Rolling Shutter CMOS Artifacts

A

androbot2084

Carbonite Member
I was watching some paparazzi footage on the Hollywood TV show Xtra Xtra and Ive never seen so much ruined footage in my life. Everytime a flash bulb popped the screen would spit up into an overexposed and underexposed mess. JVC's split screen problem palled in comparison to this defect. Now I am not saying that the Sony XD CAM is total garbage. Under controlled lighting conditions or if you can avoid these extremes I am sure it is a fine camera. But if you belong to the paparazzi the camera will be totally useless unless you are a daytime shooter.
 
What you describe is not what I have witnessed with the XD EX. I didnt see HUGE overexposures or unders that ran long to ruin a shot.... the effect I witnessed while not ideally what I would like was simply the flash throwing out to only partial frame and was so fast etc. I think for the ENG crowd its a small annoyance of little consequence. In the narrative though, if this occurs trying to get a particular shot with one of many things that cause a flash it may be of greater concern.
 
WOW :shocked:...after seeing that music video I am now VERY CONCERNED about CMOS artifacts... the "banding" that occurs with the strobes is pretty obvious to my eyes!:huh: ....damn....(and we're supposed to get our red camera in January... )
 
Hmm...
I'm waiting for Barry to jump on this thread.

Barry does bring up a good point to understand what you're getting into before you buy something. Having said that, I crossed my fingers with the EX1, and bought one.

So far, I have not done all the tests, but nothing has bothered me so far.
I will try some flashes using different frame and shutter speeds.

Also, I believe RED has really tried hard to minimize any issues with the rolling shutter.
 
Holy sh** that's bad. So there may be a way to sync strobes with the RED, but is there any way to do that on the EX1? I'm assuming not, so what options would there be to produce and capture a satisfactory strobe effect in a controlled environment (aside from pulling out the HVX, of course)? Looks like the ENG crowd is still screwed though...
 
No surprise -- that's pretty much exactly what I would have predicted. And DXmetal's comment is exactly spot-on: if that particular effect is unacceptable to you, stick with a CCD and stay away from a rolling shutter camcorder. If you're going to be shooting where flashes are going off, and that effect doesn't bother you, feel free to consider rolling shutters.

As Steve said, Red has tried to control the rolling shutter artifacts. I suspect the effect would have been hideously worse had it been from an HV20 or other un-optimized rolling shutter cam.
 
Jason Wilson said:
damn thats not cool at all....I know if I were the client I would not be pleased with that banding at all... its sad a camera that nice has that effect
Click to expand...

EVERY camera with a rolling shutter is going to have that effect. And lots of other effects. If it has a rolling shutter, it's going to exhibit rolling shutter effects -- the company may be able to minimize the effect somewhat, but it's still going to happen under certain circumstances.

The longer these cameras are on the market, and the more people use them in more circumstances, the more reports we'll see of places where it worked and places where it failed.

All I've been trying to say is: educate yourself as to what the effects are, and make an intelligent, informed decision as to whether you find the effects acceptable. The rules of video acquisition have changed, and you'd better know what you're getting into.
 
How bad is it when you are filming say the US National Olympic Trials where flashes will be going off like crazy at the awards and maybe even during some of the competitions!?!?!?!

Holly Crap That Sucks!!!
 
The perfect technology does not exist, with CCDs, you don't have the rolling shutter problem, BUT just point the CCD camera at a very bright light and you risk getting a vertical line when the CCD column is overloaded.

Tube cameras had image lag, remember the comet trails caused by bright lights?

As long as you know the limits of any given technology, you are buying something with an understanding what to expect from the camera. If you don't like it, don't buy it.

The Panasonic HVX-200 has been around for about 2 years, so we know what it's like, but the Sony EX-1 is still new and we're only starting to discover it's strong and weak points.


Bob Diaz
 
ESTEBEVERDE said:
How bad is it when you are filming say the US National Olympic Trials where flashes will be going off like crazy at the awards and maybe even during some of the competitions!?!?!?!
Click to expand...
Well, it depends on how much the flash illuminates the frame. If you're talking about a stadium where flashbulbs are going off in the crowd, it'll probably be a non-issue. As long as each individual flash isn't radically changing the brightness of the scene.

Now, a boxing match, with reporters all around the ring setting off flashes, or at the awards podium, or at a press conference -- yes, that would be a worst-case example.

The point is, as I tried to spell out in my article, different sensors will have different artifacts, and while we're "used to" the vertical smear of a CCD, we're only starting to discover the impact that the rolling shutter is going to have. It *is* going to impact people's work, and the sooner you learn what it can or cannot do, the sooner you'll be prepared to make an intelligent decision as to whether a particular camera will work for your particular scenario. Perhaps the hardest part is getting people to understand that we no longer have a "one size fits all" scenario. Now we have cameras that simply can't handle certain types of shots.

I think a lot of shooters are in for some surprises, until this issue gets more well known.
 
Actually the paparazzi footage I saw was worse than the music video footage as far as rolling shutter artifacts are concerned.
But then we are talking about nightime footage with a barage of flashbulbs going off from the still photographers. That being said as far as the Olympics were concerned the problem with the 2004 Olympics was that the 1080i interlace footage overloaded the compression engine to such a degree that unacceptable blocking artifacts were present anytime there was fast motion. However the Sony XDCAM has progressive scan shooting modes that will reduce these artifacts. Even for 1080i networks a cameraman can choose the 1080p30 shooting mode which may not handle fast motion very well but at least the picture will not block up. Of course the Panasonic HVX-200 has a lot of progressive shooting options also.
 
I posted the following over at DV Forums following a private email I sent to a friend on the East coast and you would have thought I said something about their first born:

I have a very open mind regarding the Sony EX-1. I wish the HVX200 looked that good. I mentoned one thing that I saw while demoing the camera. It was not an in-depth test.

Basically the dealer had a little set (just like they do at trade shows) and I had zoomed in to grab focus on a child's ball and toys. I loved the image. Then I accidentally kicked the tripod with my toe and saw the image wobble. It was a "what the f..k" thing. So I did it again, and again, and the damn image moved like jello. The HVX sitting 1 foot away zoomed in on the same thing didn't. The HVX looked just like what you'ed expect when you kick the sticks. It just moved, not wobbled.

Now any shot that you accidentally kick the sticks on is a lost shot, it is going in the can, so it is not a deal breaker for the EX-1, just an observation. I did some slow pans, faster, and some whips. I did not see any issues, but I was by no means testing the camera, just making some observations.

The salesman, who knew that I had an HVX, and knows my interest in getting the EX-1 said that he had a customer who did some green screen work, so this info is now twice removed, and they said that the edges fell apart compared to the HVX. I didn't see it, so I really don't know (shoot me for mentioning it).

I really want to see green screen recorded to the chip at 4:2:0 compared to out the SDI at 4:2:2. I expect the 4:2:2 to look better than the HVX because of the resolution of the camera. But, when shooting to the chips, I do wonder what the 4:2:0 will do. That is about it regarding green screen.

Based on my 20 to 30 minutes with the camera, I like it, but will need more info to be sold. I do not like the buttons and their layout. Sure, a lot of this stems from muscle memory from my HVX and I can relearn. I can't expect it to be exactly like my HVX.

The thing that I disliked the most was that the focus assist button is on the right side of the camera by the record button. I would have greatly preffered it on the left near the focus ring. The buttons and switches felt more consumer than pro. I say this only in comparison to the HVX. Heck, it is a prosumer camera after all.

So besides the flash issue, I can surmise that a sharp or high frequency hit to the sticks or camera body might introduce a wobble on a static shot.

Again, not necessarily a deal breaker for some, just like the noise issue isn't for some of us with the HVX.

I am still waiting for the camera that can give me the advantages of both without the negative of either. Until then I shot my HVX if appropriate for the job and rent other camera's when the HVX is not quite right.

Rob
 
As a follow up to the above post, I will give new users far more slack. Sometimes all anyone is trying to do is add some info. No hidden agenda like my friend and I from the east were trying to convey over at DVforumns.

I got to see what it was like being a "junior member" some place else.

Rob
 
dvInsight said:
I posted the following over at DV Forums following a private email I sent to a friend on the East coast and you would have thought I said something about their first born:

I have a very open mind regarding the Sony EX-1. I wish the HVX200 looked that good. I mentoned one thing that I saw while demoing the camera. It was not an in-depth test.

Basically the dealer had a little set (just like they do at trade shows) and I had zoomed in to grab focus on a child's ball and toys. I loved the image. Then I accidentally kicked the tripod with my toe and saw the image wobble. It was a "what the f..k" thing. So I did it again, and again, and the damn image moved like jello. The HVX sitting 1 foot away zoomed in on the same thing didn't. The HVX looked just like what you'ed expect when you kick the sticks. It just moved, not wobbled.

Now any shot that you accidentally kick the sticks on is a lost shot, it is going in the can, so it is not a deal breaker for the EX-1, just an observation. I did some slow pans, faster, and some whips. I did not see any issues, but I was by no means testing the camera, just making some observations.

The salesman, who knew that I had an HVX, and knows my interest in getting the EX-1 said that he had a customer who did some green screen work, so this info is now twice removed, and they said that the edges fell apart compared to the HVX. I didn't see it, so I really don't know (shoot me for mentioning it).

I really want to see green screen recorded to the chip at 4:2:0 compared to out the SDI at 4:2:2. I expect the 4:2:2 to look better than the HVX because of the resolution of the camera. But, when shooting to the chips, I do wonder what the 4:2:0 will do. That is about it regarding green screen.

Based on my 20 to 30 minutes with the camera, I like it, but will need more info to be sold. I do not like the buttons and their layout. Sure, a lot of this stems from muscle memory from my HVX and I can relearn. I can't expect it to be exactly like my HVX.

The thing that I disliked the most was that the focus assist button is on the right side of the camera by the record button. I would have greatly preffered it on the left near the focus ring. The buttons and switches felt more consumer than pro. I say this only in comparison to the HVX. Heck, it is a prosumer camera after all.

So besides the flash issue, I can surmise that a sharp or high frequency hit to the sticks or camera body might introduce a wobble on a static shot.

Again, not necessarily a deal breaker for some, just like the noise issue isn't for some of us with the HVX.

I am still waiting for the camera that can give me the advantages of both without the negative of either. Until then I shot my HVX if appropriate for the job and rent other camera's when the HVX is not quite right.

Rob
Click to expand...

Are you sure it wasn't the OIS that was on. That gives a Jello effect if you bash the camera.
 
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