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pidulgi
06-01-2016, 11:31 PM
Hello guys. I recently sold my BMCC and got a BMPCC.

Except the expected differences due to the smaller sensor, I noticed a very large difference in the motion blur of the footage. The motion looks way more "choppy" than expected for 180 degrees. Instead of motion blur I see displaced copies of the object. Like the footage was shot at much faster shutter speed and lacks the proper blurring between the frames. So, in many cases it almost makes me feel dizzy watching it. This is nothing like the footage I watched for the BMPCC online which looks just like to what I'm used from the BMCC when it comes to motion blur. What could possibly cause this? Could be a sensor malfunction? Am I doing something terribly wrong? I have never used a DSLR for video nor my eyes are used to "30fps" as I rarely shoot such content. BMCC was my first camera to shot video with and I have completed several projects which all have been at 24fps. This is definitely different than the BMCC and what I'm seeing onilne for the BMPCC.

So here are some facts:
- I'm using a Metabones EF - BMPCC T Speed Booster
- EF-S 17-55 (with the plastic removed to fit the adapter)
- IS doesn't seem to affect my problem but of course for the sake of any tests it was turned off
- I have tested with a couple of EF adapted vintage lenses as well and the effect is unchanged
- I'm aware 180degree shutter angle in the BMPCC used to be a problem years ago but it was fixed with an update. The camera is upgraded to the latest firmware. In fact I downgraded and upgraded again to double check.
- I shot 24fps. I have tried 23.98 as well no difference.
- At 30fps 180 shutter the motion blur looks as it's supposed to look for 30fps. Edit: in fact it seems to also be weird.
- I have shot footage indoors and outdoors and the effect is same

The effect is observable in all situations. From major camera motion (which shutter weirdness is expected) down to very subtle movements. In fact even with the camera steady, the effect is observable at any moving subject regardless the speed of movement.

What do you think about it? Could it be that the camera couldn't upgrade properly and I'm still suffering from that old shutter speed problem? Is this probably normal and I'm too "spoiled" from the BMCC? Your feedback is very much appreciated.

Here are some grabs demonstrating the "ghost" effect

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Here is what I am expecting to see.
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UPDATE!

So, first of all, talking about motion and shutters, it was very easy to get confused and mix up some different things into one:
1) the judder - the strobe-like effect where the image seems "jumping" caused by the camera movement
2) the weird motion blur - the lack of proper bluring between the frames

After extensive testing here is the conclusions for number 2:
Captain Hook and anybody else that suggested something is off because of lighting were right. The "ghost" effect with the multiple copies of the objects (such as the finger pictures posted at the beginning of the thread) was indeed caused by the specific LED lights I am currently using in this room. I changed all fluorescent lights of this room into LED just a month ago. I only filmed with this new room lights twice with the BMCC. Looking up that footage as well as older footage and new additional tests concluded 100% that the ghosting doesn't happen in other conditions including daylight.

Number 1:
Judder is a little more complicated as there is no exact definition of what's "appropriate" or "acceptable" judder. Much of the testing content I posted is definitely not the kind of material I would normally shoot anyways. In addition the BMCC was not exactly the camera that I would carry out with me and move around like I did with the BMPCC. So the lack of observing any significant judder might be because I barely shot anything of that kind.

That said, I'm still not sure about number 1. The only true way is to get another pocket and shoot together. Regardless, please still feel free to write your opinion about the videos, especially the judder.

I hope this experience of mine is useful to anybody else experiencing this problem.

DPStewart
06-02-2016, 12:01 AM
Yeah... Someone recently brought this up. They had some footage of a drummer and the drumsticks were doing that. I think they found a solution.

My BMPCC's don't show that.
I wish I could remember the solution for you - but I wanted to chime in and at least tell you that I'm pretty sure there is one.

EYu
06-02-2016, 12:37 AM
My BMPCC does not have that issue too. We could have traded my BMPCC for your BMCC and you won't be having this issue. :)

CaptainHook
06-02-2016, 01:03 AM
Are you BMPCC examples under artificial light? Try outside under daylight.

DPStewart
06-02-2016, 01:17 AM
Are you BMPCC examples under artificial light? Try outside under daylight.

Ah, that's right - certain kinds of lights can trigger the multiple-image effect. Can't remember exactly what kinds they were though....

Revdesign Industries
06-02-2016, 01:24 AM
I had some led Christmas lights that I could swear they had a very fast flicker to them, just right there on the edge of being perceived as not fluid or continuous. This was super confirmed when I shot with the bmpcc. The strobing showed up and also in motion blur. Not saying your ghosting is coming from this. But lots of artificial ligero is going to have some form of flicker unless it's filament based light. These things, just like your computer monitor refresh rate, can interfere with the captured blur.

pidulgi
06-02-2016, 01:26 AM
Thank you so much guys for the reply.
Here is a quick upload of something I shot a few days ago. I'll upload a new one in a bit.
Again 24fps 180 shutter. Natural light and ND.
I'm not sure if this is what I should be getting. The blur at the cars does seem kind of unnatural to me. Is this normal?
On the other hand, what are the artificial lighting conditions that could cause this problem? My home lights used on those examples are just roof LED lights. I observed the same effect even when I'm using my filming lights.
Now the weird thing is that I've been using the BMCC in the exact same environment just fine.
Thanks again.


https://vimeo.com/169051922

EDIT: I just shot a couple of other tests in daylight. I believe the same problem is there. What do you think? Is this normal? I have never seen this kind of shutter with the BMCC. It feels like a 90 degrees with more motion blur or 180 degrees with no motion blur. Weird but not sure. I would appreciate your opinion.

https://vimeo.com/169055182

4saken
06-02-2016, 02:37 AM
what version of the firmware are you running? wasn't there a bug in the really early firmwares where you had to pick a shutter just below 180 because 180 on the spot was causing problems?

pidulgi
06-02-2016, 02:43 AM
what version of the firmware are you running? wasn't there a bug in the really early firmwares where you had to pick a shutter just below 180 because 180 on the spot was causing problems?

Hello thank you for the reply. Yes, indeed. I mention about it in the top of the thread, I'm running the latest firmware. I even downgraded and upgraded just to make sure.

stip
06-02-2016, 03:27 AM
I also once or twice brought up this issue here but can't remember anyone know any solution to it, it wasn't even considered an issue by many. Which is funny because even a director once asked me about the strange motion blur. There has been a thread trying to find out what's going on some time ago but the guys couldn't do more than try to figure out why it is like that.

It has nothing to do with the early firmware bug, artificial light sources or wrong shutter speeds.

Maybe the bad/ghosting motion blur isn't there on all Pockets, just some like mine and yours?

DPStewart
06-02-2016, 03:27 AM
I hate to be the one....
But I think this is a camera failure.

Howie Roll
06-02-2016, 03:32 AM
The bug in the original pocket firmware, 1.42, was that 180 degree shutter was actually 360, people got around this by setting the shutter to 172.8. It was still strobey.

The strobing motion blur continued for another firmware or two and was eventually, silently resolved, firmware 1.6ish.

The problem with LED is PWM dimming vs voltage dimming. LEDs that use PWM dimming will actually strobe to create the perception of a dimmer light when in reality it is just flickering very quickly. The frequency of LED at 100% should be imperceptible to you and your camera at any normal shutter speed.

This is the same problem with monitors, refresh rate hasn't been an issue since CRT. A monitor that has a 60hz refresh rate is progressive and the cycle between refreshes is miniscule it doesn't really go to black between frames. The problem comes from backlight dimming. Apple monitors don't do this at all, most others do.

You should probably be on the last pocket specific firmware. I can't remember right now, I think it's 2.2ish. Not all firmware updates work the same way. I tried to roll back the firmware to 1.42 to fix an audio issue and it didn't take. I lost audio meters and a few other changes but the audio gain structure wouldn't revert to it's original state. There are changes in the background that aren't publicized but they exist (conspiracy theory), originally the rec709 @3200 out of the camera was practically unusable it was so desaturated.

stip
06-02-2016, 03:36 AM
happens outside in daylight too.

pidulgi
06-02-2016, 05:51 AM
I also once or twice brought up this issue here but can't remember anyone know any solution to it, it wasn't even considered an issue by many. Which is funny because even a director once asked me about the strange motion blur. There has been a thread trying to find out what's going on some time ago but the guys couldn't do more than try to figure out why it is like that.

It has nothing to do with the early firmware bug, artificial light sources or wrong shutter speeds.

Maybe the bad/ghosting motion blur isn't there on all Pockets, just some like mine and yours?

Thank you for the feedback. Do you by any chance use a speedbooster as well? I'm trying to eliminate it as possible cause. I have a couple of vintage EF adapted lenses so I know it's not a lens problem but have nothing to test directly on the M43.

pidulgi
06-02-2016, 06:34 AM
My BMPCC does not have that issue too. We could have traded my BMPCC for your BMCC and you won't be having this issue. :)

I wish I was thinking like that and just list the camera here or other BMCC forums.

pidulgi
06-02-2016, 06:44 AM
Btw, I have been updating through versions just to test things. It didn't change anything to the weird ghost/motion blur situation but I observed that an error message will come up on the latest update for the pocket (2.1) or any higher version which pretty much still updates the pocket camera to 2.1. The error message says "Updating the camera software failed." and it comes right at the end of the upgrade process where you expect a confirmation message. When I connect the camera it reads as 2.1 and up to date. I think it's probably a wrong flag and most likely has nothing to do with my problem, I just wanted to see if anybody else is also getting this.


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stip
06-02-2016, 08:02 AM
Thank you for the feedback. Do you by any chance use a speedbooster as well? I'm trying to eliminate it as possible cause. I have a couple of vintage EF adapted lenses so I know it's not a lens problem but have nothing to test directly on the M43.

Yes I do. BMPCC Speedbooster for EF lenses. It's not the speed booster, happened without it too.

froess
06-02-2016, 10:02 AM
Yep, happens to me to. But for the kind of work that I do with the pocket, doesn't bother me that much. Would like to know if there's a solution though.

froess
06-02-2016, 10:04 AM
But if I remember correctly, I was shooting at night with 360 shutter angle and fast moving objects. So I was kinda asking for it.

EYu
06-02-2016, 10:48 AM
But if I remember correctly, I was shooting at night with 360 shutter angle and fast moving objects. So I was kinda asking for it.
That's normal and not the problem expressed here... and yes you were asking for it. :)

Truemotion
06-02-2016, 12:16 PM
Yes pocket has not the best motion blur. I think you should have already seen it in web videos all over around. Thats the other side of smallest camera with great DR.

froess
06-02-2016, 02:31 PM
That's normal and not the problem expressed here... and yes you were asking for it. :)



Definitely. But even so, the motion blur is not pretty and traditional as you see in other cameras.

4saken
06-02-2016, 05:33 PM
Something is definitely wrong with the motion blur in those clips. I've never witnessed anything like this on my pocket cam.

pidulgi
06-03-2016, 01:29 AM
Thank you guys for your replies, advice and confirmation. It really seems like this is indeed a faulty camera :( I contacted the person that I bought the used camera from 3 weeks ago but realistically I don't expect an honest answer or refund. I also contacted Black Magic but even if they confirm the camera is faulty what can they possibly do about it. I was just hoping for a quick costless switch from my BMCC to the BMPCC but I lost a lot of time and money on this... I guess I will first wait for BlackMagic's answer and then I will try to find another pocket camera and sell this off as faulty or such so I can at least get something off my damage back. If anybody is interested feel free to make an offer as I really rather not pay a cut to eBay. Other than this problem the camera seems to be totally fine and can be usable for secondary situations.

Here is the latest of the test videos that exhibit the problem in a pronounced way. It's like the camera "forgot" to add the motion blur or something. Not sure what's going on.

https://vimeo.com/169194017

DPStewart
06-03-2016, 01:36 AM
I suspect that "somehow" the software update is not working. Like it didn't "take" even though the new version number is displayed.
Because the old 360-degree shutter bug is the only thing that explains this behavior.

There is no actual shutter obviously - it's a function of software, so....

pidulgi
06-03-2016, 03:16 AM
I suspect that "somehow" the software update is not working. Like it didn't "take" even though the new version number is displayed.
Because the old 360-degree shutter bug is the only thing that explains this behavior.

There is no actual shutter obviously - it's a function of software, so....

Thanks for all the feedback. The thing is the rest of the interface updates normally. Also when I update to any slightly previous version (like the 2.01) the update completes without any error and everything in the update seem to be working as promised. I also thought that this could be the shutter problem from the older versions but back then it seems the problem was just with the 180 and you could get away with it at any other shutter angle. But this problem exhibits it self no matter then frame rate / shutter / lighting combination :/ Since yesterday I have repellently done so many tests at any combination, shutter angle, camera angle, lighting, movement speed, subject movement speed etc trying to convince myself something else is responsible for this, not the camera itself and that there is a solution. But the strobe effect persists on each and every test... The guy I got the camera used from claims he has no clue about it and talk left and right avoiding my refunding demands (honestly I can't really put pressure about it on him anyways since the transaction was local in cash). To be honest, judging by everything else I highly doubt he was really aware about it. In any case, camera's out of warranty, one BM retailer/service here said immediately "buy a new one it will honestly be cheaper" after checking the serial number and explaining the problem. So my last chance is BM support maybe they suggest something but I highly doubt it.

ru31jan
06-03-2016, 06:41 AM
You're absolutely sure you don't have IS on? Because I have noticed that stutter effect with IS lenses. Can you try with other lenses?

Howie Roll
06-03-2016, 06:50 AM
Other than the first couple stills that you posted I'm not seeing anything abnormal about the motion blur, all the videos looked just about right. Panning left and right on the car shot the body panel seams just became fatter and softer but didn't have any strobey repetition like the pocket had in the early days, these would be a sure tell of some messed up motion blur. This might be a playback issue, I'm not seeing anything funky on my end.

stip
06-03-2016, 07:33 AM
Your latest video looks ok here too.


I think we need to clarify what issue of the motion blur you/we are talking about;
I thought it's about the 'ghost' effect, where you will see multiple (2 to 4) images (of the moving object) stacked on each other - instead of a single, blurred image (like in your first example pictures)?

This issue has been discussed before here and there were theories about read out times ect but no solution as far as I remember.

pidulgi
06-03-2016, 09:13 AM
You're absolutely sure you don't have IS on? Because I have noticed that stutter effect with IS lenses. Can you try with other lenses?

Thanks for the suggestion. If my IS was on I wouldn't say it's OFF :) In any case, I have two other vintage lenses with no electronic parts whatsoever adapted to EF. Exact same behaviour.

pidulgi
06-03-2016, 11:14 AM
Ok... So after some of you guys said it looks fine, I kept doing some tests. This time I took out my Nikon D7000. To my surprise I can see some similar strobe-like effect in various lighting conditions. So, I feel like I'm getting a little crazy at this point. Surely this fast movement is not an everyday situation and I'm exaggerating for testing purposes. I really want to believe my BMPCC is fine but to my eyes something has been wrong thus starting this whole thread. I hope it's just my mind playing tricks but some people already said that something is definitely off when they saw the first images and videos. So I uploaded a pretty extensive testing video seeking for your opinion and advice. If the camera is bad indeed then I would like to know about it so I get another one. If I'm asking too much of your time, feel free to skip at around 4:00 at the tomatoes part. Please watch at a little larger window at the Vimeo site. Thanks again for all your feedback.


https://vimeo.com/169260184

Howie Roll
06-03-2016, 02:53 PM
Looks like 24p playback judder to me. Are you shooting 23.98 or 24? What happens if you shoot 29.97?

pidulgi
06-03-2016, 03:13 PM
Looks like 24p playback judder to me. Are you shooting 23.98 or 24? What happens if you shoot 29.97?

Thank you. I might have been a little too extreme at my tests and what we are seeing might indeed be natural. This is all shot @24, put on a @24 timeline, exported as 24 :) 23.97 has not difference to this. Also did tests at 29.97/30fps both look a bit strobe-ish but of course "fluid" like 30fps material usually looks.

DPStewart
06-03-2016, 03:27 PM
I think what you think you're seeing is in fact real.

The Nikon showed even more blur than the BMPCC. A smoother blur, but a lot more of it.

THE way to really test this is to shoot the exact same thing with your BMPCC and a brand new BMPCC. Also it would be revealing if you could also get your BMCC back and again shoot the exact same thing.

Sensor readout speed.

Recently a fella posted a comparison of the BMC URSA MINI 4k and the Samsung NX1 4k.
What was most evident was that with just him casually walking into the frame and gently swinging his arms as he walked, the MINI 4k was MUCH clearer. The NX1 blurred his arms even though they were just gently swinging from only a slow normal walking motion.

I don;t know if it's possible for a bad copy of a BMPCC to have 'slower' sensor readout because the software is looking for clock cycles and for everything to be in their expected places in order to execute the code - I'm assuming anyway...

But maybe that IS possible. "Bad copies" have certainly been known to exist.

Hmmm.....

pidulgi
06-03-2016, 04:11 PM
I think what you think you're seeing is in fact real.

The Nikon showed even more blur than the BMPCC. A smoother blur, but a lot more of it.

THE way to really test this is to shoot the exact same thing with your BMPCC and a brand new BMPCC. Also it would be revealing if you could also get your BMCC back and again shoot the exact same thing.

Sensor readout speed.

Recently a fella posted a comparison of the BMC URSA MINI 4k and the Samsung NX1 4k.
What was most evident was that with just him casually walking into the frame and gently swinging his arms as he walked, the MINI 4k was MUCH clearer. The NX1 blurred his arms even though they were just gently swinging from only a slow normal walking motion.

I don;t know if it's possible for a bad copy of a BMPCC to have 'slower' sensor readout because the software is looking for clock cycles and for everything to be in their expected places in order to execute the code - I'm assuming anyway...

But maybe that IS possible. "Bad copies" have certainly been known to exist.

Hmmm.....

Thanks again for the feedback. Indeed at this point the best thing I can possibly do in order to make sure is to rent a working BMPCC and put them side by side. Unfortunately I already shipped out my BMCC. The original owner of this BMPCC made clear he is not up for a refund of any kind bringing every possible excuse to the table. Since it was a local transaction, realistically, I can't force him to meet up. I'm actually impressed that he even replied. After all, I did test the camera during the transaction and I was the one to say okay. Weird shutter was the last thing I was looking for of course.

Nevertheless, this is the last video I can upload at my vimeo at this time. It's a compilation of little clips that I shot immediately after I got the camera. It was those very shots that freaked me out and I started all this research to first see if BMPCC was supposed to do that to begin with. It's not like I'm going to be shooting a lot of panning handheld shots of flowers but if this flickering/strobing in daylight is regarded as the BMPCC shutter's "norm", then I think my understanding of what is the "norm" needs some kind of adjustment. I used the BMCC for a couple of years before I sell it, from the quintessential fooling around test videos up to music videos and other promotional material. Looking at that content with a fresh eye I do indeed observe some kind of judder but the fact alone that it never bothered me pretty much tells me that something's wrong with this BMPCC. As I'm trying to drive some conclusions, I would still appreciate your feedback, on this latest video.


https://vimeo.com/169298036

Howie Roll
06-03-2016, 05:46 PM
It's just judder, it didn't look horrendous on my macbook but looked pretty bad on my TV. Turned on judder reduction and it went away clean as a whip. I think you just started pixel peeping after you saw how lousy the rolling shutter can look on handheld bmpcc footage (which is amplified by judder) and ran with it. There is nothing out of the ordinary here. Good Luck.

pidulgi
06-03-2016, 07:10 PM
UPDATE!

So, first of all, talking about motion and shutters, it was very easy to get confused and mix up some different things into one:
1) the judder - the strobe-like effect where the image seems "jumping" caused by the camera movement
2) the weird motion blur - the lack of proper bluring between the frames

After extensive testing here is the conclusions for number 2:
Captain Hook and anybody else that suggested something is off because of lighting were right. The "ghost" effect with the multiple copies of the objects (such as the finger pictures posted at the beginning of the thread) was indeed caused by the specific LED lights I am currently using in this room. I changed all fluorescent lights of this room into LED just a month ago. I only filmed with this new room lights twice with the BMCC. Looking up that footage as well as older footage and new additional tests concluded 100% that the ghosting doesn't happen in other conditions including daylight.

Number 1:
Judder is a little more complicated as there is no exact definition of what's "appropriate" or "acceptable" judder. Much of the testing content I posted is definitely not the kind of material I would normally shoot anyways. In addition the BMCC was not exactly the camera that I would carry out with me and move around like I did with the BMPCC. So the lack of observing any significant judder might be because I barely shot anything of that kind.

That said, I'm still not sure about number 1. The only true way is to get another pocket and shoot together.

Thank you everybody that contributed their opinions it was very useful to me.
Regardless, please still feel free to write your opinion about the videos, especially the judder.

I hope this experience of mine is useful to anybody else experiencing this problem.

DPStewart
06-03-2016, 07:58 PM
I think this was helpful.

Camera tech and optics are a complicated lot.
Add in strange and unusual new lighting technologies and it gets even more complicated.

FWIW - "Motion Blur" and "judder" can really two be thought of as two different things in today's world of CMOS sensors.

The strobing and blur associated with 24p photography is well established and it's pretty much always exactly the same....PROVIDED you have a global or close-to-global shutter.

ALL "blurring" or "strobing" or judder" is made significantly worse by rolling shutters. The worse the roll, the worse the compounding of the other effects.

Look for any video comparing global shutter to rolling shutter and then look closely at the NOT egregious elements. Ignore the edges of buildings and sign posts etc., and look at the more "normal" aspects of the subjects - like bodies in normal motion. Arms and legs doing just regular every-day movements.
You'll see it... and it ain't pretty.

stip
06-03-2016, 08:32 PM
After extensive testing here is the conclusions for number 2:
Captain Hook and anybody else that suggested something is off because of lighting were right. The "ghost" effect with the multiple copies of the objects (such as the finger pictures posted at the beginning of the thread) was indeed caused by the specific LED lights I am currently using in this room

I had severe 'ghost' effect in daylight too, no artificial lights anywhere. It was so prominent, even the director came asking what's wrong with the motion blur.

DPStewart
06-03-2016, 08:48 PM
I had severe 'ghost' effect in daylight too, no artificial lights anywhere. It was so prominent, even the director came asking what's wrong with the motion blur.

What did you end up doing about it stip?

Did you get rid of the camera, or what?

pidulgi
06-04-2016, 01:59 AM
I had severe 'ghost' effect in daylight too, no artificial lights anywhere. It was so prominent, even the director came asking what's wrong with the motion blur.

I see, then that's something to worry about indeed. In my case I carefully checked the blurring of every object, especially hand movements of all speeds and it was very clear: every time something was under this specific LED lights of my room, both in BMPCC and my old BMCC, there was lack of blur or the "ghosting" effect was there. In any other scenario the blur was normal. I even have some irrelevant lighting tests I did about a couple of weeks ago with the BMPCC in this room when trying to find a nice mix of lights for interviews etc. Every time I added the roof LED lights to the mix for whatever reason (it was a test after all) suddenly motion becomes blurless "echo" or "feedback". When those lights are not part of the setup, the motion blur is normal.

stip
06-04-2016, 05:21 AM
What did you end up doing about it stip?

Did you get rid of the camera, or what?

Can't do anything about it but I still have it. I never understood why and when it occurs. It does however occur more regularly under artificial lighting indeed.
The screen of my pocket also got faulty with time, so I may have a real bad lemon there.

CORRECTION
I may have to correct myself; it could be that that when I had the ghost effect in daylight, big HMI units were hitting the scene. More often than not we use old, non flicker free, ballasts for these. I don't know if that may have caused the ghost motion blur.