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Canon XH Series HDV Camcorders
Canon XH G1S / G1 (with SDI), Canon XH A1S / A1 (without SDI).


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Old September 13th, 2007, 12:12 PM   #16
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are these final, rendered clips or artifacts that you see on the timeline? i though i had a serious issue as well but discovered that wasn't the case after exporting. i see it only in editing, when vegas stretches the 1440 to simulate device aspect ratio. when rendered, monitored, or reviewed from in-camera the footage looks fine. here's before and after.
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25F - stairs in thin objects-no-render.jpg   25F - stairs in thin objects-rend.jpg  

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Old September 13th, 2007, 02:31 PM   #17
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Originally Posted by Brandon Freeman View Post
I can see the stair-stepping in 24f, to answer an earlier question. Not terrible, though, I find it to be very faint, only noticeable on contrasty edges, and if you go down to 1280x720, it's gone.
Thanks for your answer. I'm quite sure now that this is what is happening also in my case. FCP is not to blame.
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Originally Posted by Eric Weiss
are these final, rendered clips or artifacts that you see on the timeline? i though i had a serious issue as well but discovered that wasn't the case after exporting. i see it only in editing, when vegas stretches the 1440 to simulate device aspect ratio. when rendered, monitored, or reviewed from in-camera the footage looks fine. here's before and after.
Now that I've made some test more, I can confirm that I see those same stairs in all steps (in camera, imported clip, timeline, rendered).

And again, stairs are visible in very few shots / situations. Otherwise 25F-mode looks just great.
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Old September 13th, 2007, 05:45 PM   #18
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Originally Posted by Poppe Johansson View Post
Now that I've made some test more, I can confirm that I see those same stairs in all steps (in camera, imported clip, timeline, rendered).

And again, stairs are visible in very few shots / situations. Otherwise 25F-mode looks just great.
I couldn't get your clip open, but I believe you. Well that's a bummer. I guess I won't be using the 25p mode if I get an xh a1.
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Old September 13th, 2007, 08:50 PM   #19
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The good news is that while the stepping artifacts can sometimes show up under some circumstances, they're generally not visible when watching the video on a TV set. Virtually all of these more affordable camcorders fall short in some area when scrutinized closely. But play it back on an HD TV and voila; beautiful video.

I know I've had people over to watch some 24F footage on my 42" TV and they've always been stunned by how awesome it looks. Are there some shots with jaggies in there? I'd bet on it. Anyone notice them? Nope.
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Old September 14th, 2007, 01:36 AM   #20
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The good news is that while the stepping artifacts can sometimes show up under some circumstances, they're generally not visible when watching the video on a TV set. Virtually all of these more affordable camcorders fall short in some area when scrutinized closely. But play it back on an HD TV and voila; beautiful video. I know I've had people over to watch some 24F footage on my 42" TV and they've always been stunned by how awesome it looks. Are there some shots with jaggies in there? I'd bet on it. Anyone notice them? Nope.
I've been watching "these stairs" all the time via HDTV, my 2nd monitor is 40" Full HD TV, so stairs are there, but you're absolute right that I do look the picture much more careful than people who just watch the contents.

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I couldn't get your clip open, but I believe you. Well that's a bummer. I guess I won't be using the 25p mode if I get an xh a1.
It's not that bad. The reason why I see it is that I shoot mainly nature. There are just lot of hard situations for 25F (and also for mpeg2). I just watched 3 hours of 25F material and (visible) stairs were only in couple of shots.
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Old September 14th, 2007, 04:33 AM   #21
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Does the xh a1 encode 25p material better is it has less information than 50i? Does it look better encoding wise?
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Old September 14th, 2007, 09:28 AM   #22
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I would say no, but I'm not really sure about that, because it does look different, even if the picture has no moving objects. Is it encoding difference, don't know.
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Old September 14th, 2007, 10:17 AM   #23
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Originally Posted by Poppe Johansson View Post
I've been watching "these stairs" all the time via HDTV, my 2nd monitor is 40" Full HD TV, so stairs are there, but you're absolute right that I do look the picture much more careful than people who just watch the contents.
Well that's a bummer. If the stepping is enough where its bothering you while viewing on a TV, you might try a horizontal channel blur. Sometimes just blurring a single channel by a pixel or two does a nice job of reducing some jaggies without appreciably softening the image. It ain't perfect, but it can help sometimes.
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Old September 17th, 2007, 01:14 PM   #24
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Originally Posted by Poppe Johansson View Post
I get quite bad stairs in thin lines [in 25F]. But I haven't ever seen this with 50i.
Can you post samples of the same scene shot in 25F and 50i?

What is your sharpness setting? Having it too high will certainly cause stairs. Does turning it all the way down make a difference?
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Old September 17th, 2007, 01:46 PM   #25
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Perhaps the JPG algorithm is causing such a severe stair stepping. What program are you using to make you're jpegs? What is the quality setting for the JPEG?

Do you have screen caps off a high resolution hot screen we can see to compare the level of stair stepping? Is the stair stepping even there in a full rez hot cap with biometric compensation?
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Old September 17th, 2007, 01:55 PM   #26
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Perhaps the JPG algorithm is causing such a severe stair stepping. What program are you using to make you're jpegs? What is the quality setting for the JPEG? Do you have screen caps off a high resolution hot screen we can see to compare the level of stair stepping? Is the stair stepping even there in a full rez hot cap with biometric compensation?
http://aavekammari.pp.fi/stairs.mov

There is an original FCP captured file (HDV Quicktime 1080i50, 25Mb). This has nothing to do with jpeg. It's there in the original file also and when viewed directly from cam.
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Old September 17th, 2007, 01:58 PM   #27
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Can you post samples of the same scene shot in 25F and 50i?What is your sharpness setting? Having it too high will certainly cause stairs. Does turning it all the way down make a difference?
I'm going to be very busy in coming weeks, but I'll try to create an example (25F/50i) as soon as possible.
My sharpness setting is set -1. I haven't test it yet, but I'm quite sure that turning it down will decrease stairs. Of course this would also make all shots too soft. I have to try this also in real life when I have more time.

As I earlier wrote, stairs are visible in very few shots.
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Old September 18th, 2007, 04:52 AM   #28
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Still can't open that file, can you give a straight m2t file without any encodes to a different format?
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Old September 18th, 2007, 06:40 AM   #29
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You need a QuickTime Pro to view FCP HDV files. I made H.264 clip. Of course it isn't the original anymore.. but at least you should be able to watch it.
http://aavekammari.pp.fi/stairs2.mov (8Mb)
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Old September 18th, 2007, 04:01 PM   #30
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I had some stairs in my footage too.
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