Ideal DV camera for telecine (Video Cinemate)

[mattias]

None the less, it is sometimes just as amazing to observe you seemingly point to the ground while commenting on the clouds.

probably true. i'm just the kind of guy (anal as hell) who wants everything in a discussion to be formally correct, even if it complicates things way too much. sorry about that i guess. :-)

Again, what formats and why would they be relevant to this discussion if not miniDV?

here's the quote that started it: "Cameras like the Sony TR900 will offer a resolution of approx 600 lines if the video signal is tapped directly from the cam via the analog Y/C output. I think I have seen other cameras yield 700 lines with the same setup." crimson said this couldn't be true because no cameras can output more than 480 lines. i explained that the numbers were referring to horizontal resolution, and he said that if that was case the limit was 720. this is of course not true. whether there are tape formats that can record more (there are) isn't even relevant.

/matt

[Guest]

DV is fixed at 720x480. No matter what camera you use your final output is only 720x480. You are argue that some cameras can do more. Which I replied yes they SEE but that is pointless since it must go through compression and format regulation that you are still only getting 720x480.

"a video signal can offer a resolution of 19436x486 or 34x525, or 720x480. "


What is the focus on the written on tape - because a video signal must either be on tape, displayed on monitor or broadcasted - either way it must go through some video format regualtion (NTSC, PAL, DV, Beta, etc) - which means back to 720 x 480.


""and there *are* indeed cameras as well as tape formats that can resolve more than 720 lines."

Name one (SD not HD). Written on tape."

"and what's with this focus on tapes all of a sudden? this discussion started with tapes explicitly excluded if i remember correctly"


Look at what you said - "tape formats"

How about those cameras can SEE 800 lines (like a Beta for example) - so what? Because of format regualtions even the component RGB out of a Beta is limited by bandwidth - thus back to 720.


"i'm just the kind of guy (anal as hell) who wants everything in a discussion to be formally correct, even if it complicates things way too much. sorry about that i guess. "


Dont be - I actually enjoy it and it breathes life sometimes...

[wahiba]

My TV has 625 line - and not all of them are used for the picture -say 600, so why is it necessary to have more than 600 lines for domestic television?

Surely 600 odd good lines up front are better than 700 that have to be mucked about with?

And now something for the weekend

As my current set up will only mange 384 x 288 effectively, and this is the quality of VHS, need I worry?

Mind you, surely a digital recording to be played back on a digital system is only limited by the number of phosphors, or equivalent physical elements on the screen?

Discuss - and i will collect them in on Monday for marking!

[S8 Booster]

Check: UNDERSTANDING TV CAMERA RESOLUTION

http://videoexpert.home.att.net/artic1/201res.htm

[S8 Booster]

-> Or simply: why not stick to FILM->FILM?

1:1 "lossfree" projection,

and 1000% more excitement!

[wahiba]

Thanks for the link. It is quite interesting and does answer the question.

[S8 Booster]

DV vs. Betacam SP: 4:1:1 vs. 4:2:2, Artifacts and Other Controversies

http://www.chumpchange.com/parkplace/vi ... v-beta.htm

(Check the roiginal site for more and better details)

Horizontal Resolution and Bandwidth of Analog Recording Formats

Traditionally, resolution of analog video cameras, recording formats, and monitors has been expressed as "TV lines" or "horizontal lines." Originally, TV lines were determined by the ability to clearly distinguish sets of vertical lines in a standard TV test pattern. Subsequently, horizontal resolution became related to the bandwidth of the recording format. The generally-accepted "rule of thumb" is 80 lines per MHz of luminance bandwidth for recording formats. The following table lists the lines of horizontal resolution of various recording formats, based on Sony and other manufacturers' data sheets, with the NTSC broadcast signal added for comparison. Bandwidth is implied from the "rule of thumb."

Format /Horizontal Lines// Implied Bandwidth, MHz/
VHS and 8-mm VCRs /240// 3.0/
U-matic (3/4-inch) VCRs /250// 3.1/
U-matic SP VCRs /330// 4.1/
NTSC Broadcast Signal /330// 4.1/
S-VHS and Hi8 VCRs /400// 5.0/
Laserdisc /425// 5.3/
DVD Video /500// 6.3/
DV Formats /500// 6.3/

Note: DV formats include consumer DV, DVCPRO (25 Mbps), and DVCAM, all of which use the same video data format for NTSC. Horizontal resolution of professional-grade three-CCD video cameras (often 750 or more) are related to the number of pixels per CCD, the type of CCD (field interline transfer, HyperHAD, etc.), the spatial relationship between the three CCDs, and internal signal processing techniques. Increasing the resolution of the camera section results in improved perceived image quality, regardless of the resolution of the recording format used. Horizontal resolution of monitors is determined by a combination of the aperture mask dot (or grill) pitch and design, as well as the video signal bandwidth. Sony claims its popular PVM-1354Q (0.25-mm pitch) and PVM-1954Q (0.40-mm pitch) monitors deliver 600-line resolution, corresponding to a theoretical luma bandwidth of 7.5 MHz. Another rule of thumb is that your monitor's resolution (or bandwidth) should exceed that of the recording format, preferably by 25 percent or more.

[S8 Booster]

Another offensive link: Very detailed. Check the tables down the page!

http://sevitech.com/dtv6.htm

While the "back-end" of every consumer DV camcorder will record the same high quality 4:1:1 signal as a professional DV dockable back, the "front-end" might be disappointing. Most of the consumer DV camcorders use only one CCD for imaging. But some use three CCDs just as professional cameras do. But these CCDs are smaller and with less pixels than professional camera CCDs. While broadcasters and videographers debate the usefulness of consumer DV, others are using it successfully. In some circumstances the weaker "front-end" holds up incredibly well, in others it does not. The one aspect that most professionals agree on is that for the best imaging, careful attention must be paid to lighting for the consumer CCDs to produce their best images.

[mattias]

My TV has 625 line - and not all of them are used for the picture -say 600, so why is it necessary to have more than 600 lines for domestic television?

duh, thank you for following the thread so carefully, especially the part about horizontal vs vertical lines.

vertical resolution is fixed and determined by the standard (sorry for using the confusing word "format" before), horizontal is not.

and don't "say" 600. say 576. ;-)

/matt

[wahiba]

Interesting - so if 625 becomes 576 I wonder what 405 (UK) or 819 (F) became?

Ok I know - dead!

[Guest]

here's the quote that started it: "Cameras like the Sony TR900 will offer a resolution of approx 600 lines if the video signal is tapped directly from the cam via the analog Y/C output. I think I have seen other cameras yield 700 lines with the same setup."

Ah, therein lies the further rub of DV. On many (perhaps most? perhaps all?) DV cameras, the Y/C output comes AFTER the DV compression stage!

This was a heated topic of discussion back when the VX-1000 first came out, many people were arguing that using the s-video output straight off the camera head would provide for much better compositing/bluescreen because the signal wouldn't have been decimated by 4:1:1 compression yet. As basis for the argument, they offered that the VX-3 (the Hi8 camera the VX-1000 was based on) provided a much better S-video signal off the head before recorded to tape, where the signal was compromised by the tape format.

Real-world tests proved that there was no improvement in using the signal straight off the camera head, in fact performance was slightly reduced. So we had a camera engineer trace the schematics of the camera, and found that the DV compression stage comes before the analog output stage. As in, there was no such thing as tapping the signal off the camera head, it could only ever put out a post-DV-compression signal.

And that raises the question as to whether ANY DV camera can provide a pure signal, or if it is always post-compression. The argument can be raised that they must always be post-compression since the analog output has to be able to play the signal off the tape. I haven't kept up with the discussion since that original determination about the VX-1000. I guess all I'm saying is that you should never take for granted that the live signal from the camera will be superior to the signal from the tape, because (now that cameras have built-in compression chips) that may not be the case.

[S8 Booster]

Well, my statement was based on a concrete test done but I haven´t time to re.find it.

In the meantime this one might be good to chew on:
Dv / DVCR record mode:



More:
http://www.oakmusic.com/parkplace/video ... _formt.htm

And I really do not care anyway.
I project MOVIES but I have the gear to MAC digitize them up to 1024x768pixels (or any tweaked WS format worked out from it) , if I want to.





[/quote]

[crimson]

"I'm saying is that you should never take for granted that the live signal from the camera will be superior to the signal from the tape, because (now that cameras have built-in compression chips) that may not be the case."

Yes - that is what I said - there are too many variables between the CCD and you computer's hard disk to guarantee that direct PC compression will be better than the built in tape format.

However, there are high end broadcast cameras that are not tape based and have "uncompressed" video output.

[S8 Booster]

Confusion Complete?

http://members.aol.com/_ht_a/ajaynejr/vidres.htm