Left and Right of Picture Quiver on Zoom

Michael H. Stevens · April 8th, 2008, 10:05 PM

EX1 is shooting 1920x1080x24p at 1/48th second. Fully manual mode - no AF/MF or auto exposure - full manual. When I zoom in - I have the handle zoom set to 50 - while the center third of the screen is fine, the two outer thirds of the screen shake left to right like a quiver. The shaking width is only about 5-7 pixels and the effect viewing on a big screen from a distance is the left and right sides of the screen appear to pulsate. Focus remains sharp, it is just a shaking issue.

Mike

Matt Davis · April 9th, 2008, 12:57 AM

Just conjecture, but perhaps a byproduct of CMOS rolling shutter?

Michael Mann · April 9th, 2008, 01:14 AM

Michael, can you post a demo clip?

Alexander Kubalsky · April 9th, 2008, 08:26 AM

Working in 1080p24 a while back I was doing some slow zoom outs on a friends artwork against a white gallery wall. When I transferred and played it back on my macbook pro as a mov. file it seemed to kinda step as it zoomed out. By that I mean when you look at the edges of the painting as the camera zooms out the borders don't shrink fluidly as you would expect. It has a slight stepping effect as it gets smaller.

I thought it might be that my mac couldn't keep up with playing such a large file smoothly or the rocker zoom is not so touch sensitive on slow zooms as it should be. I took the original file into my dealer and played it on a Panasonic Monitor and it looked much smoother. So a macbook graphics card thing?

I had the camera in to sony recently (particles inside lens) and thought I'd ask them to check the zoom as well anyway. They checked and said the zoom control was fine but that 30p is recommended for slow zooms. So its a fps thing?

Somebody on a forum today said it could be an auto focus thing. I may have had it on auto focus but I cant remember. I think a higher shutter speed would actually help smooth it out. Im going to do some more tests when I get a chance, different shutter speeds, zoom speeds, and auto focus on, off, the works.

A few people have had this issue and I was thinking might be a good idea for anyone with a zoom step issue to share short original files to check. I sent the above mentioned file to a friend through skype the other day and he said it played fine on his PC (he's a gamer so would have a pretty good setup)

Skype anyone? My skype name is alexkubalsky.

Michael H. Stevens · April 9th, 2008, 09:29 AM

Alex, thanks. But don't forget that while my edges did what you describe, my center was OK. Check your problem file to see if your center was fine too. Also note I am not playing from a computer. This is the final rendered version played from a Blu-ray disk from a Blu-ray player to a big screen TV.

April 8th, 2008, 10:05 PM	#1
Michael H. Stevens Major Player Join Date: Sep 2007 Location: Palm Desert, California Posts: 311	Left and Right of Picture Quiver on Zoom - Center OK EX1 is shooting 1920x1080x24p at 1/48th second. Fully manual mode - no AF/MF or auto exposure - full manual. When I zoom in - I have the handle zoom set to 50 - while the center third of the screen is fine, the two outer thirds of the screen shake left to right like a quiver. The shaking width is only about 5-7 pixels and the effect viewing on a big screen from a distance is the left and right sides of the screen appear to pulsate. Focus remains sharp, it is just a shaking issue. Mike

April 9th, 2008, 01:14 AM	#3
Michael Mann Major Player Join Date: Dec 2005 Location: Kelkheim, Germany Posts: 375	Michael, can you post a demo clip? __________________ Michael

April 9th, 2008, 08:26 AM	#4
Alexander Kubalsky Regular Crew Join Date: Jan 2008 Location: Japan Posts: 172	skype share anyone? Working in 1080p24 a while back I was doing some slow zoom outs on a friends artwork against a white gallery wall. When I transferred and played it back on my macbook pro as a mov. file it seemed to kinda step as it zoomed out. By that I mean when you look at the edges of the painting as the camera zooms out the borders don't shrink fluidly as you would expect. It has a slight stepping effect as it gets smaller. I thought it might be that my mac couldn't keep up with playing such a large file smoothly or the rocker zoom is not so touch sensitive on slow zooms as it should be. I took the original file into my dealer and played it on a Panasonic Monitor and it looked much smoother. So a macbook graphics card thing? I had the camera in to sony recently (particles inside lens) and thought I'd ask them to check the zoom as well anyway. They checked and said the zoom control was fine but that 30p is recommended for slow zooms. So its a fps thing? Somebody on a forum today said it could be an auto focus thing. I may have had it on auto focus but I cant remember. I think a higher shutter speed would actually help smooth it out. Im going to do some more tests when I get a chance, different shutter speeds, zoom speeds, and auto focus on, off, the works. A few people have had this issue and I was thinking might be a good idea for anyone with a zoom step issue to share short original files to check. I sent the above mentioned file to a friend through skype the other day and he said it played fine on his PC (he's a gamer so would have a pretty good setup) Skype anyone? My skype name is alexkubalsky.

April 9th, 2008, 12:57 AM	#2
Matt Davis Trustee Join Date: Aug 2005 Location: Berkshire, UK Posts: 1,562	Just conjecture, but perhaps a byproduct of CMOS rolling shutter?

April 9th, 2008, 09:29 AM	#5
Michael H. Stevens Major Player Join Date: Sep 2007 Location: Palm Desert, California Posts: 311	Alex, thanks. But don't forget that while my edges did what you describe, my center was OK. Check your problem file to see if your center was fine too. Also note I am not playing from a computer. This is the final rendered version played from a Blu-ray disk from a Blu-ray player to a big screen TV.