Sony AX100 4K video camera - how much rolling shutter is too much?

[Andrew Reid]

The Sony AX100 takes the relatively large 1" sensor from the RX10 and puts it in camcorder form factor with built in ND filter. However it appears that in reading out all the pixels on a 20MP sensor, Sony have created a skew-monster in rolling shutter teams. What's remarkable about this video is that the panning and trains aren't even moving very fast. This is some of the worst rolling shutter I've yet to see on any camera available on the market.

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[Jeff Orig]

That's not rolling shutter.  Those trains are actually bending the space-time continuum.

 

;)

[Musty]

Horrific! Simply unusable for anything with too much motion.

[TJB]

In a few years time - the next generation of film makers will seek out plugins that will imitate all the video abnormalities we dislike today.

Plugins like the film grain, scratches, dust and light leaks etc (over) used by those seeking the "film look" today.

 

Looking forward to NAB to see Canon and Sony's answer to the GH4.

[Julian]

Yikes. :blink:

 

The faster the read out speed of the sensor, the less rolling shutter. Maybe it is _because_ of the fact that it is reading out the whole sensor, that it is so bad? Read out while pixel binning or line skipping maybe works faster than reading out all the pixels?

[tpr]

There are some panning shots in this AX100 clip from around the 7:40 mark, but there doesn't seem to be anywhere near as much rolling shutter as in the other video:

 

[jcs]

Perfect for babies, kids, puppies, kittens: the target mass market & youtube :)

Plus a nice $2k way to create very crisp, 444 8.67-bit 1080p.

XAVC-S looks to be a decent codec.

120fps, ND's, Zeiss lens, good low-light (per Sony), good image stabilizer, might be a nice camera for the price.

 

The camera has a very good image stabilizer- that also 'helps' make the rolling shutter more visible: 

(1080p60 much less RS).

[Guest Ebrahim Saadawi]

Yes I mean I hope you don't dismiss the camera alltogether because of this Andrew. It seems to have great potential. It might even be "the" camera that brings 4K actually to the masses not the GH4! I can imagine the amount of online/youtube channels switching to 4K with an easy/fixed lens camcorder with great features. Even soccer moms can enjoy 4K now! :D (And soccermoms ARE the masses!)

You're one of the very few people we trust reviews from, so try to get it and test as subjectively as possible please :)

[maxotics]

Maybe because it was shot in bright sunlight a high shutter speed got in front of the readout.

[Guest Ebrahim Saadawi]

Oh God. I just watched the video you posted JCS, the image is a moving sea of jello at 4K! It really is bad. The 1080p footage seems to have less rolling shutter than most cameras in the market though. Weird.

[jcs]

Most of the kid-tracking footage in 4K looked OK. His kitchen whip-test showed pretty strong RS. Not clear how it was processed, but noise looked well controlled. Reading the JP converted to EN sounds like there was concern with low-light (the translation wasn't clear to me).

 

Maybe the 4K has a lot of RS so folks won't dump their FS700/F5/F55 ;) (I still haven't upgraded my FS700 for 4K yet, though I might do the upgrade in order to use the Odyssey 7Q to shoot the new 4K => 1080p 10-bit ProRes just released (looks great)). 4K is certainly useful for super-high quality 1080p, reframing, stabilizing, etc. (not delivery for a while- same pattern we had when HD first came out).

[sam]

Yeah Jcs, Lucky you! I pixel peeped various raw files out of the fs700+ 7Q and they looked good.  

 

 2k 12 bit raw 240fps, 4k raw 60p,  (according to dvx...I believe,  It's not on CD's site that I could find)   4k 10bit compressed, and now 4k from the sensor to 1080 10 bit Prores that you mention, or an array of other compressed options or frame rates.

 

$6800 for ebay fs700 + $400 for upgrade from Sony + $3800 Q7 package  =  $11k    (+ very fast cpu to render all that raw)  

 

Also one  can use a speedbooster, different Nex adapters  or  the 18- 200 power zoom from Sony and have have super35 high frame rate ENG style cam.  

 

 Some complaints about the form factor, but a bare fs700 weighs almost exactly the same as a 1dc, and now without the need for Sony's lenghty and more expensive  add-on recorder, it's a fairly compact 4k camera and the softer footage of the avchd is only necessary when its wanted

[Orangenz]

Oh God. I just watched the video you posted JCS, the image is a moving sea of jello at 4K! It really is bad. The 1080p footage seems to have less rolling shutter than most cameras in the market though. Weird.

Indeed, on 4k it becomes ultra-jello-cam. Still, absolutely stunning image if nothing is moving... The 4k played back at HD is definitely a nicer image too.

[jcs]

Sam- after working with 5D3 raw, if I get a 7Q it will be to use ProRes or DNxHD 444 or 422, 10/12 bit. Raw is really only needed to perform better debayer (if using 12-bit). If the O7Q debayer is OK (looks like some purple fringing still needed to fix), then being able to edit straight from camera and save tons of time and disk space is the preferred way to go. I'd actually prefer XAVC (long GOP) to get even smaller files with high quality. If there's ever a need to go to a better camera, the ARRI Amira looks really good as a next step (vs. F5/F55). That said, going the other way to a GH4 is also looking tempting based on footage posted: 

(start around 5:52 for charts & skintones). Will be interesting to see how this 4K Sony camcorder compares.

[DVCinLV]

 

What's remarkable about this video is that the panning and trains aren't even moving very fast. 

 

So you copy someone's horribly shot video and come to a conclusion. Based upon your conclusion, it's best you go to a film school and learn how to pan at 24fps.

 

You've got to be kidding when you say the panning isn't fast!  It picks up speed to beyond any reasonable rate. And, do you have any idea of how large the motion vector is when you stand a few feet from a moving object.

 

Any competent shooter would follow the train -- and when that was done in this clip the train looked fine.

 

For those of us that actually own the camera -- there is no RS problem if one shoots as one should 24fps film.

 

 

[Orangenz]

 

"For those of us that actually own the camera -- there is no RS problem if one shoots as one should 24fps film."

 

It's a handycam for the masses, actually. And definitely the worst rolling shutter I could imagine. And once you know it's there you can see it on pretty much any shot that has movement. But no one is saying it isn't an amazing camera in many other ways.

 

 

 

 

[hmcindie]

That looks exactly the same as most rolling shutter cameras.

 

Shot with a high shutter so it looks extreme but motion blur does tend to hide it.

 

There is a thing about doing tests properly because eyeballing stuff just gets these ridiculous overboard examples: "OMG LOOK AT THAT!"- while the rolling shutter is about 90% the same on these cameras.

 

The reactions some people get to these silly videos is so overboard I'm laughing my ass off.

[etidona]

 

 

 

 

For those of us that actually own the camera -- there is no RS problem if one shoots as one should 24fps film.

 

 

 

there is no such thing as "should" in filming. Fast movements are allowed also in 24p and so are train stations ;) 

[TJB]

Pixel peeping always amplifies the effect. If you have a strong story to tell then rolling shutter won't get noticed by most of the audience. Even if they do notice - they probably won't care. You could alway try and hid rolling shutter with film effects like dust and scratches. 

An example -

[maxotics]

Pixel peeping always amplifies the effect. If you have a strong story to tell then rolling shutter won't get noticed by most of the audience. 

 

That's so true for everything.  I was amazed at the amount of barrel distortion in "Nebraska"  In fact, if you watch professional shot network TV shows you'll see all kind of problems.  Every time I point something out my wife is like "Whaaa?" :)