July 26, 2014

Rolling Shutter: How Does the Sony a7S Compare to Everything Else?

Earlier in the week, we shared a comparison of the dynamic range of the Sony a7S to a few other popular cameras, and the results were enlightening. It turns out that the combination of the massive pixels of the a7S sensor and the ability to shoot with an S-log2 gamma curve provides for some impressive dynamic range, to say the very least. Of course, we all know that no camera system is perfect, and the a7S is no exception, especially in regards to rolling shutter. In another comparative test from Cinema5D, they measured the effects of rolling shutter on a variety of popular CMOS cameras, and unfortunately, our beloved a7S didn't fare well at all.

First, here's a brief rundown of how the rolling shutter test was conducted:

rs_grab

On the left you can see a frame grab from the A7S video file used to determine its rolling shutter. We used a rotating test chart framed identically with all cameras. The amount of horizontal offset between the first and last line of pixels determines the severity of rolling shutter which we measured in milliseconds. These are approximate values (Precision is limited by our method of testing as it involves a slight amount of motion blur).

And here are the results from the Cinema5D rolling shutter test:

A7s Rolling Shutter Test

This is what the Cinema5D folks had to say about the results:

Our test results show that the A7S’ rolling shutter in full frame HD mode is severe, but we also found that the Canon 1D C performs similarly in 4K mode. Among DSLR style cameras in our test the GH4 in 4K mode performed best and is more or less on par with the A7S’ crop mode, and the 5D mark III coming in right behind that. As expected the ARRI AMIRA has an outstanding shutter readout speed almost looking like a global shutter.

Essentially, this test shows that the a7S is, in fact, highly susceptible to rolling shutter, especially when shooting in full frame mode -- which, let's face it -- is how most people use the camera. It's rather unfortunate considering that the camera exceeds expectations in many other areas like dynamic range and low-light ability. But again, there is no perfect camera.

Here's a quick example of the rolling shutter on the a7S, both before and after a "rolling shutter repair" effect has been applied:

Ultimately, the fact that the a7S suffers from severe rolling shutter isn't something that should necessarily deter anybody from using the camera, except in very specific situations such as frenetic handheld work and when objects need to move quickly through frame. Rolling shutter is something that most of us who have been shooting with DSLRs and non-global shutter cameras are accustomed to dealing with, and there are numerous workarounds, both in how you shoot and how you post-process the footage, that can alleviate some of nasty effects of rolling shutter.

Link: Rolling Shutter - A7s vs. the Others -- Cinema5D

Your Comment

56 Comments

I think it's a bit of a stretch to say full frame is how most people will use it. I just go one of these and I doubt I'll be going full frame with it all the time. Some of my lenses areng useable in full frame and sometimes I need the extra focal length the crop will give me. Also in a situation where rolling shutter might be an issue I'll likely chose to shoot cropped, where the rolling shutter is much more mitigated. Full frame is a bit overkill in many situations as it is significantly larger than a standard 35mm mp film frame.

July 26, 2014 at 4:28PM, Edited September 4, 11:56AM

0
Reply
Bill Streeter

I agree. I don't plan on using it in full frame mode when I get one. I've been using a 7d for a few years now so I'm accustomed to crop frame. Plus the rolling shutter repair did wonders for the footage. Not really a deal breaker for me.

July 29, 2014 at 5:50PM, Edited September 4, 11:56AM

0
Reply

Anyone buying an A7 should not be concerned about rolling shutter.
The A7 is essentially a still camera with video capabilities.
Sony (and other manufacturers) makes very good video cameras including the 4k VG100 in the same price range as the A7.
Why would you buy a still camera to shoot video when a better video camera exists in the same price range and does not have the limitations of a still camera used to shoot video.

August 3, 2014 at 12:20AM, Edited September 4, 11:56AM

0
Reply
Wayne

Post have showed great results in treating rolling shutter, I am sorry just still blown with the low light capabilities :)

July 26, 2014 at 4:37PM, Edited September 4, 11:56AM

0
Reply
David S.

"You forgot to say 'away' again..."

July 28, 2014 at 1:30PM, Edited September 4, 11:56AM

0
Reply
Ty

So if you have shot with a 1DC you know how to deal with it...it's honestly not as bad as people think. I've shot running shoulder rig action shots with the 1DC and it wasn't bad, it's mainly "handheld" work that amateurs do which you shouldn't be doing in the first place as stabilization is one of the key fundamentals. You should never have the fix it in post attitude or your work will suffer.

What other camera does the most for the price? the A7s is hard to beat. At the end of the day although 8-bit, the image is nice, especially for HD. The range is unheard of in a DSLR and you get full frame and 1080 slo mo as well as unbeatable low light.

As for people saying the range is all in the shadows. Why is that a bad thing? If you have more range in the shadows you don't have to expose as high in the highlights and you end up with correct exposure regardless. Think about it...

July 26, 2014 at 4:40PM, Edited September 4, 11:56AM

0
Reply
Brad Watts

Thanks for this! Great work.

Just in the interest of science, it might be worth having someone double-check the results. My own tests (which you can find on my YouTube channel, in my GH4 review), and those of someone else (whom I no longer remember), found the GH4 in 4k mode to have significantly worse rolling shutter than the 5D3, and I even recall seeing someone from Panasonic discussing the challenge of offloading 4k data from the sensor as fast as possible. The GH4 had less rolling shutter than the 5D3 in 1080p mode, however.

We do most of our filming with the GH4 in 4k mode, and subjectively, the rolling shutter seems just awful. Anyway, I thought maybe your result was for the GH4 in 1080p mode rather than 4k. Either way, I'd be curious to see how it tests in 1080p.

July 26, 2014 at 4:41PM, Edited September 4, 11:56AM

0
Reply

In my own tests of the GH4 , I found that FHD is around 13msec (I measured 1/76 sec difference from top of frame to bottom), while 4K is 1/46 sec or about 22 msec. So I'm in agreement with you, Tony. I'm guessing that "4K" on the GH4 test is a typo, like "a chart develpoped by Cinema5D"!

July 28, 2014 at 2:58PM, Edited September 4, 11:56AM

0
Reply

it boggles my mind that the industry EVER accepted this "feature" in the first place. while nobody lives and dies by a whip-pan. having things turn to noodles when it does suit the scene is utterly ridiculous.

i just dont understand why moire is bad, aliasing is bad. banding is bad, but somehow, slanted light posts and psychedelic looking fans and properllers are just fine?

July 26, 2014 at 5:26PM, Edited September 4, 11:56AM

0
Reply
wayne

How did they do that rolling shutter repair?

July 26, 2014 at 5:30PM, Edited September 4, 11:56AM

4
Reply
Brian

I'd guess it was warp stablizer in AE/PP. Under the advanced section it has an option to fix rolling shutter. Idk, I've never used it so I could be wrong.

July 26, 2014 at 5:41PM, Edited September 4, 11:56AM

0
Reply
alex

No. There's a "Rolling Shutter Repair" effect in Premiere Pro.

July 27, 2014 at 4:08PM, Edited September 4, 11:56AM

0
Reply
Leo

Here is a link to lots of different rolling shutter measurements done by a guy named Samuel H. He's spent a lot of time conducting these tests over the last little while, and his process seems pretty reliable, and his results for various cameras have been corroborated by other testers. I think I would trust his numbers a little more than Cinema5D, though both sources seem to rate the cameras similarly in relation to one another.

GH4 1080p mode: 13.7 ms
A7s APS-C mode: 19.5 ms
GH4 4K: 22.5 ms
A7s full frame: 30.5 ms

The Epic is at 16 so the A7s is still pretty close in APS-C mode, which is still fantastic with resolution and dynamic range. But it doesn't tough the GH4 in terms of readout.

http://www.dvxuser.com/V6/showthread.php?303559-Measuring-rolling-shutte...!

July 26, 2014 at 5:39PM, Edited September 4, 11:56AM

0
Reply
Kenneth Merrill

Samuel H' s numbers seem more accurate to me,

July 26, 2014 at 6:55PM, Edited September 4, 11:56AM

1
Reply
Ebrahim Saadawi

This is also an interesting link, showing that the resolution remains nearly the same in APS-C mode, and it also keeps the moire and aliasing to a negligible minimum through 60p (much better than the moire you see in FF at 60p).

120p, on the other hand, looks pretty fuzzy and moire-ridden no matter what--something that keeps me interested in the GH4 (besides the faster sensor readout).

July 26, 2014 at 7:30PM, Edited September 4, 11:56AM

0
Reply
Kenneth Merrill

July 26, 2014 at 7:40PM, Edited September 4, 11:56AM

0
Reply
Kenneth Merrill

...
Public don't care about rolling shutters... They (we) want some good stories... nice actors... and nice light...
...
I really don't understand this...
...

July 26, 2014 at 7:28PM, Edited September 4, 11:56AM

0
Reply
João Marco

Every part of the image affects the way the story is received. Sure, a masterful story may survive terrible set design, rough CG, bad lighting, and even jello-cam--but a "pretty good" story won't. Every part of an image that looks weird or not quite right is a distraction, and you don't want people to be distracted from your nice actors do you?

July 26, 2014 at 7:33PM, Edited September 4, 11:56AM

0
Reply
Kenneth Merrill

I think his point is that there are filmmakers and then there are gear heads. People whining about rolling shutters are usually the latter. It's something you really only notice in jerking the camera back and forth and no one shoots like that anyway. Yes propellers may look funky but if you're not shooting propellers the point is mute. Nitpicking a camera that is at such a low price point for amazing features is ridiculous. I've never understood the rolling shutter problem either because honestly it's never been a noticeable problem in any video I've ever shot.

July 26, 2014 at 7:47PM, Edited September 4, 11:56AM

0
Reply
stephen

"any video you've ever shot" being the operative term...

I'll fully admit I'm a gear head; I love tech and gear and comparing cameras and stuff. It's just fun :)

That doesn't mean I don't shoot stuff, and I always try to choose the best tool for the job. My style involves a lot of handheld and fast-movement stuff (not really whip-pans, though), and I've even been bothered by the RS on cameras like the C100 that are rated at 16ms. For me it's a big deal--maybe not for others, but for me. Philip Bloom, for instance seems to have no problem with it because most of his shots are grounded and super steady.

Don't generalize based on your own limited experience.

July 26, 2014 at 8:31PM, Edited September 4, 11:56AM

0
Reply
Kenneth Merrill

I shoot every day and I think this is an important test. I would not take a low performing rolling shutter camera on a car shoot, sports shoot or action hand held. I shoot with the ALEXA also, and the lack of jelly is beautiful really. A pan is a pan, humans look like humans the whole way. I shoot with the C300 also and it performs very well, a nice middle ground between the high end cinema cams and dslrs. It's a shame that with all the processing power of the A7 they couldn't get a faster readout, I guess that's the price you pay for extreme low light.

July 27, 2014 at 12:03AM, Edited September 4, 11:56AM

0
Reply

If Claire is your real name, and if you are as female as that name implies, then I am so happy to see you here. I think websites like this and the industry at large are severely lacking women's influence.

July 27, 2014 at 12:45AM, Edited September 4, 11:56AM

0
Reply
Kenneth Merrill

Or, it could be a man with a really unfortunate name.

July 27, 2014 at 3:06AM, Edited September 4, 11:56AM

0
Reply
Vox

...or you could just check out HER website and get rid of any mysteries...;)

July 27, 2014 at 4:46AM, Edited September 4, 11:56AM

0
Reply
mariano

Hahaha that would be awesome.. but alas no. It is a girl ;)

July 28, 2014 at 9:40AM, Edited September 4, 11:56AM

0
Reply

...what are you talking about..?

July 27, 2014 at 10:05AM, Edited September 4, 11:56AM

0
Reply
Erica

...what are you talking about..?

July 27, 2014 at 10:05AM, Edited September 4, 11:56AM

0
Reply
Erica

Yeah I do wonder how much sensitivity they are gonna start to get out of their next gen CCD's. I'd also like to see someone recreate these tests from the article about Canon's low light monster sensor from a while back: http://nofilmschool.com/2013/03/canon-full-frame-35mm-cmos-sensor-see-dark/

July 27, 2014 at 1:37PM, Edited September 4, 11:56AM

0
Reply

Oh god.......really?

Yes, we have heard this before........story, actors bla bla bla. It's all relevant, even the image from the camera. There are plenty of stories here on scripting, story boarding etc etc. This one is about the camera.

July 27, 2014 at 1:04AM, Edited September 4, 11:56AM

0
Reply
Tone13

I'm just dinking around, doing daily internet reading and there's my rolling shutter video. Random.

July 26, 2014 at 7:32PM, Edited September 4, 11:56AM

0
Reply
Leo

Rolling shutter to me is a non issue because even on cams with bad rolling shutter A) you rarely see it because most aren't throwing the camera about like that all the time and B) follow the 180 degree rule and its often not visible with the motion blur anyhow.

I remember when Sony were pushing the F55 with its global shutter they used helicopter rotor blades as an example of why you need global shutter. Well no DP is going to want to shoot rotors with a high shutter speed. You'd want beautiful motion blur of those rotors and following the 180 degree rule a helicopter rotor shot will look the same rolling shutter or no rolling shutter.

A much more powerful feature to have is the great dynamic range this camera has because that IS IN EVERY SHOT...

July 26, 2014 at 8:15PM, Edited September 4, 11:56AM

0
Reply

Yeah that's be big selling point for me. I would pretty much always shoot in APS-C mode anyway, and the RS isn't bad there. That dynamic range is awesome though, and the roll-off is nice. The GH4 doesn't have bad dynamic range, but the roll-off is pretty steep.

I am really curious to see how high you can push the ISO in APS-C mode, though. If it's clean up to 12,800 then there isn't much to complain about here.

July 26, 2014 at 8:34PM, Edited September 4, 11:56AM

0
Reply
Kenneth Merrill

I havent tested it but I would have thought the ISO in APSC would be just as clean as FF.

July 26, 2014 at 9:25PM, Edited September 4, 11:56AM

0
Reply

I did see one comparison and the noise was more visible in crop mode, but the scene wasn't super informative to me (wall atlas with ambient room light it looked like). I read somewhere you lose 2-3 stops of S/N usability in crop mode. Common sense would say 2 stops makes sense.

July 26, 2014 at 10:25PM, Edited September 4, 11:56AM

0
Reply
Kenneth Merrill

People who say stuff like "rolling shutter doesn't matter" generally shoot shit. *Checks webpage*. Yup, you shoot shit.

July 28, 2014 at 10:24AM, Edited September 4, 11:56AM

0
Reply
Terppa Teuvonen

Olympus recently filed a patent on solving the rolling shutter but I can see why a quicker sensor readout is tougher in a small body like A7s - more powerful processors produce more heat.
.
On a side note - 7D has been tagged as discontinued. Its replacement must be on the way.

July 26, 2014 at 8:38PM, Edited September 4, 11:56AM

0
Reply
DLD

Sony themselves recently filed a patent to substantially reduce/ remove rolling shutter. My guess is that the A7s could be upgraded next year with the new technology. I might wait till them.

July 27, 2014 at 1:06AM, Edited September 4, 11:56AM

0
Reply
Tone13

That slashcam detail test just made it a rule to shoot exclusively at apsc mode with the A7s UNLESS you absolutely need the FF look. Which is a good thing since a lot of native lenses awesome for video are only apsc (10-18/4 ; Zeis 16-70/4 ; G 18-105/4; 50/1.8 ; Zeis Touit 32/1.8 & 50/2.8 Macro and the awesome Samyang 12mm F2 for ultrawides [sharper than the Zeis Touit 12mm/2.8}.

July 26, 2014 at 9:03PM, Edited September 4, 11:56AM

0
Reply
gb

Coming from film where a whole frame represents an instance in time, I find rolling shutter to be totally unacceptable. IMO it undermines the artistic value of the moving image (unless the intent is to simulate artifacts of video).
.
That said, in a few years, sensor bandwidth will increase sufficiently that this will no longer be an issue for most high-end consumer cameras.

July 26, 2014 at 9:33PM, Edited September 4, 11:56AM

0
Reply
Matthew

Technically film cameras do have rolling shutters (or spinning shutters) but they're so fast you rarely run into problems. Quick flashes can still result in half exposed frames though.

July 27, 2014 at 4:59AM, Edited September 4, 11:56AM

1
Reply
dauid

$500 more for global shutter. A-a-anyone?

July 26, 2014 at 9:50PM, Edited September 4, 11:56AM

0
Reply
Natt

Let's see what A99 II brings. It might be $500 more or even $1,000 more but has a big body (A7s weighs 489g, A99 MK I 816g), so chance are it will have more features as well. I assume the internal 4K recording will be a gimme too.
.
Then there are new Canon products too. 7D MK II should be announced in a few weeks and 5D MK IV early in 2015.

July 27, 2014 at 1:39AM, Edited September 4, 11:56AM

0
Reply
DLD

I read today the 7D is now end of line. I cant remember if it was here or Cinema5D where I read it.

July 27, 2014 at 5:16AM, Edited September 4, 11:56AM

0
Reply

It may have been just a few posts above this .. or not ...
.
Btw, using a couple of HDMI to SDI adapters, one can record 4K off A7s already.

July 27, 2014 at 7:58PM, Edited September 4, 11:56AM

0
Reply
DLD

If you're shaking your camera around like an idiot, you deserve jello.

July 27, 2014 at 3:38AM, Edited September 4, 11:56AM

0
Reply
Paper_bag

Oh God, people.

Rolling shutter does NOT just affect the image when panning the camera at 600mm with a passing train in the frame. Rolling shutter affects every pixel of the image with ANY movement, whether by the camera or the subject.

A common example is handholding the camera, even if you're shooting a static landscape, you're going rp be affected by RS, not to mention if the scene is moving too. So a slow RS camera will severly limit its ability to be handheld.

Another example, even if you have the camera completely static and filming a moving scene, the image is going to skew. Whether it's a car passing, a person running, a sword moving, drum sticks, helicopter blades, hand waving, any movement really, you WILL be affected by

RS will affect any footage you shoot and just fast moving ones, it's the way the sensor scans the image, so even if you can't clearly see it, it's there to a degree. The only situation you're not going to see it is when the camera is completely still, and the subject is completely still, but that's called photography.

Like anything in life, how much you tolerate it depends on YOU. When I first started out I was very generous when it came to artefacts, I didn't mind aliasing and moire, I didn't mind noise and macroblocking, I didn't mind low resolution, I didn't mind lens imperfections like vignetting, softness and distortion, I didn't mind inaccurate skin tones, 8 bit 4:2:0 compression, and I didn't mind rolling shutter.

Now after progressing as a filmmaker, my productiom value needs to progress, and every one of these problems WILL lower my production value. So I don't tolerate image issues now, and neither do my clients as they become higher-end too with progress.

So it simply depends on you whether you can tolerate a given problem, but that doesn't give you the right to insult someone who cannot tolerate it to the same level, it's ridiculous.

July 27, 2014 at 4:08AM, Edited September 4, 11:56AM

0
Reply
Ebrahim Saadawi

What I'm wondering is how this is going to affect my glide cam work. Do I need to keep one of my FS100's around? (Was planning on upgrading all three to a7S). This would be ideal for my particular situation, but I need the glide cam work to look good when it does appear in my productions.

July 27, 2014 at 10:53AM, Edited September 4, 11:56AM

11
Reply
Daniel Inzitari

To anyone debating that rolling shutter doesn't matter to the public I would for the most part agree with you. However if your awesome story (that is so bad-ass that you could have filmed it with a potato and won an Oscar) requires any VFX work, you will want to avoid rolling shutter like the plague. The right camera for the job. That is all :)

July 27, 2014 at 1:29PM, Edited September 4, 11:56AM

2
Reply

A Creative Cow video on the Rolling Shutter Repair (on Premier Pro CS6) -
[ https://www.youtube.com/watch?v=7pmBxPuEIzg ]

July 28, 2014 at 1:47AM, Edited September 4, 11:56AM

0
Reply
DLD

I'm wondering how the rolling shutter of the A7s compares to the F3. I'm hoping to use the A7s in HD for steadicam work because of its light weight, and to merge with F3 footage. Any info people know about?

July 28, 2014 at 4:52AM, Edited September 4, 11:56AM

0
Reply

Steadicam rarely has major rolling shutter issues. I used to have a 7d that has way more rolling shutter than my RED One MX...but you only really get problems in lateral tracking moves (you look like you're operating crookedly when you knew you were keeping your horizons level), or of course, when fast moving cars make fast lateral moves...but all the rolling shutter problems of jello that you get with handheld are totally gone.

August 9, 2014 at 2:57AM, Edited September 4, 11:56AM

0
Reply
Daniel Mimura

Totally unrelated question, my apologies, newbie here who just bought the a7s for its low light capabilities. Is there something I can do to fix or minimize judder? I tested some panning moves (to see how bad the rolling shutter is) with the a7s the other day and judder is horrible. Thanks for your help!

July 28, 2014 at 12:57PM, Edited September 4, 11:56AM

5
Reply
Abe

Judder is frame rate.

Rolling shutter is different.

July 28, 2014 at 4:24PM, Edited September 4, 11:56AM

0
Reply
Steven b

You're probably at 1/50 shutter... which will produce a TON of stuttering / juddering when panning. If you go to 1/45 it's as smooth as butter without any frame stutter whatsoever.

July 29, 2014 at 4:59AM, Edited September 4, 11:56AM

6
Reply
Justin

Justin, thanks! I'll give it a shot today.

July 29, 2014 at 10:12AM, Edited September 4, 11:56AM

0
Reply
Abe

Hi, how do you set shutter speed to 1/45?

August 28, 2016 at 3:51PM

0
Reply