First Impression; serious drawbacks

dlpark said:
Here's a link :

http://vimeo.com/20450543

Sorry it looks so compressed, but is this what folks are seeing in the strobe issue ?

dlpark
Click to expand...
Watched that in vimeo, it looked like trash. Watched it full-screen and it looked much, much better. Yes it's strobing like mad, but it's strobing consistently, just like it's supposed to. You can't track that fast and expect it to be smooth, on any 24p/25p footage.

But in Vimeo, it looks wrong. Jerky, start/stop... definitely doesn't look right. On full-screen, it looks just about like I'd expect it to.
 
Barry_Green said:
But in Vimeo, it looks wrong. Jerky, start/stop... definitely doesn't look right. On full-screen, it looks just about like I'd expect it to.
Click to expand...

Yes - Vimeo (streaming) version was so bad I grabbed the source file. On my web browsing machine (Dell XPS laptop) the QT plays OK when 1:1 but awful/jerky when expanded (and QT's normally play fine on this system) so I tested with VLC, MediaPlayer and DivX... all give differing choppy effects.

Agree the slide is fast, but the thing I keep seeing (and even the 1:1 QT shows this) is a very subtle edge break up on high contrast elements. There's something similar going on in another Op's test in another thread...

On this clip it's almost like there's a frame delay on small areas of pixels (keep watching the book/flyer edges and you'll see it eventually) - although it isn't consistent.

Now, I said it reminded me of the way you used to get tape dropout on analogue BetaSP (or HiBand etc) - just a bit of localised dropout that would be such a PITA in the old days. It's not exactly the same... something else it reminds me of is the way you used to get pre-roll on tape machines... just that handful of frames before sync would happen and you'd get a slight bit of something that looks like drop out. But, in these 24P/25P examples, it's like a very localised version of this effect - and only in the high-con areas.

I mentioned in another thread that a good test would be a repeated shot at common frame rates (24/25/30P and 25/30i) just to have a single test bed image to start looking at this. Hopefully someone could do this - as it really needs to be done by an OP that's seeing the problem on their camera all the time (IMO).

Just seems very odd indeed.
 
Barry_Green said:
I'm going to do a sample clip of a constant-speed item that's high-contrast...
Click to expand...

Could this be extended to a duplicate shot in multiple i & P frame rates - if possible (please) :) - as this would also help give a base test for the various 24/25P discussions. Many thanks.
 
Looking at that movie http://vimeo.com/20450543 one can get confused about the ability of the camera to produce sharp wide images and deal with highlights in a proper way. My question to Barry or Jan is: Can this camera comply to the HD 1920x1080 standard and deliver a sharp picture according to this standard? Should one say: it is a 5000$ camera, take it as it is with all the work arrounds?
I'have ordered 3 of this camera's and Iam not so sure anymore.............
 
Watch "A Verse Before Dying". Practically nothing but wides, outdoors in broad daylight. The camera (when used properly) is nothing short of fantastic. Period.
 
Barry_Green said:
I don't think I understand what you're asking...
Click to expand...

Sorry - one test/base shot but with multiple clips in a variety of frame rates (ie giving the result of test_one_24P, test_one_25p etc - advantage is the results would give the answer to what the shot looks like in differing formats - all we see in samples at the moment is a single clip at 25P or 24P) - apols if I was obtuse!
 
Okay, on strobing -- I've uploaded a file. But -- don't just download this and watch it, think about it, because this file was created for specific purposes.

First, I didn't put it on vimeo. This is an uploaded ZIP file of a complete card directory. Download this and play it back on your camera, to an HDTV. Or, pull it into your NLE and look at it frame by frame. I'm trying to eliminate user error, computer recoding, slow graphics cards, and all that other horsehockey out of the scenario and just get down to the brass tacks, which is: does the AF100 sample 25 progressive frames per second properly and play them back properly?

From my perspective, the answer is an obvious "yes". This file is of super-high-contrast black and white lines, passing by the screen and gradually slowing down.

The speed is linear and decelerating, it's a free-spinning turntable that's winding down. I couldn't get the turntable to lock at a low enough speed to show no strobing at all, so I let it run from super-way-too-fast all the way down to stopped. And it behaves exactly as it should. Look at it frame by frame -- there's no weird edge artifacting or whatever else people are talking about, each frame is rendered exactly as it's supposed to be. Yes, at the beginning it strobes like mad, just like film would -- remember the rule, an object should take seven seconds to cross the screen, and these lines are flying past the screen at the rate of maybe 1 second, so of course it strobes. As it slows down the motion looks smoother, just like it should.

Frankly, this is behaving exactly like it's supposed to. I don't see where the problem is?

http://www.mediafire.com/?ncd9eff91996vbv

If you play it back on a computer and you see jerkiness and unevenness in the strobing, it's because of your computer. Play it on the camera, or copy it to an SDHC card and play it on a blu-ray player or PS3.

This footage shows how 25p behaves. If you want it glass smooth and no strobing, you shoot 50p. If you shoot 25p and objects move too fast, it'll be stroby, that's the immutable law of shooting at a low frame rate. These are high-contrast edges and I don't see anything whatsoever that looks out of place (which mirrors Alan Roberts' conclusion after looking into the same issue, where he said "I had a chance, today, to look at a longish AF101 shoot, with lots of motion, on a 50" plasma from very closeup. We had it on a HDCAMSR and could hold and examine frames. No sign of any inter-frame problems at all, everything clean as a whistle ..."

Next time I get some time, I'm planning on doing a side-by-side between the AF100 and a new (to me) Super16 camera, where I'll run them through the same test and hopefully definitively once-and-for-all-in-this-lifetime-and-the-next answer the question of whether the AF100 in 24p mode renders motion the same as film does (hint -- I'm certain that it does). :thumbsup:
 
Clear and objective test!

Imported in FCP7, and looked at it frame by frame, and do not see any strobbing problem (don't have access to a blu-ray / plasma technology at my location... Taiwan)

Thanks Barry
 
Well, where did the thread starter disappear to? People complaining about strobing (with any camera) have always had something else going wrong than the camera. I don't remember any strobing issues that have happened because of a camera.
 
maarek said:
Well, where did the thread starter disappear to? People complaining about strobing (with any camera) have always had something else going wrong than the camera. I don't remember any strobing issues that have happened because of a camera.
Click to expand...

I'm here, been busy working. I still think this is going to be a problem, and as I mentioned earlier, I'm going to shoot some tests next week. FYI I will most likely NOT post the test footage online, because there are too many variables with compression/streaming, etc. But I will post my findings here. If you don't like what I have to say, I apologize. A camera is a tool that I use to do my job, and if it doesn't work for me, I'll find another one.

Barry, you said: Watch "A Verse Before Dying". Practically nothing but wides, outdoors in broad daylight. The camera (when used properly) is nothing short of fantastic. Period.

What do you mean by "when used properly?" Does that mean I can't shoot anything long-lens, high contrast, and with vertical lines? I don't think I can tell my clients that, and that's just not the case with RED, film, Alexa, etc....
 
maxxfish said:
What do you mean by "when used properly?" Does that mean I can't shoot anything long-lens, high contrast, and with vertical lines? I don't think I can tell my clients that, and that's just not the case with RED, film, Alexa, etc....
Click to expand...
Why would you think that? Don't be silly. Obviously you can shoot anything with it. If you want to compare it to a Red (which costs 5x as much) or an Alexa (which costs 14x as much) then yeah, those cameras can do more. But you can absolutely shoot high-quality tele shots with vertical lines and high contrast.
 
maxxfish said:
Barry, you said: Watch "A Verse Before Dying". Practically nothing but wides, outdoors in broad daylight. The camera (when used properly) is nothing short of fantastic. Period.
Click to expand...

Well, of course. But you can get the same fantastic look without having to shoot wides in broad daylight if you know how to properly light/frame.
 
I'm the one who posted the vimeo clip .... dolly along 4H books etc. I was raised a pure shooter. Started shooting commercials for an ABC affiliate with 3/4 SP 22 years ago ! Have shot 16, 35, digiBeta , Beta SP , DV, M2 (anyone remember that ?!!!!) , DVCPRO, and for the past 4 years, P2.....great format ! I'm not surprised that the dolly clip I uploaded looks like trash.
I'm not well versed in Vimeo, compression, codecs, etc.... I'm a shooter. I know I now must learn more to better my craft.
To answer Barry's questions.... no, it didn't look like that when shot or played back through the camera. I shot this :

http://vimeo.com/19305627

in the first 4 days I owned the camera. It's completely ungraded. I've since shot many more projects and am very happy with the results. Since I completely ignored the DSLR revolution, I still feel I have much to learn with the AF100.

dlpark
 
dlpark said:
I'm not surprised that the dolly clip I uploaded looks like trash.
Click to expand...
I hope you know that what I meant was, Vimeo trashed it. Nothing against your shooting skills! Vimeo did something weird to it that added a jerky start/stop pattern in it, which wasn't there in the full-screen version. So, complaining about Vimeo, not you & your skills! :thumbsup:


To answer Barry's questions.... no, it didn't look like that when shot or played back through the camera.
Click to expand...
That's the key thing. If it looks good in the camera and on playback, then that means the footage is good. It now comes down to figuring out how to render that footage to whatever your deliverable format is, but that's all sorts of computer work there... as long as you know the footage is good going in, then you can definitely make a great end product. Not sure what Vimeo did to it, but the source was good, and that's what counts.

I shot this :

http://vimeo.com/19305627

in the first 4 days I owned the camera. It's completely ungraded. I've since shot many more projects and am very happy with the results. Since I completely ignored the DSLR revolution, I still feel I have much to learn with the AF100.
Click to expand...
Saw that when it was first posted, I think you did a great job and your skills with the camera show. You kept all moves to within the 24fps safe speeds, and hey, you even have bright high-contrast vertical lines in there, and it still all looks great.
 
dlpark said:
Here's a link :

http://vimeo.com/20450543

Sorry it looks so compressed, but is this what folks are seeing in the strobe issue ?

dlpark
Click to expand...

I don't think this is what I'd call "strobing"... more like "lag" in which strong verticals are "sliced" in half and the lower part is "delayed" a bit...
This issue is discussed by others who were experiencing the exact issue in the Adobe Premier forum... I found a solution after spending several marathon sessions with the "Outsourced" tech support staff in India.... The link to the thread is here:
http://forums.adobe.com/thread/784071?
In case the link doesn't work, it's entitled "video playback issues" in the "Premier" section of Adobe forums...
I don't think it's so much a camera issue as an edit system problem... at least for me... for a while, I was afraid to pan across vertical subject matter.
 
Thanks for the effort.
However this test only confirms that too fast a movement across the frame causes judder, especially on contrasty verticals.
The whole clip lasts 15 seconds, the last second of which is static (turntable stopped). Skipping this last second and starting from the end when the movement is slowest, we look for the first vertical on the left (the one on the crumpled white) just about to leave the frame --if it wasn't for the fact that the turntable just stopped. We reverse the clip frame by frame. After 112 frames the vertical is to about leave the frame on the right. That's 4.5 seconds, way too fast for safe intraframe movement at 24/25 fps. No wonder that the whole clip judders like crazy . What we need to see is is really slow movement of an object across the frame for more than 7 seconds. My Vimeo clip* has the window vertical border travelling 15 seconds (not 4.5 sec) across the frame, and it still judders. It is not due to coding issues either, because I can assure that it looks exactly the same on the plasma played back from PS3, AF100, in FCP, iMovie, re-wrapped in ClipWrap from .mts into .mov etc etc. In other words double the safe intraframe movement duration (15 seconds and not 7 seconds) still does not prevent judder.
And that is my observation.
I can very well post original files or re-wrapped .mov clips too , except I believe that more independent test are necesseray to confirm or falsify the observation.
Therefore I propose that any new clips subjected to scrutiny be posted at fileservers in both original (.mts) and re-wrappeed (.mov) structures. ClipWrap (divergentmedia.com) is free for the first minute and does excellent job of rewrapping .mts into QT .mov for easy viewing. It does not change the video sample structure at the same time. It is best to watch such clips on a 2010-11 Mac with SnowLeopard/QT X (older machines can stutter).
To me anyway the issue remains unresolved until I'll be able to compare AF100 with our HPX3100, both in 25p mode on the same scene --some time later this month . If they behave the same way it'll mean that AF100 shows the same amount of judder as any broadcast class camera. I'll try to report the findings.

* http://vimeo.com/20429696

PS. If anybody wants the re-wrapped .mov file please PM me for the link.



Barry_Green said:
Okay, on strobing -- I've uploaded a file. But -- don't just download this and watch it, think about it, because this file was created for specific purposes.

First, I didn't put it on vimeo. This is an uploaded ZIP file of a complete card directory. Download this and play it back on your camera, to an HDTV. Or, pull it into your NLE and look at it frame by frame. I'm trying to eliminate user error, computer recoding, slow graphics cards, and all that other horsehockey out of the scenario and just get down to the brass tacks, which is: does the AF100 sample 25 progressive frames per second properly and play them back properly?

From my perspective, the answer is an obvious "yes". This file is of super-high-contrast black and white lines, passing by the screen and gradually slowing down.

The speed is linear and decelerating, it's a free-spinning turntable that's winding down. I couldn't get the turntable to lock at a low enough speed to show no strobing at all, so I let it run from super-way-too-fast all the way down to stopped. And it behaves exactly as it should. Look at it frame by frame -- there's no weird edge artifacting or whatever else people are talking about, each frame is rendered exactly as it's supposed to be. Yes, at the beginning it strobes like mad, just like film would -- remember the rule, an object should take seven seconds to cross the screen, and these lines are flying past the screen at the rate of maybe 1 second, so of course it strobes. As it slows down the motion looks smoother, just like it should.

Frankly, this is behaving exactly like it's supposed to. I don't see where the problem is?

http://www.mediafire.com/?ncd9eff91996vbv

If you play it back on a computer and you see jerkiness and unevenness in the strobing, it's because of your computer. Play it on the camera, or copy it to an SDHC card and play it on a blu-ray player or PS3.

This footage shows how 25p behaves. If you want it glass smooth and no strobing, you shoot 50p. If you shoot 25p and objects move too fast, it'll be stroby, that's the immutable law of shooting at a low frame rate. These are high-contrast edges and I don't see anything whatsoever that looks out of place (which mirrors Alan Roberts' conclusion after looking into the same issue, where he said "I had a chance, today, to look at a longish AF101 shoot, with lots of motion, on a 50" plasma from very closeup. We had it on a HDCAMSR and could hold and examine frames. No sign of any inter-frame problems at all, everything clean as a whistle ..."

Next time I get some time, I'm planning on doing a side-by-side between the AF100 and a new (to me) Super16 camera, where I'll run them through the same test and hopefully definitively once-and-for-all-in-this-lifetime-and-the-next answer the question of whether the AF100 in 24p mode renders motion the same as film does (hint -- I'm certain that it does). :thumbsup:
Click to expand...
 
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