides such as lower sensitivity, a global shutter is put in a number of cameras, all for professional use, for a reason.
Actually, the "bending" effect does exist outside of rolling shutter, as anyone who wears glasses and gets a new prescription will be well aware. If you rotate your head rapidly, straight lines in your peripheral vision bend. After you have been wearing the new glasses for a while your brain corrects for the distortion and you don't notice it any more, but for those first few weeks it is very noticeable and disorientating.

The same thing happens in a camera (particularly at wider angles) when the focus plane rotates.
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post #27 of 62 Old 03-24-2016, 11:36 AM
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Quote:
Originally Posted by Ken Ross View Post
Tug, then that guy's chart is wrong since the RX100 IV exceeds the 33.3ms for 30p.

It's funny, I was never even aware that RS was considered an issue for that camera.

An interesting observation one could make, is that there seems to be a correlation between those cameras with the generally recognized best PQ and a high degree of RS.
The other point to note is that for a particular camera the upper maximum for rolling shutter should be determined by it's highest frame rate for a particular resolution. So, if your camera can shoot 1080p at 120 fps, rolling shutter should be less than 8.3 ms for all lower frame rates as well, unless there is a processor bottleneck caused by higher quality settings.

In any event, the frame rate sets a hard cap for rolling shutter. Any number that comes out higher in a test is evidence that the testing methodology is flawed.
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post #28 of 62 Old 03-24-2016, 12:05 PM
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Quote:
Originally Posted by Cloudstrewn View Post
I suspect the answer to the original question, for the near future at least, is that rolling shutter effects will be kept just about small enough that manufacturers think they can get away with it and still sell the camera.



What's actually measured is the ratio of rolling shutter time to time between frames, so the guy either made a bad measurement or was told or assumed the wrong frame rate.

Not only do the RS effects tend to increase with the number of sensels to be scanned, but for the end user they also increase with focal length used. I can understand why people who rarely venture beyond about 100mm focal length should be unconcerned with rolling shutter, but as you go further, jello/wobble can destroy a shot merely when a gust of wind shakes a stationary camera and tripod, particularly at lower shutter speeds such as would be used in low-light situations.
And yet in my 4K zoo video, as I was at a focal length I'd estimate to be about 300mm, I was able to pan back & forth, following a tiger as he walked in front of vertical trees, and yet I saw no jello or evidence of RS in those trees. IMO it's very easy to avoid RS artifacts.

I would certainly never shy away from 4K or return to HD for that reason. Once you've seen 4K on a UHD TV, it's very hard to go back to HD. 4K not only improves resolution, but also improves on color.
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post #29 of 62 Old 03-24-2016, 12:40 PM
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Quote:
Originally Posted by Ken Ross View Post
And yet in my 4K zoo video, as I was at a focal length I'd estimate to be about 300mm, I was able to pan back & forth, following a tiger as he walked in front of vertical trees, and yet I saw no jello or evidence of RS in those trees. IMO it's very easy to avoid RS artifacts.
I think you misunderstood the post you quoted. Take your 300mm, put it on a tripod, do not pan, just bump the tripod or set it in a moderately strong wind. Not so stable anymore..
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post #30 of 62 Old 03-24-2016, 12:50 PM
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Quote:
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IMO it's very easy to avoid RS artifacts.
Try using a telephoto and tripod when there's a wind or other agent which can knock them...
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