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-   -   What about "real" Rolling Shutter problems ? (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/123747-what-about-real-rolling-shutter-problems.html)

Peter Rixner June 14th, 2008 09:56 AM

What about "real" Rolling Shutter problems ?
 
Hi :)

i am very interested in EX1 und EX3 but still be very concerned about the rolling shutter problems.
But what I really wonder:
Everything I can find on the web (especially EX1) is always some concern about flashlights, stoboscopes, police car flashes and so on.

All of that doesn't scare me as much as skew when panning. For some reason I cannot figure out, that is rarely tested with EX1.

So can someone give me some informations on that please ?

Thanks!

Peter

Bill Ravens June 14th, 2008 10:58 AM

If you pan fast, you will see skew. IMHO, if you pan fast enough to induce skew, you 're panning too fast to care anyway. 24 fps requires a very slow pan. 30 fps requires a very slow pan to not get long GOP pan artifacts. If you pan slowly enough to avoid these artifacts, you'll never notice the rolling shutter skew.

Moving objects within the frame are an entirely different matter. Usually motion blur will mitigate the skew effects. If you shoot at high shutter speeds, with high motion within the frame, skew will be most apparent.

Tom Roper June 14th, 2008 01:21 PM

The EX1 in my early judgment, merits judicious care in a number of potential areas, panning and shake yes, but also white balance, knee, focus and simply not inadvertently tripping one of its many switches found all over the body. It's fairly demanding, especially 24p. I wouldn't even think about not using a tripod in that mode. For handheld fastwork, it has some advanced automation controls (TLCS), I'm not decided whether the auto-focus is trustworthy or not.

Surprisingly, one of the many justifiable complaints has in my case been a blessing. The cursed handheld ergonomics actually suit me like a fish takes to water, due to my prefererence to use the LEFT eye with the viewfinder. I have rotated the rubber eye cup 180 degrees. That puts the whole cam in a much more ergonomic handheld position for me, with my left hand supporting the cam underneath, fingers on the dials.

I wish peaking worked in the expanded focus mode.

Bob Grant June 14th, 2008 05:41 PM

The worst / only problem I've had with the rolling shutter is with lights running at oddball frequencies. They appear as waves of light on walls. It's almost a pretty cool effect unless those lights are the only lighting source, then you get rolling bars which is definately not a cool effect.
Nothing unique to the EX1, any camera with a rolling shutter exhibits this problem.

Buck Forester June 14th, 2008 06:40 PM

This was a big concern of mine too as I spent gazillions of hours researching which camera to get. What I saw posted in forums was extreme cases, and I just figured all footage under those circumstances would show this trait. Then I saw lots and lots of EX1 footage online and found that people are shooting pans very successfully when they know what they're doing and the proper settings are used. I've also noted, as someone said above, to achieve the rolling shutter requires fast pans that I would find unwatchable with any camera.

Tim Polster June 15th, 2008 07:41 AM

Hey Everybody,

I would like to ask about the flash strobe effects with the EX-1/3.

My concerns are the opposite. The motion seems fine to me but what scares my is the cameras reaction to camera flashes and strobing lights.

What if you are shooting a wedding and the photog is shooting a lot?

What if you are shooting a live concert/event and people in the audience are shooting flashes or the stage lighting has a strobe effect for an entire number?

If EX users could please chime in with some real world experience I would really appreciate your input.

The situations I mention here can not be fixed by adding a few white frames as the footage would have a lot of flash involvement and if the camera did not handle the scene, you would be high and dry.

Thanks

Sebastien Thomas June 15th, 2008 08:17 AM

Quote:

Originally Posted by Bill Ravens (Post 893041)
If you pan fast, you will see skew. IMHO, if you pan fast enough to induce skew, you 're panning too fast to care anyway. 24 fps requires a very slow pan. 30 fps requires a very slow pan to not get long GOP pan artifacts. If you pan slowly enough to avoid these artifacts, you'll never notice the rolling shutter skew.

Moving objects within the frame are an entirely different matter. Usually motion blur will mitigate the skew effects. If you shoot at high shutter speeds, with high motion within the frame, skew will be most apparent.

I also had the skew effect this the EX1 fixed on a harm fixed to the top of a car. The goal was to shoot the driver/passenger from the outside of the car, while moving, without a travelling car.
The road was old and I ended up with shaky footage.
On some, you see the rolling shutter distortion.

another guy on the list also had problem while shooting from a helicopter.

Just be carefull of fast shake.

Peter Rixner June 15th, 2008 11:45 AM

Thank You all so far.

So after all that I think I'll have to wait until technology improves.
Should I say to clients: Sorry, no flashlights, flashing concert lights or shaky shots ? :)

I think it's just too dangerous to get into shooting situations that you cannot handle and haven't the time to change the conditions.

What I really wondered is that on a test in a different, german forum - which I am not registered at - they shoot a spinnig wheel that shows fields (which means it's moving) but none of that serious rolling shutter artifacts I have seen on the web.

http://www.slashcam.de/artikel/Test/...y-PMW-EX3.html

That lets me doubt again the other way around ...

More comments are very welcome for further building an opinion ...

Thanks!

Peter

Craig Seeman June 15th, 2008 12:08 PM

EVERY camera, even the most expensive have advantages and disadvantages and caveats. That's why people will chose one camera over another given the specific circumstances.

The only time I've seen rolling shutter in a USEFUL shot is when panning to follow a fast moving subject. The subject looks fine but background objects do skew. Does anyone show concern over the background skewing? In every case people are focused on the subject so the answer is no. Of course your clients and needs may be different.

I have shot fireworks on a few occasions. I've never seen partial (rolling shutter) flashes. I've have certainly seen them on other people's video with camera flashes. It seems to occur when the flash fills the screen and happen at such speed that the sensor is not completely scanned in that time frame. Yes that can probably happen when standing next to a photographer using a flash that completes faster than the EX1 sensor is scanned. Sometimes clients may see it as "different" but not necessarily bad. Again depends on your client.

You'll have to weigh the above regarding frequency of occurrence and possible client reaction vs the control of depth of field, resolution, other features the camera offers and the fact that my clients now get a "look" they could not afford otherwise.

You could always choose to use a Panasonic HVX 200 (or new variants) but you have to weigh its features against the EX1/3 as a package. I'm not going to rehash that here but for example if you're doing event work around photographers:

Compare low light noise vs rolling shutter issue and decide which would bother your client more.
Compare SxS record duration and offload speed to "other."

Waiting until technology catches up has to be compared to living with the additional disadvantages of your current kit. No one can answer that but you but that's a comparison you'll have to make as a business and/or creative person.

Serena Steuart June 15th, 2008 09:14 PM

You should never decide on the basis of forum postings; these are to be regarded as "advisory" -- notification of matters to be assessed. Hire a camera and test. You may decide that your application needs a CCD camera. But what is the effect of someone firing off a flash? In a film camera that frame is way over exposed. Same with CCD. A rolling shutter can give you a bright band across the frame, the same frame that would be ruined on a CCD. The fix in post is to treat that frame, which is a nuisance and may be more work than you consider worthwhile. Filming under strobing light is a problem anyway.

Mike Williams June 15th, 2008 10:37 PM

I'm with Tom Roper on this one. The cam is great but is demanding. I have owned the cam a few months now and I have rarely put it on a tripod. The cam is amazing and you just need to rent one, do some tests for yourself. Cam shake is cam shake. I have yet to have any issue with this.

I haven't really noticed any issues with photog flashes that are better/worse than the Z1.

As Serna says don't judge completely by posts. I read some people saying the EX was just OK in low light and I find that completely contrary to my experience. I still don't like the transfer software etc, but wouldn't give up my EX for anything at this point.

Matt Davis June 16th, 2008 01:02 PM

Quote:

Originally Posted by Peter Rixner (Post 893414)
That lets me doubt again the other way around ... More comments are very welcome for further building an opinion ...

I shoot corporate events - often working beside a photographer. On a recent job, I wish I could get the time to do an edit that demonstrates that the EX1 can do HD handheld with a photographer in the room, and that switching the shutter off doesn't turn the picture to mush (I'll supply a URL to the client-approved edit if you wish). But be assured that the rolling shutter issues, whilst DEFINITELY something to know about, aren't necessarily worth writing home about once you've made your peace with this remarkable camera.

If you're on a tripod on a long lens, kicking the tripod (a task usually delegated to a passer-by) will make the image shimmy as if in heat haze. If you pan the camera past rows of vertical objects, you will see them lean, but it's not exactly the sort of shot I want to go out and shoot. Switching on the shutter cures many of these things, but flashes can get truncated, BUT if the photographer is shooting with flash, light is usually low, and I'd prefer to switch the shutter off and get an extra stop.

It took a month to learn to trust the camera. I went from triumph in first ownership to a pit of doom as I waded through back-focus issues and misunderstanding the EX1 modus operandi. I survived a couple of shoots - and yet, clients commented (positively!) on the quality of images. I've got DoF, painterly tones, great colour, sharp images, and I don't worry about flash or leaning lines because Dark = Shutter OFF, and leaning lines just don't figure in day-to-day shooting for me.

Wait if you wish. My EX1 is fully employed. In my line of work, the EX1 is great and I want to add an EX3 soon.

Anyway... what I actually wanted to post was this:

http://www.masters-of-fine-art-photo...rtigue_01.html

A famous shot quite simply made brilliant by an almost century old Rolling Shutter!

Dave Morrison June 16th, 2008 01:16 PM

I've been LOOKING for that car shot for days to illustrate the effect that everyone here is so worked up about. Good find, Matt.

Peter Rixner June 16th, 2008 02:33 PM

Thanks. I really appreciate more and more opinions.

Regarding that old phtograph:
Only that things had been bad (and were better with CCDs) doesn't make that picture good :)

I suppose with the next (not so far - If I look at the time distance between EX1 and EX3) generation of CMOS Cameras these bad effects will soon become less. And so I think I'll join You CMOS guys next spring :)

But still ... Please more opinions. I am still not a 100% CCD-man :)

Peter

Matt Davis June 16th, 2008 02:54 PM

Quote:

Originally Posted by Peter Rixner (Post 894012)
Regarding that old phtograph:
Only that things had been bad (and were better with CCDs) doesn't make that picture good :)

Maybe I didn't quite understand your response, but note that Jaques Henri Lartigue is my photographic hero.

That picture is good on so many levels...

... And your smiley is the only thing between this and a flame.

JHL captured this shot and found that the panning and the progressive shutter added a dynamism UKNOWN before the invention of the progressive shutter. This is a photograph untouched by Photoshop. Heck, John Knoll's grandparents were probably frolicking in the hay when this was taken.

This is not a distorted shot, it is a photograph that is full of a new view of reality. Look at other shots of JHL - Edwardians captured in 'Kodak' moments before Eastman had really got the Brownie under way.

This shot epitomizes how a technical effect is exploited to communicate speed, brute force, dynamism, the awe of the spectators, the thrill of the moment...

...and oops, sorry, I've turned into my tutor. Sorry. It's still a brilliant shot though.

Bottom line: if that's how it works, work with it, not against it. IMHO.


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