Hi, Now that the HV30 is here (and it isn't $1400), I am very close to buying this camera.

Except one thing really worried me about it having read through som many internet boards like this over the last year (regarding HV20).

I'm talking about what became known as the "wobbly" effect, and a posted clip shot froma helicopter is the one that really bothered me.

Can anyone verify that the effect is NOT common to the camera, or at least verify that it occurs mostly at 24p.

If I was to take footage from a chopper at 60i I would be OK?

I do know why the effect comes about and read about the "rolling shutter" etc. Just want some peace of mind about it if possible!

Rolling shutter in an inherent feature of modern CMOS sensors.
http://www.vimeo.com/746718 -- pay attention to 2:50-3:30
http://www.youtube.com/watch?v=rfCjkDFgb2s -- pay attention to video made with in-car camera

The rolling shutter skew is a factor of the angular momentum of the image being recorded with CMOS sensors. How many degrees you swing the camera in a given amount of time. In other words, panning slower will reduce the problem. Going more wide angle will reduce the problem. You want to reduce the speed of the image passing through the frame. Shutter speed and frame rate will also affect the image.

You might read Stu Maschwitz's brief comment on his blog, http://prolost.blogspot.com/2007/05...ng-shutter.html.

There are a lot of doomsayers regarding rolling shutter skew. If it matters to anybody, it would not be a dealbreaker for me in regards to the HV20 or HV30. Most people don't notice it unless it is pointed out. You might go to

http://vimeo.com/videos/search:hv20...ormat:thumbnail

which has about 500 HV20 videos's. See for yourself what the video looks like.



Rich

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Thanks for the info.

Please note I am not concerned about something that is subtle. Its just that the helicopter footage we saw a while back (I THINK it was in 24p) from HV20 was absolutely horrific. I was hoping to hear if someone has had an OK experience with the HV20 or 30 in a helicopter, or could at least verify that 60i in a chopper would be OK.

And yes, I'm not going to be in a chopper that much but it was one heck of a test seeing that old footage. The whole thing looked like jello and was pretty scary.

Right, Vimeo has a lot of examples of rolling shutter, from pretty cool ones like this http://www.vimeo.com/604275 to disgusting like this http://www.vimeo.com/901788 to really horrible like this http://www.vimeo.com/819044 or this http://www.vimeo.com/920276.

Many modern cameras, even professional ones, have CMOS sensor, so you don't really get to choose if you want a specific make and model.

Thanks for those links. The bent coin thing is very cool, and the bad stuff is really bad!!

Can someone please verify, that the bad examples of Rolling Shutter (where you would NOT want it), occur only in 24P mode. And even then , OIS needs to be OFF?

I wonder what the car driving scenes etc look like in 60i or 24P OIS ON? Any guesses?

Seems you don't get it. Rolling shutter is a feature of a CMOS sensor, all CMOS sensors (at least all sensors in consumer cameras) behave this way. The effect produced by rolling shutter does not depend on frame rate or shutter speed, though these settings can affect the way how the resulting video looks like.

I do not think you went through the sites I referenced in my previous post.

There has been some great footage shot with the HV20 and HV30. It seems you are focusing on the bad parts, not the good parts. The rolling shutter is a problem with all camcorders which have CMOS sensors. Perhaps you should consider a camcorder with CCD's instead of CMOS sensors.




Rich

I have gone through various sites, please understand I am not slamming the camera. The footage is wonderful (usually) and there is no denying these are the best cameras out there for the price.

But also understand that as a potential new HD camera user, seeing that footage that is taken from the car(s) is scary. Thanks for clarifying that this is what can be expected of any CMOS camera, and I did need the extra clarification that this has nothing to do with frame rate and - or OIS being on or off.

I think it's important, if I do understand this correctly now, that this and any CMOS camera can't be used from a car or helicopter etc. For just about everything else it's wonderful, and I really want one, but isn't this an important point to be made for any camcorder customer?

Yes I mistakenly thought the really bad examples of the wobbly effect were only in 24P mode and or OIS off etc. I guess I was hoping if I was in 60i or something other than 24p with OIS etc I could occasionally shoot from a moving car, for example.

I guess that manufacturers do not expect regular consumers to shoot from helicopters or race cars Check out this video

http://www.youtube.com/watch?v=rfCjkDFgb2s

it is a British TV show, see shots from within the cabin, for example at 3:13-3:16, 3:29-3:32, etc. You can see the same effect. Looks pretty bad for a professional broadcast show. They limited these pieces to just couple of seconds and with all the noise and vibration most casual viewers won't notice the "wobbly" effect.
OIS helps if you shoot handheld (have you seen the one with the Sony SR11, shot for a French video magazine? Handheld with max zoom and OIS off looks as bad as from a helicopter, but with OIS on looks ok).

I will be honest, I do not have a High Definition camcorder.

I have edited several hours of HDV and a few minutes of AVCHD.

If I had to buy a camcorder today on short notice it would be the Canon HV30 unless I had a special requirement.

I have been playing with "video" on and off since about 1969.

You keep talking about "scary" footage with no reference. I have enough experience with camcorders to create some scary/bad footage...

I said "The rolling shutter is a problem with all camcorders which have CMOS sensors." but I should have qualified that different models and different shooting conditions/situations can have different effects. Frame rate, shutter speed, speed of the target and panning speed are major factors which create the problem as well as the model of the camcorder. Here is a nice video shot with the Sony HDR-HC3 and Canon HV20. Both camcorders have CMOS sensors: http://www.vimeo.com/481411

I have several hundred hours in a helicopter as a passenger/crewman and about 400 hours as a Pivot Pilot. There will be more problems shooting from those conditions than just "Rolling Shutter".

You are expecting everything to be perfect. Come back in 50 years, it still won't be perfect, but you will have gained some wisdom. I have been saying for many years "Any video is better than no video".

Once again you keep talking about bad video which I can't see. So I really can't comment. At this point I really don't want to see it anyway.

Look at these two video's from Ian-T. He did a good job. From moving car's, at night. It's skill more than anything else: http://www.vimeo.com/user318567

Rich

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Hi Poncho, thanks for hanging in there with me for a minute about this. You were saying I haven't offered a reference, this one actually comes from a vide jockey quoted above:

http://www.vimeo.com/819044

And that is the type of video I had been seeing posted on the internet. It's not a race car or fast helicopter, it's simply engine vibration rendering the video un-usable. Please note this is where I was coming from: someone turns on a car engine, it's not even moving, and the picture looks like jello. That's a big concern not for just film makers, but tourists and your average camcorder user who might be in a car or bus at some point etc.

However, you recommended I look at this one:

http://www.vimeo.com/user318567

and it looks GREAT!!!

This is why I was wondering about settings. One video, the car isn't even moving and it looks absolutely horrific. The other video the car is moving and the video, to me, looks fantastic. So...is it settings?


(I do understand rolling shutter is CMOS....but why do these two videos look so completely different?).

Thank you for your patience...

The first video is shot with OIS off, the second is shot with OIS on. The cars are different too, so the vibrations are different. OIS can help to diminish or even to remove the effect. It does not ALWAYS help, but it does help often. It is somewhat sad that you don't get this sort of effect from a $200 camera with a single CCD sensor, but you can get other effects from CCD, like light flare in form of a vertical bright line.

Every technology has its good and bad sides. Most likely you won't ever come across this effect, but I agree that manufacturers should clearly explain in layman terms to an average Joe what kind of artifacts to expect, from interlacing to macroblocking to optical distortions to rolling shutter effect.

I would understand if the built-in electronics were smarter than an average human and were bulletprooff and were consistently delivering better results than in a manual mode, but it is not as good yet, and manufacturers have to teach consumers about positives and negatives of their products. Instead they hide the negatives and push the positives, sometimes even falsify the product information, like Canon claimed that the HG10 records in full 1920x1080 while it is not.

Nothing wrong with recording in 1440x1080 or having specific effects of a specific implementation of technology, but this should be truthfully explained to a consumer. I suppose there is no law that obliges manufacturers to do that.

So, the only way to make an informed decision is to educate yourself. It is easier now than 20 years ago, the Net has tons of information, sometimes contradicting, but if you care about what you are buying it is worth spending a couple of days or even a week on research. After all, it is fun, at least for me. I was choosing my HDTV for almost two months. I was choosing my first camcorder for almost a month. I am still choosing my second camcorder ;-)

It is setting's, techniques and what vibrations are you really dealing with? The video you referenced said "High frequency engine vibrations". What the heck is that?

There is no magic formula and answer for every situation but shooting from cars by itself is a problem. Shooting video by hand can be a problem. OIS and EIS is not a magic fix. If you can't stabilize a camcorder properly you will have crappy video.

I don't know what your expecting...



Rich

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Thanks for the responses.

What am I expecting? Well, it's really simple. I'm actually what I think could be classed as a typical consumer customer...lots of touristy stuff and some occasional creative use. As a tourist, I'm often in a moving vehicle, car, train, whatever, and sometimes though not often in a helicopter.

Looking at the videos I'm not sure what to expect when in a moving vehicle, it's really that simple I guess. The bad examples of the effect are important to note, because how often does a tourist go into a helicopter? Not often, and it's really expensive. But when a tourist does, he wants to know the camera can take some footage. Not expecting miracles in terms of stability, it's just that some of the examples could easily lend one to believe that any footage from a chopper or moving vehicle will be completely un-usable.

Poncho, you did post however an example taken from a moving car that turned out great. It's really as simple as that...can I take holiday footage from a vehicle? Looks like sometimes yes and sometimes no.

So, this isn't a feature film making question, more of a tourist one...yes moving vehicle shots are often crappy, but when you're there, you've got to at least try some footage especially if you've forked out the money for a helicopter or small plane joy-ride. I'm new to CMOS, so if it can't take what my CCD cameras can, I just at least need to know when I can use it and when I can't, to avoid those extreme effects.

Don't mean to tie you up with this, thanks for your responses again. The links you've posted are very useful.