Strobing / flicker effect when panning in 24p
 

Someone please tell me this amount of strobing isn’t normal when shooting in progressive mode…

Link to uncompressed footage (192MB).

Link to compressed footage (19MB).

Theses were the settings: PAL, 35 mbps (VBR), 25p, 1920 x 1080. Shutter 1/50, manual iris, gain -3, manual white balance and manual focus.

This is my third camera, the first had the light fall-off problem (aka vignetting), the second had a focus problem and this the third, seems to have this strobing problem, although I did notice the same strobing on the second camera also.

I used to have a Canon A1 and never experience this problem shooting progressive.

Any help would be appreciated.

Regards,

Simon

<Theses were the settings: PAL, 35 mbps (VBR), 25p>

this is normal in progressive mode….... I have the EX1 and the XHA1 (PAL).

All are from B&H, I didn't want the first one sent to Sony, as some people were getting there cameras back and still experiencing the same problem. I spoke to sony regarding the second one and sent them the footage; they agreed the camera was faulty but they did not know what the fault was even after it to their head engineer. So it was a case of either sending it back to Sony with no estimation of how long it was going to take or an exchange again. There seemed to be so much wrong, I opted for the later.

Hi Wolfgang,

I too had the PAL version of the XHA1 but it didn't have this strobing effect like this. This has to be clearly unacceptable, it unwatchable.

So are we saying we can't use progressive with anything that moves in this fashion?

Regards,

Simon

I have only watched the compressed material. Am downloading the uncompressed right now. The footage on the web had a lot of irregular strobing but this should be expected watching something filmed at 25 fps on a 60 Hz computer monitor. Are you saying that it is also strobing in an irregular way on a 50 Hz monitor?

This seems to be a judder problem, or I'm totally wrong.
Don't know why this happens with your camera though.

Tried a factory reset?


regards Dennis

wow... I have not seen anything like that from mine....

you sure it's the camera and not a software problem? almost reminds me of cineframe from the z1/fx1.... like it's a pull down issue.

your not going from 25p to 24p on export are you?

So, I've watched your uncompressed material with zoomplayer (vlc shows a similar problem).

Seems ok!

Simon: For various minor reasons I was thinking of asking B&H to exchange my camera but I didn't know how to approach it. How did you get them to change your camera 3 times?

I haven’t had chance to view it on a proper monitor, I was initially concerned that I could not view it on a computer monitor. I will hook it up when I return home on Wednesday.

It seems to play okay in the camera, which I guess suggest the camera is fine. However it’s hard to really tell being that the LCD is a bit too small to see this.

I think you’re right; it seems to be a software issue. As for exporting from 25p to 24p; no, as I’m not exporting when just viewing in XDCAM Transfer and Clip Browser.

Thanks for everyones help and comments, please keep them coming. I'm also speaking to Sony to see what they can come up with.

Regards,

Simon

To me it sounds like you are just experiencing what happens when you playback on a monitor with a frame rate that is not equal to or double the recording frame rate.
I would not bother Sony with this before looking at the material on a 50 Hz monitor.
Another way would be to make another recording in 30P och 60i and playback on a computer monitor. That should not produce the jitter/strobe problems.

Just a wild guess but... um... Rolling Shutter?

Remember that those films did it on Global Shutter CCDs, not rolling shutter CMOSs.

I understand your issue, I have same and when zooming but your pans are way too fast. As a film student you should know the MPEG suggestion is that an object in the image should take at least seven seconds to cross the screen - yours took about two. Do the test again adding zooms with slower speed and lets see what you get.

Wacth any hollywood action movie and you will see any speed pan to be better that what we are seeing here. From 1 second to 14 seconds.

There is just too much judder. Yesterday I did some shooting out in the forest and I had the camera focused on the character with the trees behind him. The camera was on a shoulder mount but I was not even moving it and I saw some judder when I followed the character as he walked slowly from left to right.

Even very slow movement gives a wierd looking flicker/judder effect. I'm surprised more people have not brought up this issue as much as the backfocus issue. To me, this is more annoying than the backfocus problem.

I raised this issue back in Feb and it's like nobody understood what I meant. Try panning a line of verticle posts (like a line of tall straight trees) and see what you get. Ugh! Try zooming in 24p and you will see the center where rolling shutter has no issues is still while the further you get to the outside of the frame where lateral motion increases it pulstaes and flickers. For me zooming and fast panning just are not on with this camera.

The reason it has not been brought up is because this issue is not unique to the EX1. Try a side by side with another camera at the same settings and you will see.

The notion that the EX1 "renders motion" differently from other cameras (aside from the known issue of how the rolling shutter works) is a canard.

Nonsense Eric, I've not seen it with any other camera I've used. It obivously is a rolling shutter problem. Varicam doesn't do it, Sony 750 doesn't do it, Sony Z7 doesn't do it, Digibeta cameras don't do it, Canon Ex-1 hi-8 doesn't do it!
What you do get from Varicam etc. is a motion blurring but it's subtle. This is just horrible and I think totally unuseable for action shots.
Steve

I am curious if the other Cinealta cameras have a similar judder/flicker effect when doing slow or quick pans. Anyone have any f-900 or F350 footage we can check out?

Is there anything that can be done to reduce the flicker? There is a "Flicker Reduce" setting in the menu for 50hz and 60hz but I don't know if it is for that.

None of the other Cine Alta cameras will do it 'cos none have a rolling shutter. I've used an F900 and it's fine. The only way to reduce is to slow your pans down. Incidentally, the Phantom HD also has a rolling shutter but I've never seen an issue with it, I assume it must just scan the image a lot quicker (it goes upto 1000fps so I gues it needs to, and you pay abut £100,000 for this ability!)
Steve

I don't understand what "subtle" motion blur is. Perhaps you can post an example of unsubtle vs. subtle motion blur?

Motion blur is regulated by the exposure time and how much the action before the lens changes during the exposure. Longer exposure means more blur. Shorter exposure less blur. Gamma can affect the hardness of the edges of the blur, but only subtly. Very bright things tend to have a hard edge blur because they saturate the sensor quickly. There's really not much more to it than that.

Rolling shutter is definitely there, and visible, and sometimes ugly, but it does not affect the "subtlety" of the motion blur.

It flickers even in the slowest movement though.

Eric, I'm saying that they are 2 different things. Motion blur is always there in progressive, but it's subtle, more subtle the faster the shutter speed. But the effect of the rolling shutter is not subtle, it's ugly.
Steve

Here is an interesting article that will shed some new light on this subject.

http://hd24.com/dont_shudder_at_the_judder.htm

I have to disagree. Rolling shutter is not noticeable under normal conditions, but tends to reveal itself at the extremes. The judder you see is not related to the rolling shutter nor is it unique to the EX1.

If it's not the rolling shutter then what is it? Varicam/Sony 750 don't do it. They're the cameras I mostly work with, and they don't look like the EX1 does.
Steve

Please figure it out and tell us all. Post clips if you can.

I can assure you it's not the rolling shutter.

I noticed, that the vlc-player plays videos more smoothly than the quicktime-player does (I'm using a mac). At 24p the vlc-player produces that typical 3:2-pulldown-look when viewed on a 60Hz-Display (like almost all LCDs do have), but the quicktime-player does it a bit more jerky. Another example is 60p: With vlc it's perfectly smooth, but with quicktime there are periodically emerging kind of synchronization-problems. I wonder how long we have to wait, until apple fixes that. Perhaps somebody has to tell it apple?

Do most of you play back your footage on a big screen HD tv?

Some things that may come into play as far as why there is flicker can be the actual television signal being that it is 3:2 pulldown... streaming it through component cable which is not true 1080p.

Just a couple of things that may be a factor.

Has anyone converted their xdcam files into film? If so, what was the outcome?

I'm not crazy after all!
 

I'm glad I saw this thread. I thought I did something wrong with my new EX1 or that my lasik didn't quite take. Even when shooting in 1080p or 1440x1080i I encounter the panning issue. I don't have the same problem with my cheaper Sony V1U HDV camera. I expected more for the bigger price and touted capabilities.

Mark,

I really don't think there's a problem with the camera. There certainly isn't a consensus here on that. Just conjecture.

Then I wonder what settings are making my same movements that I make with the V1U look so bad with the EX1.

I have output to Bluray disk and played from Sony Bluray player via HDMI with SAME effect. This si not a playback issue.

Can you post footage from both? If possible, attach the cameras together on the same pan head (use tape?), set the lenses for the same field of view, put them at the same frame rate and shutter, and do some pans.

I couldn't download the samples so im not sure what we're all looking at. Are there any more examples?

I've not found anything disagreeable or unexpected in any of the footage we've shot.

Im on 25p, so is this something specific with 24p only?

cheers
paul

Stobing effect in EX-1 while Panning
 

I am getting a strobing effect while panning on the EX-1. Is this normal? I am shooting 1080i shutter speed on at 60. I see the strobing effect while viewing in the browser software and in Vegas pro 8. Will this continue once rendered in final form to DVD? Please Help......

Your browser interface and NLE may not preview at full speed (you can see in Vegas Pro 8 what is the actual playback speed). To check for your self, render a portion to avi and playback in your favourite player. I've not experienced any problems of unexpected strobing or unsteadiness.

I have been reading this entire thread and I can confirm that this camera as a judder problem. I was all excited getting this camera and being able to shoot in 24p, what a deception. I had better results with my PD170 shooting at 29.97 interlaced then converting it to 24p in Vegas 8. Even better than the EX1 at 30p. I could do some fast pans, actions shots, it looked like film with my Letus adapter. The only trade off would be a slight doubling only on very fast motion area, but it doesn't make you dizzy at all. Had no restriction when shooting!

I also have color problems and thinking about returning it.

This is a fundamentally different thing. You can't compare post processed 60i to 24p because the time sampling is completely different.

These judder threads are getting out of hand in my opinion. No one has presented a side-by-side showing that the EX1 is any different from any other 24p camera.

There's really not enough conceptual complexity to motion picture photography for there to be such stark differences in the way cameras record motion.

Agree. It seems to me that 24 fps is 24 fps whatever you shoot with. What differences are there between shooting 24P with video compared to film? Rolling shutter compared to global shutter. Is the rolling shutter a problem in pans? Not that I can find. So is the camera not recording progressive images? Looks OK to me. Seems to me that people used to shooting 60i are adopting 24P without changing their techniques. I note that Phil Bloom has set up a film competition to encourage us all to get out and make films.

I disagree. I was watching The Bourne ultimatum (Shot on Arri Film Camera) and even the most shakey scenes were smoothe with no judder. There was not 1 instance that replicated the problem that the ex-1 has. The 24p that this HD camera does and the ones I have seen shot on film is totally different.

You can either choose to believe that there is no difference or come to the realization that there is a reason that the cameras they use on those kinds of movies cost over 200k

I can't see any point to that comparison. Film cameras are expensive for good reasons (as are high end video cameras), but looking at your own material shot with the EX1 and some professional feature film tells you nothing. You don't actually know the shooting frame rate nor the post production processes. To get to basics, shooting at 24 fps a film camera exposes one frame at a time, 24 times a second. So, I'm told, does the EX. Now you explain the difference in technical terms rather than by hand-waving assertion.