5D canon Mark II

[Yan Clement]

Hello !

 

There was this fashion show going on close to my house and decided to test my new 5D canon mark II video capabilities... and discover huge rolling shutter or shutter speed problem when other people in the crowd uses flash for picture !? Don't know what it is ?

 

1. Rollling shutter

 

2. cmos refreshing speed ?

 

3. Shutter speed ? here i was using 1/ 40

 

4. Camera problem ?

 

here it is on youtube.com

 

http://www.youtube.com/watch?v=of24qSNHL9g

 

1 / 40 T 2.8

800 ASA

 

Yan Clément

yanclement@gmail.com

514.796.6596

Edited February 12, 2010 by Yan Clement

[Yan Clement]

I need help to find out if this is a problem in the camera or something else ? Thank you !

[James Brown]

I need help to find out if this is a problem in the camera or something else ? Thank you !

Hi -

 

It's hard to tell whats going on in the image. Have you put it through any other tests? Maybe some simple tungsten lighting effects flashing a pup on and off and see if it is a similar degradation of the image. . We shot some concert stuff at Falls Festival of the 5d & 7d with pretty full on lighting effects and didn't see any of the problems you have here.

 

Regards, James

[Yan Clement]

Ya I did some test with flashing light tungsten but it's when flash are strinking... Did you shoot with flash poping in the show you filmed ? The problem look like if the refreshing time of the cmos is not fast enought .. and you see that the image is taken interlaced ?

 

 

 

Hi -

 

It's hard to tell whats going on in the image. Have you put it through any other tests? Maybe some simple tungsten lighting effects flashing a pup on and off and see if it is a similar degradation of the image. . We shot some concert stuff at Falls Festival of the 5d & 7d with pretty full on lighting effects and didn't see any of the problems you have here.

 

Regards, James

[John Brawley]

Hello !

 

There was this fashion show going on close to my house and decided to test my new 5D canon mark II video capabilities... and discover huge rolling shutter or shutter speed problem when other people in the crowd uses flash for picture !? Don't know what it is ?

 

Your problem is that you have a 5D and are using it shoot video and expecting it to be perfect.

 

Sorry.

 

**Just to add. Flash always cause this kind of problem on cameras that have rolling shutters. There's nothing wrong with your camera.

 

jb

[Tom Mitchell]

Ya I did some test with flashing light tungsten but it's when flash are strinking... Did you shoot with flash poping in the show you filmed ? The problem look like if the refreshing time of the cmos is not fast enought .. and you see that the image is taken interlaced ?

 

Ok this is a rolling shutter issue the reason you get it with a flash and not a tungston bulb. Is the flash starts and finnish before a single fram of the camera is exposed. a tunston bulb will take a while too cool down and will expose for at least a fram if not more, and the rate in whitch it dims it far more gradual and less far less noticeable.

 

The camera downloads from the chip a line at a time from top to bottom over say 1/30th of a second or 1/24 of shooting at 24fps. the flash fires much faster, So it causes banding where part of the image is exposed from the flash, and the flash has gone out before it reaches the bottom of the chip.

 

Film cameras suffer form this because they have a spining shutter. And RED as well as many other digital cameras have this issue, though it by far worst in the cannon. this is a common issue and there's no real get around. remember it's a stills camera at the end of the day and thats what it's primary designed to do, so it's not going to be a master at video. it's still dam good. it's a shame they use a video codex to record to that is considered to be a delivery codex there so much information lost in the image because of that, but i digress.

 

Ajusting shutter speed doesn't get rid of the problem but some times it can help, though you effecting the motion sharpness of each frame and the further you go from a 180 degree (thats 1/60th at 30fps) shutter ther less 'normal' it will look.

 

in short your cameras not broken but there's not much you can do about it ether. The saving grace is that 99% of the average joe watching it wont even notate.....especially with that subject matter:p

[Yan Clement]

well thank you !!

 

How'about pixel... There one pixel that show up in red ? Is this normal too ?

 

 

Your problem is that you have a 5D and are using it shoot video and expecting it to be perfect.

 

Sorry.

 

**Just to add. Flash always cause this kind of problem on cameras that have rolling shutters. There's nothing wrong with your camera.

 

jb

[Tom Mitchell]

well thank you !!

 

How'about pixel... There one pixel that show up in red ? Is this normal too ?

 

Ok i didn't notice the first time I watched it but, i didn't watch at full rez or at full screen my bad.

 

I now see it in the right third of the screen half way down.

 

No that's not normal, at the worst case it could be a dead pixel, in that case refer to your warranty.

 

Try giving the sensor a clean, it could be just some dirt or dust, both using the camera self clean, and failing that get a sensor cleaning kit and give it a clean. make sure you read up on how to do this properly or you could damage the sensor.

 

I don't know if the camera has a black balance feature but run that too see if that makes a difference.

 

also I seen damage to sensor from lasers, though the tend to take out several pixels at a time, though i'm no suggesting this is the cause, pixels do just die sometimes but just useful to know when your in a night club etc. we lost a red sensor to a laser the damage, we knew the about it at the time but the powers at be chose to risk it. It tends to look like a dotted line across in the path the laser hit the sensor (its dotted because the laser swtiches on and off at a high frequency)

 

I hope that is of some help

[Yan Clement]

Well Tom thank you very much... It's bad issue but like you said what can we do! Anyhow it does take crazy video too ! I'll check for the cleaning sensor thing... I look up and there is a function in the camera that is supposed to reset those red bastard ! Thank you !

 

Yan

 

Ok i didn't notice the first time I watched it but, i didn't watch at full rez or at full screen my bad.

 

I now see it in the right third of the screen half way down.

 

No that's not normal, at the worst case it could be a dead pixel, in that case refer to your warranty.

 

Try giving the sensor a clean, it could be just some dirt or dust, both using the camera self clean, and failing that get a sensor cleaning kit and give it a clean. make sure you read up on how to do this properly or you could damage the sensor.

 

I don't know if the camera has a black balance feature but run that too see if that makes a difference.

 

also I seen damage to sensor from lasers, though the tend to take out several pixels at a time, though i'm no suggesting this is the cause, pixels do just die sometimes but just useful to know when your in a night club etc. we lost a red sensor to a laser the damage, we knew the about it at the time but the powers at be chose to risk it. It tends to look like a dotted line across in the path the laser hit the sensor (its dotted because the laser swtiches on and off at a high frequency)

 

I hope that is of some help