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· Videophile
#video cameras
13 messages in this thread
Didn't I see something in a recent mag (AC?) that described an adapter for
DigiView that would let you use video sources, etc, with DigiView? Not
real time, but without camera. Similar to what you were describing
before… — Another question: what are results from using a frame grabber
with a camera? ie: instead of using DigiView, use the camera to get the
image (even if it is a photograph, etc). It seems to me that this would be
more flexible way to go, as you could digitize images (using the camera as
a source), or use video in real time. I guess what I am asking is: is there
a decrease in resolution, etc. to go this way? Is DigiView higher
resolution than a frame grabber, etc????? –jp–
That gizmo you saw was the same thing, I think. It can disassemble any NTSC
source (camera or tape playback) but you still have to make 3 passes, as
the output of this gadget has R,G,B as separate signals. These RGB signals
"look" like a single camera output with the filter wheel in front of it. As
far as "bypassing" Digi-View, I don't quite follow. You still need to do
an annalog-to-digital conversion somewhere along the line. If you had a
standalone framegrabber, you're still left with the task of getting the
"grabbed" frame into digital format. The "other" digitizer, Amiga Live!,
does both of these functions. Personally, I think Digi-View has better
results than Live!, in terms of rez & general color fidelity, although I
can't quote specs for either one. j
I suppose what I mean is: what about using Perfect Vision, LIVE!, etc, in
leiu of DigiView. For instance, why couldn't you use Perfect Vision (or
LIVE!, etc) with a camcorder (or camera) to capture a still image
(photograph, landscape, etc). You could use the same device to capture
'real-time' video. (I gather that is their main purpose) In short, two
functions in one device. It would beat buying both DigiView and a frame
grabber? — The concern I have, and questions are: is the resolution of
Perfect Vision, LIVE!, etc as high as DigiView? With DigiView you have a
maximum 400 lines vert resolution, but a television signal has 500+ lines.
Does this mean that frame grabbers have higher res? (and how the heck do
they compress 500+ lines into 200 or 400 for Amiga display?) — not trying
to be picky, just curious, and boy! is this stuff getting expensive…
thanks… –jp–
Sure, you could use Live! to grab a pic on-the-fly. I dunno about Perfect
Vision, though, haven't been out with one. As far as rez lines, they're
separate from the number of scanning lines. The NTSC system has exactly 525
scan lines per frame, and that's a fixed value in the States. The number of
rez lines refers to how closely sd individial picture details can be before
the camera is unable to distinguish them as separate lines. If you've ever
seen the "Indian Head" test pattern (also called a wedge chart), you may
remember wedges of lines that start out broadly spaced at one end and
converge into a closely spaced blur of lines at the other. These are used
to measure lines of resolution. There are calibrated points on the wedge
(400, 300, 200, etc). When viewing the wedge thru a camera, one looks at
the point on the wedge where the individual lines merge into a blur, and
the number next to that point corresponds to the camera's (and system's)
lines of resolution. Another way to look at it… if a camera only had,
say, 10 vertical lines of resolution, a pin-striped suit would appear as a
solid color on camera. But if the camera's resolution spec was above the
spacing of the pinstripes, they would show as individual stripes on
camera.
Yep, this gets expensive… and confusing! j
thanks for all the help. I'll just keep checking things out and
not bother you for a while… Will let you know if I find
something interesting… –jp–
thanks for all the help. I'll just keep checking things out and
not bother you for a while… Will let you know if I find
something interesting… –jp–
Just thought I`d throw in my 2 cents worth for the guy and others that get
confused when hearing about TV resolution!
The Vertical resolution of a broadcast NTSC signal is limited too about 330
lines of vertical resolution. The NTSC signal contains 525 horizontal scan
lines but these are different than the vertical lines that are used to rate
different video products. Vertical resolution is the number of VERTICAL lines
that a TV, VCR, CAMERA can display/record before they begin to blur together.
A plain TV and VHS sets can only show about 240 lines of vert res. One of
the 'Monitor' type of TV sets (ones that claim 330 to 560 or more) or the
only ones where you actually see the full quality of broadcast (330 lines)!
Beta VCR's have a slightly better resolution (about 250) than VHS.
Then theres ED BETA (ED for Extended Definition) and S-VHS (Super VHS) that
can record over 400 lines of ver. res. Of course your source has to provide
that many lines. So then you'll only get 330 lines if your broadcast signal
is ideal. Now there are S-VHS camcorders (maybe ED Beta camcorders too?) that
will allow you to record better than broadcast! Another catch is you need a
Monitor set that will take the seperated chroma and luma signals so you'll see
all those lines! (Luckily the Commodore monitors have those seperated inputs!)
While I'm here…the 8mm video format is capable of 330 lines BUT they haven't
found a way to cost effectively manufacture a tape that will do the job so they
are limited to about 240-260 ver. lines. Oh, theres a new video format coming
this fall, it will be 8mm Hi-Band! Supposedly over 400 lines too!
Then sooner or later there will be HDTV (High Definintion TV!) (600-1200 lines!)
I have no idea what the resolution is on the 1080,1084,2002 monitors but the
resolution of the video signal must be at least 330 lines in order to get the
broadcast quality needed for Desktop Video! So remember, if you use a plain
Beta, or VHS ,or 8mm you'll lose a lot in quality but its more than adequate
for home use.
By the way…a VHS with HQ (High Quality circuits) does NOT add any apparent
Opps! Last paragraph was meant ot read: The output of the Amiga thru a
genlock must be at least 330 lines in order for it to be of use in Desktop
Video applications!
Does anyone know what the output vertical res is???
Opps! Last paragraph was meant ot read: The output of the Amiga thru a
genlock must be at least 330 lines in order for it to be of use in Desktop
Video applications!
Does anyone know what the output vertical res is???
Just thought I`d throw in my 2 cents worth for the guy and others that get
confused when hearing about TV resolution!
The Vertical resolution of a broadcast NTSC signal is limited too about 330
lines of vertical resolution. The NTSC signal contains 525 horizontal scan
lines but these are different than the vertical lines that are used to rate
different video products. Vertical resolution is the number of VERTICAL lines
that a TV, VCR, CAMERA can display/record before they begin to blur together.
A plain TV and VHS sets can only show about 240 lines of vert res. One of
the 'Monitor' type of TV sets (ones that claim 330 to 560 or more) or the
only ones where you actually see the full quality of broadcast (330 lines)!
Beta VCR's have a slightly better resolution (about 250) than VHS.
Then theres ED BETA (ED for Extended Definition) and S-VHS (Super VHS) that
can record over 400 lines of ver. res. Of course your source has to provide
that many lines. So then you'll only get 330 lines if your broadcast signal
is ideal. Now there are S-VHS camcorders (maybe ED Beta camcorders too?) that
will allow you to record better than broadcast! Another catch is you need a
Monitor set that will take the seperated chroma and luma signals so you'll see
all those lines! (Luckily the Commodore monitors have those seperated inputs!)
While I'm here…the 8mm video format is capable of 330 lines BUT they haven't
found a way to cost effectively manufacture a tape that will do the job so they
are limited to about 240-260 ver. lines. Oh, theres a new video format coming
this fall, it will be 8mm Hi-Band! Supposedly over 400 lines too!
Then sooner or later there will be HDTV (High Definintion TV!) (600-1200 lines!)
I have no idea what the resolution is on the 1080,1084,2002 monitors but the
resolution of the video signal must be at least 330 lines in order to get the
broadcast quality needed for Desktop Video! So remember, if you use a plain
Beta, or VHS ,or 8mm you'll lose a lot in quality but its more than adequate
for home use.
By the way…a VHS with HQ (High Quality circuits) does NOT add any apparent
Sure, you could use Live! to grab a pic on-the-fly. I dunno about Perfect
Vision, though, haven't been out with one. As far as rez lines, they're
separate from the number of scanning lines. The NTSC system has exactly 525
scan lines per frame, and that's a fixed value in the States. The number of
rez lines refers to how closely sd individial picture details can be before
the camera is unable to distinguish them as separate lines. If you've ever
seen the "Indian Head" test pattern (also called a wedge chart), you may
remember wedges of lines that start out broadly spaced at one end and
converge into a closely spaced blur of lines at the other. These are used
to measure lines of resolution. There are calibrated points on the wedge
(400, 300, 200, etc). When viewing the wedge thru a camera, one looks at
the point on the wedge where the individual lines merge into a blur, and
the number next to that point corresponds to the camera's (and system's)
lines of resolution. Another way to look at it… if a camera only had,
say, 10 vertical lines of resolution, a pin-striped suit would appear as a
solid color on camera. But if the camera's resolution spec was above the
spacing of the pinstripes, they would show as individual stripes on
camera.
Yep, this gets expensive… and confusing! j
I suppose what I mean is: what about using Perfect Vision, LIVE!, etc, in
leiu of DigiView. For instance, why couldn't you use Perfect Vision (or
LIVE!, etc) with a camcorder (or camera) to capture a still image
(photograph, landscape, etc). You could use the same device to capture
'real-time' video. (I gather that is their main purpose) In short, two
functions in one device. It would beat buying both DigiView and a frame
grabber? — The concern I have, and questions are: is the resolution of
Perfect Vision, LIVE!, etc as high as DigiView? With DigiView you have a
maximum 400 lines vert resolution, but a television signal has 500+ lines.
Does this mean that frame grabbers have higher res? (and how the heck do
they compress 500+ lines into 200 or 400 for Amiga display?) — not trying
to be picky, just curious, and boy! is this stuff getting expensive…
thanks… –jp–
That gizmo you saw was the same thing, I think. It can disassemble any NTSC
source (camera or tape playback) but you still have to make 3 passes, as
the output of this gadget has R,G,B as separate signals. These RGB signals
"look" like a single camera output with the filter wheel in front of it. As
far as "bypassing" Digi-View, I don't quite follow. You still need to do
an annalog-to-digital conversion somewhere along the line. If you had a
standalone framegrabber, you're still left with the task of getting the
"grabbed" frame into digital format. The "other" digitizer, Amiga Live!,
does both of these functions. Personally, I think Digi-View has better
results than Live!, in terms of rez & general color fidelity, although I
can't quote specs for either one. j