Rolling Shutter

[Vaughan Wood]

I haven't seen any information that says whether the camera has a rolling shutter or global shutter technology.

Has anyone seen anything?

Vaughan

[Mark Utley]

On this note, could someone explain the difference? I've heard about rolling shutter issues but don't know how it works.

[Vaughan Wood]

There's plenty of info about it on the web, basically my non-technical blurb is... on a rolling shutter, the information is fed through from top to bottom of the chip, so there is a slight delay in refreshing the data.

For high shutter speeds or fast motion shots, or in my particular gripe - photographer's flashes, this results in bending of straight lines, or "interrupted" photographer's flash.

I believe global shutter can eliminate the problem, probably reading from different points at once, but I'm guessing here.

Time for the greater knowledge prophets to jump in!

Cheers Vaughan

[Alister Chapman]

Were going to try to take a look at this here at IBC.

[Vaughan Wood]

Thanks Alister.

Just get your mate to take your photo! (LOL).

As an added thought, was Sony's press conference videod.

Been looking on the net but nothing!

Vaughan

[Barry Green]

I haven't seen any information that says whether the camera has a rolling shutter or global shutter technology

It is rolling shutter, and it does have some "wobble." Mikko Wilson's reporting live from the IBC show floor and filed some notes to that effect on ibc.mikkowilson.com. If you have specific questions you want answered, you can send him a text message and he'll try to get to the right people and ask it and post the results on his news feed.

[Brian Cassar]

Can you kindly explain what is a "wobble" please? I'm used to the shoulder camcorders and have no idea what this is. I have read in this tread, I believe, that rolling shutter causes problems with flash from photographers. How bad is the effect?

Thanks

[Alex Leith]

Depending on how slow the "roll" is on the rolling shutter, things can look pretty ugly - objects can appear "bent" (especially things with circular motions - like wind turbines), photographer camera flashes and lightning can cause bright strips to divide the image.

[Barry Green]

Wobble has been discussed extensively on the web. It's something new; you wouldn't have experienced it on a shoulder-mount camera before because all the shoulder-mount cams used CCD or tube sensors. The rolling shutter is unique to CMOS camcorders.

Search around here for "wobble", especially in the HV20 forum, and you'll find all you care to read about on it.

The extent of the EX1's susceptibility to wobble isn't yet known; Mikko's report said that there was "slight wobble".

[Ali Husain]

flash problems? lol. on a camera with really bad rolling shutter issues--one that takes say 1/48th sec. to scan a frame--global motion is distorted quite hideously. i'm thinking of the canon hv20 here. if you have to move the WHOLE camera with an imager like this, then you have a problem.

a steadi-cam will alleviate it quite a bit: you won't notice the distortion easily because it ramps in slower with the steadicams reduced acceleration. if you jerk/suddenly accelerate the camera by shooting handheld, the sudden distortions will be obvious... the scene will look jelly-like. if you're not moving the whole camera, even on a camera like the hv20, you probably won't notice it.

i believe red and si-2k both have rolling shutters. i think theyr'e just much faster than the one on the hv20. my bet is the sony is similarly faster.

as an aside, if you're new to rolling shutters, know that the speed at which the roll occurs is not necessarily tied to the speed at which each horizontal line is exposed--the latter being the "shutter speed" that you normally think about.

[Alister Chapman]

I shot some footage out of the window of a moving train with the EX1 and the passing trees looked OK. I will try to shoot some pans and flash guns today. When I get home I will take a closer look at my EX footage.