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-   -   HV20 Impressions -- HDMI etc. (https://www.dvinfo.net/forum/canon-vixia-series-avchd-hdv-camcorders/89578-hv20-impressions-hdmi-etc.html)

Robert Ducon March 26th, 2007 11:57 AM

Quote:

Originally Posted by Heinz Bihlmeir (Post 646075)
There remains also the question, is the final output sampled in 4:2:2 or 4:2:0. Analysis of the captured frames may answer these questions.

If it's 4:2:0, and captured with component, isn't there a chance there will be lag on the chroma side and we might see a ghost trail or such (just of the chroma?) That might be a giveaway. Not sure.

Anyone have ideas how to tell 4:2:2 from 4:2:0 on captured footage? 4:2:0 should be "half" of 4:2:2 in some regard, right?

Mike Brown March 27th, 2007 07:20 AM

Quote:

(2) When zooming in aufofocus mode, the camera gets out of focus
and then becomes sharp again continously.
This sounds like the same issue addressed in another thread titled "Returning HV20 After One Hour." After several pages of discussion, a consensus seemed to develop that the original post was based on unrealistic expectations. But Heinz Bihlmeir has made a similar observation.

Now I'm really confused. Does the HV20 focus-hunt during zooming more than other camcorders? Is it a defect, or should one just accept that autofocus must be turned off during zooming? More feedback on this subject would be appreciated.

Alan Dunkel March 27th, 2007 08:17 AM

The auto focus is fine
 
Mike, The default instant auto focus us just that, way fast, in this case calling it instant isn't much of a stretch. If the center of the image is small, like a squirrel, it will hunt if the camera person is shaky with the camera or the squirrel moves, not so with a larger subject or a steady hand. It is a very useful auto foucs feature, you can even simulate a rack focus with it, it snaps to that fast, it is unlike any other auto focus I've used and a great tool. I did change mine to regular ( not instant ) in the menu and it works like any consumer auto focus. I've been using that setting, but when going with manual focus I set back to the instant mode and can go to that or manual quickly that way without the menu. To each his own, but there are no issues with HV20 focus. None at all, now like any auto focus when you get in low light performance of the auto focus degrades, I'd suggest going manual and using the focus assist on the LCD when lighting dims. The HV20 image does do well in lower light, at least in 24p mode, which took me by surprise. I'm in no way saying it is a night vision device, you need light, but it does well in that regard for a basic consumer camera. My plan is to use an external monitor for narrative work, but that is due to the addition of the Brevis35 on front and a Nikon 50mm. In that configuration I will focus using a 720p monitor, not needed for the camera on its own though.
Thanks, Alan

Alan Dunkel March 27th, 2007 08:26 AM

The auto focus is fine
 
..just waiting for my Brevis35.

Heinz Bihlmeir March 27th, 2007 12:00 PM

1 Attachment(s)
Quote:

Originally Posted by Mike Brown (Post 649334)
Does the HV20 focus-hunt during zooming more than other camcorders? Is it a defect, or should one just accept that autofocus must be turned off during zooming? More feedback on this subject would be appreciated.

Here there,

maybe its a fault of my Japanese HV20 with an early firmware revision , but I can easy replicate the described effect. If anyone is interested I can upload a video made in auto mode, which shows the effect. It doesn't disqualify the quality of the auto focus system in general, but there seems to be a certain condition (lighting, scene content, distance etc) in which the closed loop of the AF system becomes slightly instable. The four images in the attachement are consecutive frames (24p) from a record during zoom.

Heinz

PS: I love the camera and I can live with this problem.

Ken Ross March 27th, 2007 02:01 PM

Quote:

Originally Posted by Mike Brown (Post 649334)
This sounds like the same issue addressed in another thread titled "Returning HV20 After One Hour." After several pages of discussion, a consensus seemed to develop that the original post was based on unrealistic expectations. But Heinz Bihlmeir has made a similar observation.

Now I'm really confused. Does the HV20 focus-hunt during zooming more than other camcorders? Is it a defect, or should one just accept that autofocus must be turned off during zooming? More feedback on this subject would be appreciated.

No Mike, in fact it hunts far far less than any other camcorder I've ever used...sans the HV10. There appear to be only two reports of this with the HV20 and everyone else is having no issues. I don't know why people will always focus on 1 or 2 reports when there are so many others that report no issues. We don't know if 1 or 2 cameras were defective, if the user was unaware of how to use the camera or some other issue. But the bottom line is if this is such a tiny % of the total users, it's obviously not a design issue.

Ken Ross March 27th, 2007 02:06 PM

Heinz, I would suspect it's some aspect of an early firmware version. It seems that you and only one other person reported this issue. Everyone else is having no problems. I compared mine with my HV10 quite extensively and it simply never missed when zooming at full zoom or full wide angle. It was every bit as superb as the HV10.

Pieter Jongerius March 27th, 2007 03:30 PM

Hi Ken,

there is another. ;)

Joe Busch also reported it:
http://www.dvinfo.net/conf/showthrea...508#post647508

Now i'm sure this is something I will be able to live with (as in be annoyed with when it happens but getting over it because of the rest of the package is so good).

If I'm not mistaken my (currently dead) Optura 100MC also had trouble focussing while zooming. I solved that by zooming in first, locking focus, then zooming out for the beginning of the shot, and zooming in slowly during the shot while keeping focus locked.

Colin Gould March 27th, 2007 05:13 PM

I'm unclear how the HV20 w/ identical optics/OIS would have focus problems in zoom, that the HV10 didn't (apparently) have.?
Shouldn't the camera stay in focus all during a zoom in/out, once focus is set? (old trick to focus at full telephoto, then zoom out for wide w/ focus locked, so when you go to closeup during the shot you don't get hunting)

The only issue I have w/ zoom & focus on the HV10 is that at far telephoto for relatively near (5-10') objects, it goes (and stays) out of focus (but as tipped here, I should stay wide and use macro-style instead).

Ken Ross March 27th, 2007 06:32 PM

Quote:

Originally Posted by Pieter Jongerius (Post 649642)
Hi Ken,

there is another. ;)

Joe Busch also reported it:
http://www.dvinfo.net/conf/showthrea...508#post647508

Now i'm sure this is something I will be able to live with (as in be annoyed with when it happens but getting over it because of the rest of the package is so good).

If I'm not mistaken my (currently dead) Optura 100MC also had trouble focussing while zooming. I solved that by zooming in first, locking focus, then zooming out for the beginning of the shot, and zooming in slowly during the shot while keeping focus locked.

Pieter, the original thread starter has since exchanged her first HV20 for another unit and she reports it works perfectly. She says the zoom & focus are now perfect. So that one was unquestionably defective. I still think this represents a tiny % of the total units out there. But we can say with 100% certainty this is not a design issue. If it were, virtually all units would exhibit the same behavior. Also keep in mind that the design of the Instant Autofocus is entirely different than what was used in the Optura.

Colin, you are correct, there is NO difference in the design of the Instant Autofocus in the HV10 & HV20. They both work perfectly, but there may have been a couple of problematic units. I see absolutely no difference whatsoever between the Instant Autofocus during zooming of my HV10 & HV20. They both work great.

The procedure you described is a manual focus procedure, but is generally unnecessary if you want to use autofocus. An exception might be during low light, shooting through glass or something unusual in the field of view.

Pieter Jongerius March 28th, 2007 04:00 PM

Hi Ken,

Quote:

Originally Posted by Ken Ross (Post 649752)
Pieter, the original thread starter has since exchanged her first HV20 for another unit and she reports it works perfectly. She says the zoom & focus are now perfect. ...

Great, didn't catch that post. That /is/ good news.
Thanks,
Pieter

Michael Barrette March 28th, 2007 08:33 PM

I tried out an HV20 in a store yesterday and actually taped some of the footage and took it home....

The one I tried definitely had focus challenges when zooming. Especially when the scene had more than one object in it. It basically was not useable footage when zooming. That's what I found anyway. It did work for simple focus where the object it is focusing on is the only thing in the picture. That being said, it's dirt cheap and something that can learn to be lived with....

Ken Ross March 29th, 2007 08:57 AM

Quote:

Originally Posted by Michael Barrette (Post 650455)
I tried out an HV20 in a store yesterday and actually taped some of the footage and took it home....

The one I tried definitely had focus challenges when zooming. Especially when the scene had more than one object in it. It basically was not useable footage when zooming. That's what I found anyway. It did work for simple focus where the object it is focusing on is the only thing in the picture. That being said, it's dirt cheap and something that can learn to be lived with....


Mike, it's quite possible that there was an issue with that unit. I can tell you that most people and reviews are finding this to be the best autofocus in any camcorder. The original poster thought there was a problem too until she got her new one. She now raves about it. :)

Mike Horrigan March 29th, 2007 09:01 AM

Quote:

Originally Posted by Michael Barrette (Post 650455)
I tried out an HV20 in a store yesterday and actually taped some of the footage and took it home....

The one I tried definitely had focus challenges when zooming. Especially when the scene had more than one object in it. It basically was not useable footage when zooming. That's what I found anyway. It did work for simple focus where the object it is focusing on is the only thing in the picture. That being said, it's dirt cheap and something that can learn to be lived with....

What store in Canada did you find it in??

Please get back!

Mike

Ali Husain March 31st, 2007 05:16 PM

thanks for doing that test! it makes sense since, in a static scene, only the color resolution is different between hdv and hdmi, correct?


Quote:

Originally Posted by Heinz Bihlmeir (Post 648534)
@Pieter

I don't think that the real output resolution captured from the HDMI output is better than HDV. There are of course compression side effects, depending of image content and motion in the scene.

I have captured and analyzed a resolution chart using HDMI and HDV and compared the results, they are quite simular (see attachment).

The optical system (lens, focus etc.) is also limiting the bandwidth.

Regards
Heinz



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