What bothers me about 24F
Is this going to be the first & last run of cams with 24F?
In other words are these cams, even though they just came out, kinda obsolete because there imaging will never be used again Does the 24F & 24P edit together with no problem? Will the rest of the industry abandon "F" mode support? Don't get me wrong I'm a Canon guy. Just want my investments to stand up to the changes in tech. as long as possible. |
It is not the first run with 24F. The first run with 24F was the XL H1, introduced back in September 2005. I'm not sure what you mean by "their imaging will never be used again." Can you state that in a different way?
24F *is* 24P. 24F is captured into a computer with an NLE application such as Final Cut Pro, Adobe Premiere Pro etc. as 24P. So yes, you can edit it together with 24P from a non-Canon camcorder with no problem (although if you mix video together from two different kinds of camcorders, your biggest issue will be matching their color and tone, sharpness, etc.). I don't think you need to worry about the rest of the industry "abandoning" 24F support. All of the major NLE applications are fully compatible with Frame mode (Avid being the most significant exception). Canon is one of the top four camcorder manufacturers in the world, with a significant market share in this industry, so I think it's safe to assume that Frame mode will continue to be supported. The only real drawback to Frame mode is the lack of a dedicated VTR to use in an edit suite for capture purposes. Canon offers an HDV camcorder, the HV10, that supports Frame mode playback and can be used as a capture deck, but I doubt we'll ever see a traditional VTR that will be compatible with Frame mode. Fortunately there are a variety of tapeless recording solutions available (such as the FireStore FS-C) which are slowly but surely dispensing with the need for a dedicated capture deck anyway. Hope this helps, |
It appears to me that 24F(P) is here to stay. All the high end cameras do it, XDCAM HD does it, DV does it (XL2, DVX100b). The new Sony V1 does it. And speaking of that camera...I think this is correct--it also uses interlace chips like the HXA1/G1/XLH1, but Sony says P instead of F. Is that right? The method of extracting P from I is different from the way Canon does it, but the chips are also I?
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I own a HVX 200 (24p) and from what i'v seen so far from the H1, the motion looks exactly the same.
I think the difference is only the "container". So to me the H1 has true 24p. |
Thanks Chris,
This clears some things up. By first run I meant including the H1. I also know about the VTR issue & that is one of my concerns. I've been a loyal Canon fan for years, Still cameras & an XL1s, but I just sent a project off to National Geo & they hardly ever take SD anymore - so it's upgrade time & decisions. "Canon is one of the top four camcorder manufacturers in the world, with a significant market share in this industry, so I think it's safe to assume that Frame mode will continue to be supported." My concern was based on if they (Canon) abandon it. The A1 is still on my list, and would have been at the top of it, but I'll be collaborating with someone on my next project & since we're both upgrading (He's Sony & I'm Canon) we've been trying to figure out which way to go. Thanks for the posts, they help a lot. Have a great holiday, Peace, Chris |
I would most definately go with canon. I wouldn't be able to stand the 1/4" chips on the new sonys. I would take an fx1 over the fx7 and same with the z1 and v1. Canon still trumps all.
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One writes discrete frame to tape that no VCR can handle, the other writes frames split into fields that any HDV VCR will handle (even the Canon cameras) but poses some issue with correct handling in almost all NLEs. In the end the decider might be as trivial as you've already got a good supply of batteries and a charger for the Canon or Sony, or which dealer network has the best service. Both those factors steer me to the Sony but boy it's a tough call. |
Very well said, Bob. There really is not a whole lot of difference in sensor size between 1/4" and 1/3" chips. They're both small compared to 1/2" and I think too many people try to make an issue of the sensor size down at this level. Other factors are more important and carry a greater impact than the tiny bit of difference between the 1/4" and 1/3" sizes.
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Yeah it is a tough call, especially, for me that has had nothing but great experiences with Canons. But if their next run of cameras are 24P, that would be a real hassle to have to have 2 VTRs.
Chris I will be using a HD, but a lot of what I shoot especially in the next 2 projects I'll be doing, will be out in the "bush" for extended periods, so I don't want to have to rely on a HD/extra batteries. |
Chris,
I agree that folks make too much out of sensor size, especially between 1/4 and 1/3. The DOF is not all that different (at these ridiculous DOF's anyway) but I am curious to see how the 1/4" affects low-light performance. I know Sony's A1U single CMOS killed low light, so I wonder how three smaller CMOS will hold up to Canon's three bigger CCD's. |
Canon HXA1 is superior in low-light
Sony`s 1/4 sensors produce quite noticeable noise when compared to 1/3 Canon`s in low-light. You can download many test shots from Sony biased Wolfgang`s HDV blog http://www.fxsupport.de/15.html
Cheers, T |
Matthew, the difference in depth of field between 1/4" and 1/3" chips seems to me to be as big as the difference in depth of field between 1/3' and 1/2" and between 1/2" and 2/3". The smaller the chips, the greater the depth of field. With 1/3" chips it is possible to soften the background a bit for head and shoulder interview type shots (which I do a lot), but not with 1/4" chips. You can, of course, do so with a really tight ECU.
The other two factors about smaller chips include needing more light, and needing a wider lens for the same viewing area. These three things make me not want do drop any smaller than 1/3", even though with the newer chips the clarity and sharpness of the image is probably very close to the larger chips. |
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The resolution of the ClearVid 3-Cmos cameras is definately impressive however. |
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Second questions, I thought that 24F on the H1 and A1/G1 where basically progressive frames captured from interlaced sensors at reduced (but nearly undetectable reduction) vertical resolution. While Canon hasn't published their algorithm, how his my understanding incorrect? David |
@ "How does Frame mode differ from the HDV storage on a camera like the V1?"
In short: Frame mode writes one whole progressive frame, the V1 writes the progressive frame (say 25P) in an interlaced stream with two identical fields, like the panasonic dvx. So it repeats the whole frame. (I think I describe it ok -in short- ) @ "Second questions, I thought that 24F on the H1 and A1/G1 where basically progressive frames captured from interlaced sensors at reduced (but nearly undetectable reduction) vertical resolution. While Canon hasn't published their algorithm, how his my understanding incorrect?" The V1 has progressive sensors. The A1/G1 interlaced, it scans the sensor twice at doubled scanrate and creates a frame out of it in the Digital processor. Its V-res is somewhat reduced but remains enormous. The timing is similar as 24P 25P. |
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Bill is right -- it is not "similar." Rather it is "identical."
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My English.. I did a good job here.
It's for editing software like FCP identical like the same, if you look at the motion, it is as 24P 25P from an other system. |
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In progressive video (25p or 30p) a progressive frame is imaged all at once, and then split into fields for recording. The fields were created at the same instant in time, but contain different data -- each field contains half the progressive picture. In interlaced video the fields are created in different instants in time. In progressive video (when recorded to an interlaced stream) the fields are created at the same instant in time. |
Originally Posted by Raymond Toussaint
In short: Frame mode writes one whole progressive frame, the V1 writes the progressive frame (say 25P) in an interlaced stream with two identical fields, like the panasonic dvx. Maybe short is too short. with two -in time- identical fields, If they were identical in data the resolution would be doubled, not cut in half I think. So the even/oneven lines vertical sync method remains, but is now filldup with in time unchanged data. |
Both A1 frame mode and V1 progressive mode are written to an interlaced 1080i HDV file. In both cases the entire 1440x1080 image is a single instant.
How does the recording differ? |
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The V1 embeds its progressive frames into a 60i interlaced data stream, so it employs 2:3 pulldown to spread 24 frames across 60 fields. The A1 doesn't do anything like that. It writes 24 progressive frames to the tape, progressively. Which is why A1 24F/30F footage won't play back on Sony equipment -- it's a totally different format. |
If 1080i HDV supports progressive frames directly, why would they need a 3:2 pulldown? It makes sense in DV, which doesn't support 24 frames/sec or progressive frames. But if HDV supports both, why use interlaced frames with a 3:2 pulldown?
Thanks, David |
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Canon A1 uses an interlaced sensor-->(reads it twice) --> to write it as one progressive frame Sony V1 uses a progressive sensor--> (reads it once) --> to write it in two interlaced fields But Barry: If the two -in time- identical fields, were identical in data the resolution would be doubled, not cut in half. There is more data. |
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Richard |
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In the attached images, dvx100be @ 1/250s, there are no interlace artefacts, of course. These 2 images are 1/24s apart, but each is @ 1/250s so motion is relatively frozen. This is essential to me, for crisp slow motion playback of fast moving action. Does 24F enable this, or is it only similar to 24P at much slower shutter speeds? Thanks Christophe |
Yes, see this post:
http://www.dvinfo.net/conf/showpost....1&postcount=53 |
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Then in the 1080 realm you have the original 1080 spec, which is what Sony is compliant with, which is 1080/60i and 1080/50i and that's it. Then Canon came along and invented their own recording format for 30F, 25F and 24F. So now the HDV specification has been extended to include those modes, but Sony doesn't support any of them. You can't play 24F, 25F, or 30F footage on any Sony equipment. Yet it's all "HDV". Very confusing. So, therein lies the crux of the matter. Sony gear doesn't support progressive recording, so when they made a progressive camcorder they chose to implement the progressive footage within an interlaced data transport stream. That gave them backwards compatibility with all their other HDV equipment; any Sony (or Canon) camera or deck can read any Sony HDV footage. JVC cameras and decks can't, but Sony cameras & decks, and Canon cameras, can. Had they used progressive recording, they'd be in the same boat Canon is in, which is that no HDV deck can read Canon 24F, 25F, or 30F footage. But, Canon records progressively rather than embedded in an interlaced data stream, which should yield technically superior results. But at the expense of having made their own proprietary format which no deck can read (because Canon doesn't make decks). To further confuse the issue, when the Canon outputs 24F over HD-SDI or analog component, it does add 2:3 pulldown into the signal. It's only the HDV tape itself where the footage is encoded as raw 24-frame progressive; on the analog or HD-SDI outputs it's treated as a 60i data stream. |
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Now I understand, I see the picture. I was on 99.5 % now I am on 99.8 %. @ Barry Green "Had they used progressive recording, they'd be in the same boat Canon is in, which is that no HDV deck can read Canon 24F, 25F, or 30F footage. But, Canon records progressively rather than embedded in an interlaced data stream, which should yield technically superior results. But at the expense of having made their own proprietary format which no deck can read (because Canon doesn't make decks)." There is a growing behaviour to shoot (next to tape) on memory cards, harddisk, with laptop computers or portable drives. Doing so and in the future, gives Canon a system that is free from videodecks, 24F, 25F, 30F is technically a better format and shooting tapeless and editing on any system is possible. Even Panasonic HVX200 users are in big numbers working with Firestore disks, and they can choose to go P2. |
I think the reason HVX200 users are recording to Firestore is because of the tremendous cost and low capacity of P2 cards.
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Yes,... but that is not the issue here. What do you want to say in relation to 24, 25, 30F? I don't get it. I am talking about the Canon HDV implementation and how to work with it without a tapedeck. |
Without a deck you use the camera as a deck, or you buy the HV10 for about 1200 bucks to use as a deck. It will play all the different modes, so no problem there. For me, using the camera as a deck is working OK for personal stuff. But for the company, we couldn't live without regular decks.
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I actually prefer the way Canon does it. Yes it may not work in any decks but how many of us really go out and buy a deck after we bought a new camera?
1. progressive encoding is just cleaner per bitrate compared to interlaced at the same bitrate. 2. progressive encoding uses a cleaner form of 4:2:0 color that gives much better results and is closer to how jpeg chroma compression works on still images. 3. Most NLE's now support 24F editing while the SONY flavor may take a few months to get supported and who knows how many bugs there will be at first. 4. 24F has more bits and less artifacts per frame due to less number of frames compared to 30F or 60i. SONY 24P will have the same quality level as 60i shot with the same camera. There are some things I really like about the SONY cameras but the best image in the world doesn't mean much if it is encoded badly. Look at PBS HD. They use much higher end HD cameras then we are using but yet the channel suffers in quality due to bad compression. A lot of people notice 720p channels to be cleaner then 1080i channels while having almost the same level of detail. The 720p channels do not use better cameras but 720p is easier to encode. Not because it has less pixels which isn't really true when you talk about 60p but mainly because it is progressive in nature. |
Dude, I was wondering why PBS looks so bad! Especially compared to discovery!
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Codecs and compression techniques are everything when it comes to digital delivery!
Just look @ Blu-Ray, their first generation of Blu-Ray discs we're GARBAGE (despite their brilliant 1080p advertising ploy). The quality of House of flying daggers was a joke (the SD dvd looked bette) which imo is unacceptable for a $1000 'top of the line state of the art' video player. Sony blames the first generation Blu-Ray discs to look like junk cuz they were encoded via Mpeg2 & not VC-1 but that is just BS since Sony uses Mpeg2 for HDV, they well know that Mpeg2 can be effectly used to encode HD material VERY VERY well. |
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As for PBS I think they broadcast at around only 12 mbits/s which is why it looks so bad. at that rate I think they would have been better off broadcasting as 720p or even 854x480x60p. Anyways getting back on topic here, the 24F method is about the cleanest form of mpeg2 encoding you can find in any of these cameras and can even come close in terms of raw encoding quality to the 35 mbits mode in XDCAM HD. The JVC method of HDV is also very clean and I'm sure it is even better with the new super encoder in the 200 series of the cameras. |
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Since all the tape drive are 25Mb/sec, the JVC is encoding 24 1280x720 frames, the Canon 24 1440x1080 frames, and the Sony 60 1440x540 frames, does that mean that the JVC has less compression than the Canon which in turn has less than the Sony? Or can the Sony set a flag to that leaves the duplicate frame blank in the stream? Does this impact image quality in the actual implementations? The HD-SDI output of the H1 and G1, and HDMI output of the V1 would bypass both these issues. Has anyone posted HD-SDI and HDMI outputs respectively? Thanks, David |
We have had significant incompatibilites between brands in the SD realm as well. Almost nothing made on a Canon recorder wants to play back cleanly and consistently on a Sony or JVC playback deck. Yet it will always play back wonderfully in the cam that it was made in.
Our solution was to dub down from the cam that the master is shot in, to our playback deck of choice. Can you process HDV masters in a similar way? Could you do the same thing with HDV, dubbing for example, a Canon A1-made master to a Sony HVR-M15U or other playback deck, and thereby achieve reliable playback of your Canon made tapes? There should not be any appreciable signal loss in the process. |
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For SDI output examples, look through the Clips subfourm in the XL H1 area. There are a quite a few links there. A lot of it is down-sampled at capture to DVCProHD (1280x1080 anamorphic), though. Not sure off the top of my head if there are any Cineform Prospect 1920x1080 clips in the subforum. |
Yes that's right, HDV1 (1280x720 from JVC) is 19Mb/s.
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