The difference in PQ between JVC GY-HMZ1 and GS-TD1

I have both, but I haven't done any serious A/B comparisons. The TD1 is a great camcorder, especially in 34mbps mp4 mode. Still, now that I have it I much prefer to shoot with the HMZ1 at 24p. Editing and exporting 60i footage can be a royal pain. Blu-ray 3D supports 720/60i or 1080/24p, but not 1080/60i. AVCHD 2.0 might seem to offer a solution, but as a "standard" it's a mess right now. If your editing needs are very, very simple, the MediaBrowser software that ships with the JVC can create great looking discs, but if you plan to do serious editing, you'll make your life much easier by shooting with the HMZ1 and editing in Edius 6.5. Progressive footage compresses more cleanly than interlaced, and motion resolution should be better, too (with the typical low frame rate caveats, of course). If your goal is to end up with the highest quality 1920x1080/24p Blu-ray 3D disc, the HMZ1 is the better choice.

That is true. But we are not talking about more light, but we are talking about resolution. The interlaced video is degraded in quality due to interline flicker, that is something that cannot be avoided at all - not even for static footage.

For s3D the additional question is what will be the final format. If it is 1080 24p for profile 5 3D Blu-ray, you will loose additional quality due to the new calculation of every frame.

Actually, if you mean blurry pictures as "worse" at slower shutter speeds, that is normal behavior from an exposure to movement perspective. That is traditional photographic science and easy to explain.

OK, I understand and apologies for underestimating your photo knowledge.

Never saw that sort of artifact either. Check with Joe Clark as he has much experience with that camcorder. You have some problem going on there.

I can't say that I've ever noticed anything like what you're describing. When you get it uploaded, I'll be happy to take a look.

The JVC is a real pleasure to use. The only significant problem I've had with it is a general over-saturation, especially with red. But it's easily tamable with color correction controls in Vegas or Edius. As for editing interlaced footage in Vegas, it's easy. Vegas does a very good job de-interlacing 1080/60i 3D footage to Blu-ray 3D at 1080p/24. If it didn't, a lot of hard work on my part would have been wasted. I edit in Edius 6.5 and export the video to Vegas for rendering to Blu-ray 3D at 1080p/24. I find Edius' 3D controls quite good, but I try to avoid using them whenever possible by setting convergence for each shot. OTOH, the JVC's auto control does a really good job of keeping convergence manageable. When I start using the Steadicam rig this spring (and when I'm shooting with the JVC), I plan to use auto convergence most of the time for those shots.

Earlier versions of Sony Vegas didn't de-interlace well at all for some of my footage, so I started using a plug-in. Version 11 improved that performance dramatically. I think it works well now. I haven't tried VirtualDub or AviSynth.

The final release of Edius made significant improvements in a lot of areas, so if you can you should try it again. Playback performance, especially, is far better. Edius is smooth as silk compared to Vegas on my system (overclocked Intel i7 3930). In general, I also like Edius' auto convergence feature for my JVC footage. Plus, Grass Valley supports just about every kind of footage you throw at it, and they have no bias against JVC as Sony does. I didn't mind converting all my footage too much in the beginning, but now that I'm used to simply dropping any clip into the timeline, I won't go back. Using both Edius and Vegas together in my workflow is a lot better than splitting JVC files manually, re-pairing them in Vegas and then suffering through choppy playback when the timeline gets even a little bit more complicated.

You're perfectly right about the JVC's auto convergence feature causing edge violations. They're absolutely unavoidable if you don't set parallax manually. You're in good company when you describe this as "intolerable," but it's a philosophical position that not everyone shares. James Cameron puts it this way, "There is no screen." Quite simply, this sums it up for me in terms of how I "tolerate" edge violations. Most of the time (with a few obvious exceptions), they just don't bother me. My brain doesn't have a problem with them. If you count James Cameron and the producers of just about every Imax film (especially the earlier ones), and Martin Scorsese, you also find yourself in some pretty good company if you think edge violations are OK. In fact, Cameron argues that "the edge violation rule" should be broken as frequently as possible. He believes it's critical for 3D storytelling, at least the way he does it. I'm no expert in this area, but based on my limited experience, I agree. I've decided not to let edge violations determine whether a shot is usable or not. Some of my favorite shots are ones where the TD1 dynamically adjusted the parallax. If I try to "fix" it in post, the shots do become unusable, usually because of extreme background divergence. Many of my favorite 2D shooting techniques are lost to me if I let edge violations rule how I shoot 3D.

YMMV.

The deinterlacer in Vegas is still not as good as it could be - that is one reason why it makes still sense to use special applications like Tempgenc, for stepls like downsizing of HD-footage to SD-footage for a SD-DVD. What has been improved is the capability to render 1080 60i to 1080 24p, what is remarkable that this has become better - a lot of people are satisfied with that now, even if I for my part do still not like the rendering from 1080 50i to 1080 24p.

For edge violations at the left or right side you can use floating windows. At the bottom the are less critical. But I think we still have to be carefull here about the stress that we put in the video - not everybody has become s3D stress resistant like us, trained by sitting at the editing computer.

Yes, if you're careful not to pan too fast, Vegas does a very respectable job of de-interlacing 60i to 24p now. At least that's my experience.

I have lots of shots with edge violations that floating windows won't fix. For instance, one thing I always liked to do when shooting 2D was use a tree or other plants to frame a distant object. It was a way of adding "dimension" to flat shots before real 3D. I still like to do that, even when shooting 3D. For instance, I place the camera so that I get part of the trunk of the tree, and an overhanging branch, to frame a bridge in the background. This works great in 2D, but depending on the distances, it can cause edge violations in 3D. If I'm close and I manually converge on the tree trunk, the bridge spacing (left/right views) in the background is too wide. I might not have a problem watching such a shot in 3D, but many people would. On a large screen, it might not be possible for some people to converge the bridge at all, and it would likely cause headaches in many. So, is that shot unusable? If you believe that edge violations shouldn't be allowed, yes. I'd have to frame the shot entirely differently, or not use it at all. However, the JVC's auto parallax control adjusts the 3D spacing so that the middle ground becomes the point of convergence for that shot. This reduces the left/right spacing of close and distant objects, but it creates an edge violation in which the tree trunk extends into space in front of the monitor, The edge of the screen bisects the trunk. The good thing is that neither the foreground object nor the background object is so widely spaced as to cause viewing discomfort.

Remember Cameron's first rule of 3D - there is no screen. For him, the fact that the tree protrudes out of the monitor is not a problem. He says that the only time this is a concern is when you do the 3D gag in which an object moves straight out of the background and toward the viewers' eyes. Then, the edge violation calls attention to itself and shouldn't be used. Consider "Avatar." Cameron moves his cameras all over the place, in and around trees and bushes, through doorways in the labs, etc. Edge violations are everywhere in Avatar, and if you watch what happens in any given scene, you see that the way he shoots makes eliminating them all but impossible. Most Imax films pay no attention to this "rule," either. And look at many current 3D releases, including Scorsese's "Hugo" or "Open Season" (the animated film voiced by Debra Messing and Ashton Kutcher). Even in animation, where avoiding edge violations is easier, many filmmakers just don't do it.

Generally speaking, edge violations in the periphery of my vision (at the frame edges) don't bother me. They don't cause my brain to reject the 3D-ness of the shot. I've decided that trying to eliminate them is not worth the cost. For moving shots, it's clear to me that you either use them or you scale back motion so dramatically that you cripple yourself creatively. And if you make that exception for moving shots, it's easy to make it for many static shots, too. If it works for one type, and doesn't confuse your brain or your viewers', it's not a "rule" you have to follow. That's my take on it.

Joe, my point is simple: if you like to put stress on the audience, then there is no need to care about edge violations. Then there is no need to care about the maximum disparity as defined by the average eye distance. Then you can run popouts without any limitations.

But if you care about the stereoscopic stress, then you will be more carefull.

To my opinion, there are two directions within s3D: the one that cares and the one that does not care really. I prefere to be on the more careful or conservative side. But that is up to everybodys own decision, up to everybodys own responsibility.

Wolfgang,

IMO, those are two very different things. One means caring about people's comfort and the other means caring about a rule. I don't think most edge violations cause any sort of physical or mental "stress" in the vast majority of viewers. I'd argue that most will not even be aware of them or care in the slightest that they "break the rule." Large amounts of divergence of objects within the stereo frame, however, will cause many viewers discomfort, whether or not they understand why they're getting headaches or eye fatigue. Allowing some edge violations in your productions allows you to frame your shots more freely and creatively. It's also likely to reduce maximum disparity and the chance that your viewers will experience eye strain. That means caring more about people and the creative process. If you mean to say that I care less about the rules, then I agree. The "rules" don't matter much to me. Rules are made to be broken, and as more and more people shoot 3D, the majority seem quite willing to change the rules. One new rule seems to be that edge violations are secondary to creative and effective storytelling. That's a rule I can get behind, and I choose not to worry about the old, more restrictive one.

I know this is a subject of fierce debate among those who create stereo images, both still and moving, so we're not going to resolve it here. I hope we can still be friends.

BTW, I'm not saying that I don't work hard to eliminate some edge violations. For medium shots and especially close ups, I often don't want them, so I crop and scale until they're gone, or I discard the shot. I don't know exactly where my "cutoff" point is for being comfortable with edge violations. I just "feel" whether it works for a given shot.

To my opinion, rules derive in most case experiences - means that people have learned something about s3D and came up with something what they named a "rule". I do not care so much about the rule, and sure they are not un-breakable. But I care about the experience behind those rules.

Sure, edge violations may put less stress on the audience then other errors - like a huge disparity that harms the fusion in the brain to a s3D picture. Or a huge difference in the height of L and R. But for sure an edge violation is an error since it breaks the s3D effect too - at the edges. The issue with that is, that people will react in a different way to different errors. Even without knowing what is wrong, some will react with headaches, others will not. The individual level, where somebody goes into discomfort, is very different.

From that side I tend to go into a more conservative approach, trying to minimize the stress elements where I can. And for sure it should not be in a way where we substitute one minor stress element (edge violation) with another one that is a no-go (disparity > 6.5 cm). In the end it is the combination of the settings we have to choose, to end up with a minor stress level - for example, shooting with parallel axis allows to reduce disparities. Floating windows will allow to correct some footage without increasing the disparity. Stayin without the minimum distance will allow us to keep disparties low, even in the near point or far point. That are elements that may help to minimize stress.

I am aware that it is a little bit borring if you move everything to a positive parallax. The objects look more away compared to a setting where you have also some negative parallax in the movie. A conservative editing uses that approach - conservative thta tries to minimize stress. Other editings accept a higher stress level. Whatever is better is a hard decision - and I am not sure if there can be a general answer to that. For sure, a production where >70% of the audience ends up with headache has done something wrong.

I think that is no question of friends (we are friends) but more on what we will generate with our productions. I think it is also a question of responsibility we have here.

Sure, moving everything behind the zero plane will generate a "more perfect" windows, where you look into the garden - and everything is perfect. Beside one small issue: the objects appears in more distance. That is something that takes you a little bit more "out of the happening" - what seems to be more an issue at smaller screens at home. That is what I meant with "a little bit more borring". I also tend to move everything toward positiv parallax, in my videos.

The "friends" comment was a joke. If I let philosophical differences get in the way, I'd lose half my "political" friends.

Philosophically, we obviously have some differences of opinion, but in practice I doubt we're that far apart in how we approach 3D. I tend to push most things back behind the screen plane, too. It's just that I've decided to go ahead and use some of those early shots I did before I even knew what edge violations were. And when faced with the question of whether to take a shot or not because of an edge violation, it won't bother me to get that shot. When I can avoid them, I do. When I start doing a lot more Steadicam work this spring, I suspect I'll feel even more inclined not to worry about such things. The more you move the camera, the more edge violations are going to happen.

Maybe my brain works differently, because most of the time edge violations don't make me feel like objects are being cut by the screen frame. My brain "puts them" where they belong. Then again, I'm one of the lucky ones. I can deal with tremendous disparity that would give some people migraines. I've never had a headache because of 3D, even anaglyph, which causes me the most physical "distress" of any type of 3D I've seen.

I have to run now, but I'll take a look at the videos later.

I have been composing more projects lately with 2D stills shot with my NEX 5n. Here I prefer to add the 3D effect and push the still shot back behind the screen frame as that looks more natural to me than up in front. When I do this it keeps the s3D mind frame flowing for me especially if I also add a bit of movement to the still, by panning or zoom. If I leave the still photo static and at the screen, it is jarring to the video story with video clips.

I guess it looks more natural behind the screen plane because distant scenery always tends toward flatness anyway. If I sit the still 2D shot in front up close, the flatness of it is jarring.

I'm not sure what's going on technically, but I think the white dots are a result of the camera's auto exposure system causing mpeg artifacting. In some situations, I've noticed that fine details, even in static images, distort from frame to frame. It looks to me like the camera is trying to adjust for proper exposure, and the lower the shutter speed the less able it is to accurately capture details. I've never shot test patterns, but I've seen this sort of thing happen with real world footage.

Your 60i shots do appear sharper than 24p. How were the patterns lit, and did you have all the camera settings on manual? What did you use to capture the stills from the video?

I wish the original Blu-ray 3D spec had included 1080/60i. There's no doubt in my mind that it looks better on all my displays than 1080/24p that's been converted from 60i. As Wolfgang notes, the conversion software has to create 24 entirely new frames every second. 60i looks cleaner and has smoother motion. Of course, the Blu-ray spec does not include 1080/60i, so if you want your productions to be able to play on any Blu-ray 3D player, you have to convert to 1080/24p or 720/60p (in NTSC land, of course). Either way, you lose something in the translation. That's one of the reasons that shooting at 24p makes life so much easier. Since I'm not shooting Nascar or horse racing, it works well for me. I just wish the software wouldn't insist on re-sampling to a lower bit rate, too. Is it too much to ask to maintain the original quality of the footage? Apparently, it is, because that's what you're forced to do with JVC footage shot at the highest bit rate.