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Guest
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 Posted:
Thu Sep 29, 2005 2:26 am Post subject:
680k Pixel MiniDV w/340K Effective Pixels for a MiniDV Camco |
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I'm considering getting a JVC GRD250 MiniDv Digital Camcorder. (it's
only $200 brand new)
I have a Zenith DVD Recorder (DVR 413) that has a firewire input which
should work well for capturing the MiniDV's video.
After a quick search to see what I could find out about the JVC, I
discovered that it has a '680K pixel CCD w/340K effective pixels for
video'.
My question is; does the '340K effective pixel' represent the normal
video quality (and/or resolution) for a low-end MiniDV?
Is MiniDV video like Hi-8 camcorders in that the video to tape
resolution is less than what the camcorder will actually take?
If anyone is familiar with this model, please let me know what you think
of it.
Thanks for any help.
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PTravel
Guest
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| Posted:
Thu Sep 29, 2005 3:44 am Post subject:
Re: 680k Pixel MiniDV w/340K Effective Pixels for a MiniDV C |
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<allr1@webtv.net> wrote in message
news:29188-433B0A7C-77@storefull-3158.bay.webtv.net...
| Quote: |
I'm considering getting a JVC GRD250 MiniDv Digital Camcorder. (it's
only $200 brand new)
I have a Zenith DVD Recorder (DVR 413) that has a firewire input which
should work well for capturing the MiniDV's video.
After a quick search to see what I could find out about the JVC, I
discovered that it has a '680K pixel CCD w/340K effective pixels for
video'.
My question is; does the '340K effective pixel' represent the normal
video quality (and/or resolution) for a low-end MiniDV?
Is MiniDV video like Hi-8 camcorders in that the video to tape
resolution is less than what the camcorder will actually take?
|
miniDV resolution is 720 x 480 pixels (NTSC) for a total of 345,600 pixels,
i.e. approx. 340k.
Camcorders that have higher density sensors usually use them for still
imaging. Some (but, generally, not bottom-of-the-line machines) can do
pixel subsampling, i.e. using the additional pixels to "average," producing
a slightly better image.
Resolution is a different issue that is not necessarily related to the
number of pixels on the sensor. Hi8 was capable of around 400-450 lines per
inch. MiniDV, in theory, is capable of up to 525 lines per inch. In
practice, however, you will not reach those kinds of resolutions which cheap
consumer equipment. Maximum resolution is a function of optics and
electronics, as well as sensors. A 340k sensor machine, theoretically,
could reach 525 lines, but a cheapie consumer model almost certainly
won't -- I've heard of some consumer camcorders that resolve as little as
275 lines, which puts them in VHS territory.
| Quote: |
If anyone is familiar with this model, please let me know what you think
of it.
Thanks for any help.
|
|
|
| Back to top |
|
|
Guest
|
| Posted:
Fri Sep 30, 2005 2:13 am Post subject:
Re: 680k Pixel MiniDV w/340K Effective Pixels for a MiniDV C |
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PTravel wrote:
" miniDV resolution is 720 x 480 pixels (NTSC) for a total of 345,600
pixels, i.e. approx. 340k.
^^================================^^
The info I found on the JVC camcorder said that the video resolution is
640 x 480. That
may be the resolution of what the tape can record and not the camcorder
itself.
I have a Hi-8 camcorder now, but if I use it for shooting video of
anything that's farther than
50' away (w/o zoom) the subject is very grainy and hard to see. (what's
recorded on tape)
I'm hoping that miniDV's better resolution will be able to handle
objects that are farther away.
PTravel wrote:
" Camcorders that have higher density sensors usually use them for still
imaging. Some (but, generally, not bottom-of-the-line machines) can do
pixel subsampling, i.e. using the additional pixels to "average,"
producing a slightly better image. "
^^================================^^
Yes, the info on the JVC said Image resolution (still, as opposed to
video) is 1024 x 768.
It also mentions that the JVC uses a 'super high-band processor that
restores the high-band components of the luminance signal to ensure a
crisp picture with 520 lines of resolution' for video.
PTravel wrote:
" Resolution is a different issue that is not necessarily related to the
number of pixels on the sensor. Hi8 was capable of around 400-450 lines
per inch. MiniDV, in theory, is capable of up to 525 lines per inch. In
practice, however, you will not reach those kinds of resolutions which
cheap consumer equipment. Maximum resolution is a function of optics and
electronics, as well as sensors. A 340k sensor machine, theoretically,
could reach 525 lines, but a cheapie consumer model almost certainly
won't -- I've heard of some consumer camcorders that resolve as little
as 275 lines, which puts them in VHS territory. "
^^===============================^^
Well it looks like 340K effective for video is normal for a low-end
miniDV camcorder.
2 more question come to mind:
1) What video resolution is considered 'broadcast quality'?
2) Does miniDV and Hi-8 tape record video at less resolution than the
camcorder is capable of? (I've recorded the Hi-8 camcorder's signal
directly into a DVD recorder and it seems to yield a better picture than
what plays back on the Hi-8 tape) |
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PTravel
Guest
|
| Posted:
Fri Sep 30, 2005 3:21 am Post subject:
Re: 680k Pixel MiniDV w/340K Effective Pixels for a MiniDVCa |
|
|
<allr1@webtv.net> wrote in message
news:24682-433C590F-31@storefull-3153.bay.webtv.net...
| Quote: | PTravel wrote:
" miniDV resolution is 720 x 480 pixels (NTSC) for a total of 345,600
pixels, i.e. approx. 340k.
^^================================^^
The info I found on the JVC camcorder said that the video resolution is
640 x 480. That
may be the resolution of what the tape can record and not the camcorder
itself.
|
It's not. I'm not familiar with the JVC camcorder. However, miniDV is a
standard that uses 720 x 480 pixels for NTSC video (which is the standard
used in the US). If the camcorder can't generate a digital video stream
that is 720 x 480, it doesn't conform to the standard. This means that (1)
it will have reduced resolution, and (2) you may have trouble editing it.
640 x 480 is the VGA standard, and a lot of media software and hardware can
handle it.
Video resolution encompasses two separate aspects -- the number of pixels
per frame, e.g. 720 x 480 or 640 x 480, and the extent to which fine detail
can be resolved, measured in horizontal and vertical lines per inch. The
two are related, but the fact that a camcorder has 720 x 480 pixels does not
necessarily mean that it can resolve fine detail well. The number of
horizontal by vertical pixels only describes the digital format of a frame.
The lines-per-inch resolution measures the actual resolving power of the
system, and is a product of the quality of the lens, the accuracy of focus,
the dynamic range of the sensor, and the ability of the electronics to
exclude noise.
As I mentioned in my earlier post, the miniDV allows for a theoretical
maximum horizontal resolution of 525 lines per inch. However, most low-end
consumer miniDV camcorders will not approach this. A 640 x 480 camcorder
sounds like a real cheapie -- I wouldn't expect much from it.
| Quote: |
I have a Hi-8 camcorder now, but if I use it for shooting video of
anything that's farther than
50' away (w/o zoom) the subject is very grainy and hard to see. (what's
recorded on tape)
|
What you've described relates to the horizontal and vertical resolution,
i.e. how many lines per inch your camcorder can resolve. There are many,
many factors that effect resolution.
| Quote: | I'm hoping that miniDV's better resolution will be able to handle
objects that are farther away.
|
As I said, the theoretical maximum resolution of miniDV exceeds that of the
theoretical maximum of Hi8 -- 525 lines per inch versus 450 lines per inch,
respectively. However, these are only theoretical maximums.
I have an old Sony TR-600 Hi8 camcorder. This was a
close-to-the-top-of-the-line consumer camera Sony manufactured 10 or 11
years ago. It has better resolution than many low-end consumer miniDV
camcorders that are on the market today. However, I also have a Sony VX2000
miniDV camcorder. This is a prosumer model that produces high quality
video. Sony claims that maximum resolution, i.e. 525 lines, for this
camera, and I have no reason to disbelieve that.
To answer your question, a cheap consumer miniDV camcorder will not
necessarily have better resolution than your Hi8 camcorder, and may have
dramatically poorer resolution. It will also, undoubtedly, have far poorer
low light performance (though that's another discussion entirely). As I
said, there are miniDV camcorders on the market that barely achieve VHS
resolution (250 lines per inch or so). Merely switching formats does not
ensure that you'll get better resolution.
| Quote: |
PTravel wrote:
" Camcorders that have higher density sensors usually use them for still
imaging. Some (but, generally, not bottom-of-the-line machines) can do
pixel subsampling, i.e. using the additional pixels to "average,"
producing a slightly better image. "
^^================================^^
Yes, the info on the JVC said Image resolution (still, as opposed to
video) is 1024 x 768.
|
Still resolution is meaningless to video resolution, except that higher
density sensors tend to have poorer low-light capability and introduce more
artifacts to the video.
| Quote: |
It also mentions that the JVC uses a 'super high-band processor that
restores the high-band components of the luminance signal to ensure a
crisp picture with 520 lines of resolution' for video.
|
520 lines would be great. I don't believe it, though, if the video
resolution is 640 x 480.
| Quote: |
PTravel wrote:
" Resolution is a different issue that is not necessarily related to the
number of pixels on the sensor. Hi8 was capable of around 400-450 lines
per inch. MiniDV, in theory, is capable of up to 525 lines per inch. In
practice, however, you will not reach those kinds of resolutions which
cheap consumer equipment. Maximum resolution is a function of optics and
electronics, as well as sensors. A 340k sensor machine, theoretically,
could reach 525 lines, but a cheapie consumer model almost certainly
won't -- I've heard of some consumer camcorders that resolve as little
as 275 lines, which puts them in VHS territory. "
^^===============================^^
Well it looks like 340K effective for video is normal for a low-end
miniDV camcorder.
|
340K isn't "normal" -- it's what's required to produce a 720 x 480 image.
My VX2000 has ccds with 380k pixel sensors, though it has 3 separate CCDs,
one for each primary color.
| Quote: |
2 more question come to mind:
1) What video resolution is considered 'broadcast quality'?
|
I'm not sure if there's an actual standard, though there may be.
Broadcast-quality monitors usually resolve 600-700 lines.
| Quote: |
2) Does miniDV and Hi-8 tape record video at less resolution than the
camcorder is capable of? (I've recorded the Hi-8 camcorder's signal
directly into a DVD recorder and it seems to yield a better picture than
what plays back on the Hi-8 tape)
|
I'm not quite sure what you're asking. As I said, resolution is the result
of the particular combination of lens and electronics, as well as the
particular standard employed. The Hi8 format can accomodate up to 450 lines
per inch, but very few camcorders are going to reach that. However, some do.
The miniDV format can accomodate up to 525 lines per inch, but very few
camcorders are going to reach that. However, some do.
As for getting better results taking the analog video signal from a Hi8 and
recording it to a DVD recorder, there are so many variables that it's
impossible to say what's happening. Analog signals must be digitized to
make a DVD. The digitization process is done by the DVD recorder in
realtime. The resulting digitized video is then compressed to DVD-compliant
mpeg2 and written to the DVD. Mpeg2 compression is a black art that is
dependent on the particular software employed. Frequently, consumer-grade
DVD-compliant mpeg2 video transcodes look soft -- this is done to repress
digital artifact that result from the conversion of analog to digital. Many
people prefer a softer picture to a picture filled with jaggies and other
digital artifacts. This may result in a subjective judgement that the
picture is "better," but it really isn't.
MiniDV camcorders perform the digital conversion internally. They output a
digital video stream (and some of them can also output analog video as
well). Again, the quality of the video is going to be dependent on all the
components that make up the camera -- lens, sensors, electronics, etc.
> |
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Gene E. Bloch
Guest
|
| Posted:
Tue Oct 04, 2005 2:44 am Post subject:
Re: 680k Pixel MiniDV w/340K Effective Pixels for a MiniDVCa |
|
|
"PTravel" <ptravel88-usenet@yahoo.com> wrote in
news:3q37n0Fd30seU1@individual.net:
| Quote: |
allr1@webtv.net> wrote in message
news:24682-433C590F-31@storefull-3153.bay.webtv.net...
PTravel wrote:
" miniDV resolution is 720 x 480 pixels (NTSC) for a total of
345,600 pixels, i.e. approx. 340k.
^^================================^^
The info I found on the JVC camcorder said that the video
resolution is 640 x 480. That
may be the resolution of what the tape can record and not the
camcorder itself.
It's not. I'm not familiar with the JVC camcorder. However,
miniDV is a standard that uses 720 x 480 pixels for NTSC video
(which is the standard used in the US). If the camcorder can't
generate a digital video stream that is 720 x 480, it doesn't
conform to the standard. This means that (1) it will have reduced
resolution, and (2) you may have trouble editing it. 640 x 480 is
the VGA standard, and a lot of media software and hardware can
handle it.
Video resolution encompasses two separate aspects -- the number of
pixels per frame, e.g. 720 x 480 or 640 x 480, and the extent to
which fine detail can be resolved, measured in horizontal and
vertical lines per inch. The two are related, but the fact that a
camcorder has 720 x 480 pixels does not necessarily mean that it
can resolve fine detail well. The number of horizontal by
vertical pixels only describes the digital format of a frame. The
lines-per-inch resolution measures the actual resolving power of
the system, and is a product of the quality of the lens, the
accuracy of focus, the dynamic range of the sensor, and the
ability of the electronics to exclude noise.
As I mentioned in my earlier post, the miniDV allows for a
theoretical maximum horizontal resolution of 525 lines per inch.
However, most low-end consumer miniDV camcorders will not approach
this. A 640 x 480 camcorder sounds like a real cheapie -- I
wouldn't expect much from it.
I have a Hi-8 camcorder now, but if I use it for shooting video
of anything that's farther than
50' away (w/o zoom) the subject is very grainy and hard to see.
(what's recorded on tape)
What you've described relates to the horizontal and vertical
resolution, i.e. how many lines per inch your camcorder can
resolve. There are many, many factors that effect resolution.
I'm hoping that miniDV's better resolution will be able to handle
objects that are farther away.
As I said, the theoretical maximum resolution of miniDV exceeds
that of the theoretical maximum of Hi8 -- 525 lines per inch
versus 450 lines per inch, respectively. However, these are only
theoretical maximums.
I have an old Sony TR-600 Hi8 camcorder. This was a
close-to-the-top-of-the-line consumer camera Sony manufactured 10
or 11 years ago. It has better resolution than many low-end
consumer miniDV camcorders that are on the market today. However,
I also have a Sony VX2000 miniDV camcorder. This is a prosumer
model that produces high quality video. Sony claims that maximum
resolution, i.e. 525 lines, for this camera, and I have no reason
to disbelieve that.
To answer your question, a cheap consumer miniDV camcorder will
not necessarily have better resolution than your Hi8 camcorder,
and may have dramatically poorer resolution. It will also,
undoubtedly, have far poorer low light performance (though that's
another discussion entirely). As I said, there are miniDV
camcorders on the market that barely achieve VHS resolution (250
lines per inch or so). Merely switching formats does not ensure
that you'll get better resolution.
PTravel wrote:
" Camcorders that have higher density sensors usually use them
for still imaging. Some (but, generally, not bottom-of-the-line
machines) can do pixel subsampling, i.e. using the additional
pixels to "average," producing a slightly better image. "
^^================================^^
Yes, the info on the JVC said Image resolution (still, as opposed
to video) is 1024 x 768.
Still resolution is meaningless to video resolution, except that
higher density sensors tend to have poorer low-light capability
and introduce more artifacts to the video.
It also mentions that the JVC uses a 'super high-band processor
that restores the high-band components of the luminance signal to
ensure a crisp picture with 520 lines of resolution' for video.
520 lines would be great. I don't believe it, though, if the
video resolution is 640 x 480.
PTravel wrote:
" Resolution is a different issue that is not necessarily related
to the number of pixels on the sensor. Hi8 was capable of around
400-450 lines per inch. MiniDV, in theory, is capable of up to
525 lines per inch. In practice, however, you will not reach
those kinds of resolutions which cheap consumer equipment.
Maximum resolution is a function of optics and electronics, as
well as sensors. A 340k sensor machine, theoretically, could
reach 525 lines, but a cheapie consumer model almost certainly
won't -- I've heard of some consumer camcorders that resolve as
little as 275 lines, which puts them in VHS territory. "
^^===============================^^
Well it looks like 340K effective for video is normal for a
low-end miniDV camcorder.
340K isn't "normal" -- it's what's required to produce a 720 x 480
image. My VX2000 has ccds with 380k pixel sensors, though it has 3
separate CCDs, one for each primary color.
2 more question come to mind:
1) What video resolution is considered 'broadcast quality'?
I'm not sure if there's an actual standard, though there may be.
Broadcast-quality monitors usually resolve 600-700 lines.
2) Does miniDV and Hi-8 tape record video at less resolution than
the camcorder is capable of? (I've recorded the Hi-8 camcorder's
signal directly into a DVD recorder and it seems to yield a
better picture than what plays back on the Hi-8 tape)
I'm not quite sure what you're asking. As I said, resolution is
the result of the particular combination of lens and electronics,
as well as the particular standard employed. The Hi8 format can
accomodate up to 450 lines per inch, but very few camcorders are
going to reach that. However, some do. The miniDV format can
accomodate up to 525 lines per inch, but very few camcorders are
going to reach that. However, some do.
As for getting better results taking the analog video signal from
a Hi8 and recording it to a DVD recorder, there are so many
variables that it's impossible to say what's happening. Analog
signals must be digitized to make a DVD. The digitization
process is done by the DVD recorder in realtime. The resulting
digitized video is then compressed to DVD-compliant mpeg2 and
written to the DVD. Mpeg2 compression is a black art that is
dependent on the particular software employed. Frequently,
consumer-grade DVD-compliant mpeg2 video transcodes look soft --
this is done to repress digital artifact that result from the
conversion of analog to digital. Many people prefer a softer
picture to a picture filled with jaggies and other digital
artifacts. This may result in a subjective judgement that the
picture is "better," but it really isn't.
MiniDV camcorders perform the digital conversion internally. They
output a digital video stream (and some of them can also output
analog video as well). Again, the quality of the video is going
to be dependent on all the components that make up the camera --
lens, sensors, electronics, etc.
|
One correction is necesary here. The resolution is in lines, not
lines per inch. That is, lines per picture. (More or less; there is
a convention, which I forget, in expressing the horizontal
resolution.)
Consider that you might be showing the tape on a 12" TV and I might
be using a 24" TV - or vice versa... Surely you don't believe that
the picture on the smaller TV shows around 5000 lines in its roughly
10" height, while the other shows around 10000 lines.
Regardless of the resolution of the picture, miniDV tape has a fixed
format with 720x480 pixels (NTSC), so a source containg a different
number of pixels is interpolated or extrapolated to fit.
HTH,
Gino
--
Gene E. Bloch (Gino)
letters617blochg3251
replace the numbers by "at" and "dotcom" |
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PTravel
Guest
|
| Posted:
Tue Oct 04, 2005 3:31 am Post subject:
Re: 680k Pixel MiniDV w/340K Effective Pixels for a MiniDVCa |
|
|
"Gene E. Bloch" <hamburger@NOT_SPAM.invalid> wrote in message news
| Quote: | One correction is necesary here. The resolution is in lines, not
lines per inch. That is, lines per picture. (More or less; there is
a convention, which I forget, in expressing the horizontal
resolution.)
|
Right. I don't know what I was thinking of. Thanks for the correction.
| Quote: |
Consider that you might be showing the tape on a 12" TV and I might
be using a 24" TV - or vice versa... Surely you don't believe that
the picture on the smaller TV shows around 5000 lines in its roughly
10" height, while the other shows around 10000 lines.
Regardless of the resolution of the picture, miniDV tape has a fixed
format with 720x480 pixels (NTSC), so a source containg a different
number of pixels is interpolated or extrapolated to fit.
HTH,
Gino
--
Gene E. Bloch (Gino)
letters617blochg3251
replace the numbers by "at" and "dotcom" |
|
|
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|
|
Gene E. Bloch
Guest
|
| Posted:
Tue Oct 04, 2005 11:33 pm Post subject:
Re: 680k Pixel MiniDV w/340K Effective Pixels for a MiniDVCa |
|
|
"PTravel" <ptravel88-usenet@yahoo.com> wrote in
news:3qdppvFd9n5jU1@individual.net:
| Quote: |
"Gene E. Bloch" <hamburger@NOT_SPAM.invalid> wrote in message news
One correction is necesary here. The resolution is in lines, not
lines per inch. That is, lines per picture. (More or less; there
is a convention, which I forget, in expressing the horizontal
resolution.)
Right. I don't know what I was thinking of. Thanks for the
correction.
|
Probably just habit :-)
I'm always glad to nitpick...
Gino
--
Gene E. Bloch (Gino)
letters617blochg3251
replace the numbers by "at" and "dotcom" |
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