'Rolling shutter' on 3-CMOS chip cams?

[Dan Robinson]

In light of the known issue with the tendency of the A1 / HC1 CMOS sensor exhibiting the 'rolling shutter' effect (the one that results in slanting of fast-moving objects and the difficulty of capturing fast subjects like lightning strikes), is it yet known if this will be an issue with the new 3-chip CMOS cameras?

[Steve Mullen]

Haven't seen it in 4 hours of video.

[Wolfgang Winne]

FX7 rolling shutter:

www.fxsupport.de/fx.mpg [36 MB, MPG2, SD PAL]

(original HDV, Shutter 10.000 - 25)


This article describes the differences between the rolling shutter used in CMOS sensors and the frame (a.k.a. global) shutter used in CCD sensors:
http://www.ptgrey.com/support/kb/index.asp?a=4&q=115

[Ken Ross]

Originally Posted by Steve Mullen

Haven't seen it in 4 hours of video.

Makes two of us Steve.

[Douglas Spotted Eagle]

That's because it's exceptionally rare that folks are shooting at very high shutter rates.
Sorta like someone buying a Ford Explorer and taking it onto an Indy track.
"The tires wobble at 200mph when on a banked curve and cold track."
Well...yes they do. Most any truck will, because it's not built to be optimal at that speed in those conditions. A vehicle that will manage those conditions costs significantly more.

Anyone owning any other camcorder can find all the faults and display them. Or, they can recognize what a tremendous value they have in their hands and work with it. I still own my HV10 even though I can't use it for my desired application. I'm very happy with it. I just know I can't jump from an aircraft nor mount it to a motorcycle. That's OK by me, once I know the limitation, I'm happy to avoid it.

[Tony Tremble]

In all the years of shooting professionally and for fun have I ever shot at such a high shutter speed as to show rolling shutter on these cams.

These sort of things really only are problems for the typical internet crowd who'll jump on something and blow it out of context. Yeah, we all shoot fan blades rotating for a living. :)

TT

[Wolfgang Winne]

http://web.tiscali.it/rudiversal/ima...fekt%20HC1.JPG

effekt in the typical video....


in the fx.mpg is the shutter from 10.000 down to 25, the effekt is in all shuttertime!

[Ken Ross]

I must be blind because I've never noticed this effect with my HC1, HC3, HV10, FX1 or FX7. If the issue is noticeable at all shutter speeds, there must be a lot of people out there besides me that are also blind.

[Wolfgang Winne]

<I must be blind because I've never noticed this effect with my HC1, HC3, HV10, FX1 or FX7.>

the Fx1 is CCD, no rolling shutter.....

[Ken Ross]

True Wolfgand, but what about the HC3 & FX7....they're both CMOS. I don't dispute the issue, I'm just saying most people rarely see it if ever. I'd rather concentrate on issues that are more common and prevelant in typical videos.

[Wolfgang Winne]

This effect is in each CMOS HDV camera. For most videomaker is this effect without problems, problems gives it however with 3 or 4 point tracking in the post-software (digital Fusion).

[Tony Tremble]

If you are going to label rolling shutter a problem then you need to quantify that problem.

The idea that still image without any notes of camera speed or shutter speed can be used as an exemplar of the problems is deeply flawed. Anyone can pick an extreme situation to prove their point but it is not indicative of a problem overall.

All I can derive from the information posted if you want to measurebate by shooting an office fan then you might get better results by using a camera with CCDs rather than CMOS chip.

The rolling shutter effect should only be seen in exceptionally fast camera moves and when exceptionally fast objects are shot at atypical shutter speeds.

TT

[Wolfgang Winne]

<The rolling shutter effect should only be seen in exceptionally fast camera moves and when exceptionally fast objects are shot at atypical shutter speeds.>

That is not correct. This effect is with each shutter (10.000 or 200), see that in the fx.mpg. This effect is released by each fast object or with handcamera...

[Tony Tremble]

Originally Posted by Wolfgang Winne

<The rolling shutter effect should only be seen in exceptionally fast camera moves and when exceptionally fast objects are shot at atypical shutter speeds.>

That is not correct. This effect is with each shutter (10.000 or 200), see that in the fx.mpg. This effect is released by each fast object or with handcamera...

You've just proven my point. I don't actually think the 200 - 10,000ms are typical shutter speeds and shooting an office fan is something that most people wouldn't do! In reality you will not find too many objects travelling as fast as the blades of a fan through the frame in the course of typical usage. So what does that set up prove?

I think you are trying to find a problem where there is none.

If you consider the rolling shutter a problem then buy/use another camera. Don't unfairly portray the camera by using an unrepresentative situation as it is not fair on the people interested in owning this fantastic camera. You could sway someone to purchase another camera when they would otherwise be more happy with the FX7/V1. The rolling shutter effect has to be put into context of how people use and what they shoot in the real world.

TT

[Ken Ross]

Tony is right on the mark! ;)