[ale] OT: camcorder/camera combos

[aaron]

I think Eric's "Hi8 is analog" point was intended to help clarify the 
definitions and was simply pointing out that Standard8, Hi8 and Digital8 
are 3 different, independent signal and recording standards. Some 
confusion arises in that products like the Sony Digital8 camcorders blur 
the distinctions by supporting some functionality for all 3 standards of 
8mm video tape.

He was certainly correct in stating that the Hi8 format is entirely 
analog. The fact that Digital8 is recorded on the same kind of metal 
oxide tape cassettes as Hi8 or that a camcorder can play back or convert 
between both standards is irrelevant to that.

On a couple other points in the thread...

I liked the CCD explanations, and they prompted a trip to:
  http://www.howstuffworks.com/digital-camera.htm
...which also had some general answers to the original question:
  http://www.howstuffworks.com/digital-camera38.htm

Turns out the CCD descriptions were partly correct, but capacitive wells 
are just part of the picture (pun intended) with these solid state analog 
devices. The actual light sensitivity is provided by semi-conductor 
diodes and are fairly similar to photovoltaic cells.

Mostly the site confirmed what I knew already: that the resolution issues 
of video and dedicated digital still cameras touch on a lot of factors. I 
would be surprised to find many consumer Video cameras (for either 
digital or analog recording formats) that employed a capture chain 
producing more than 800x600 pixels, and I expect cost factors steer most 
to 640x480 because that resolution is most consistent with common 
standards for video signals and lossy digital encoding schemes.  [For 
those that may not know, the standard NTSC TV signal has a maximum, 
physical vertical resolution of 482 pixels. The Euro PAL TV standard is 
100 pixels better on usable vertical resolution, but the standard has a 
"resolution" trade off of 5 fewer frames per second.]  As a rule, the 
"still photo" features of consumer Video cameras will be adequate for 
small format prints and computer uses, but will not provide the 
photographically oriented resolution that can be found in dedicated 
digital still cameras.  As near as I can determine, a 640x480 resolution 
is roughly equivalent to a 1.6 "megapixel" rating on a still camera... 
but my searches for exact numbers only confirmed that the marketroid 
"megapixel" anti-standard value states the number of photo-sites on the 
CCD of a device, while the true physical pixel resolution, color depth 
and dynamic range of a device may only be loosely related to that number.

As with just about everything, as quality goes up so does the price. 
Industrial / Professional grade video cameras of higher cost and quality 
will employ a beam splitter to 3 CCD's of greater physical area and 
higher pixel counts, one CCD each for the RGB channels. As Eric also 
correctly noted, the optics make a HUGE difference, and the better video 
cameras employ true focus tracking 13 element zoom lenses made with 
dichroic glass. All these factors greatly improve the effective 
(interpolated) resolution, light sensitivity and color balance control of 
the camera's capture chain.  The last point of quality improvement with 
more professional digital cameras is the use of higher bandwidth 
recording formats with lower compression ratios (less than 5 to 1) that 
don't discard most of the captured information before it even hits the 
recording medium.

Of course, the biggest marketroid myth is that "Digital" is somehow, 
magically, always better quality, and in a whole lot of cases it simply 
is not. Recording signals in digital form requires several times the 
bandwidth of recording the same signals in analog, and there are a whole 
lot of compromises being made to cram that digital bandwidth onto 
increasing tiny formats. There are certainly a number of advantages to be 
found with digital signal recording and processing, but these still come 
at some cost.

---
Sorry for the overkill, but these are areas I know a fair amount about.

peace
aaron

On Thursday 12 December 2002 09:02, Geoffrey wrote:
> Okay, so we're picking nits off of nits here.  I'm a stickler for
> accuracy though so I'll throw out what the manual says and be done with
> it:
>
> With your digital camcorder, you can use Hi8/Digital8 video cassetes.
> Your camcorder records and plays back pictures in the Digital8 system.
> Also, you camcorder plays back tapes recorded in the Hi8/standard 8
> (analog) system.  You, however cannot use the functions in "Advanced
> Playback Operations" on page 52 to 58 for playback in the Hi8/standard
> 8 system.  To enable smooth transition, we recommend that you do not
> mix pictures recorded in the Hi8/standard 8 with the Digital8 system on
> a tape.
>
> Eric Webb wrote:
> > On Thursday 12 December 2002 02:15 am, Geoffrey wrote:
> >>>Are you on crack?  Hi8 is purely analog.  miniDV is purely digital.
> >>
> >>Ah, not exactly true.  My camera Sony trv730 is a digital camera but
> >>will accept either hi8 or standard 8 tapes.  With standard 8 tapes,
> >> you get analog recording.
> >
> > There's a whole lotta crack smokin' tonight.
> >
> > I have a TRV330 and 530 myself.  Read your manual again.  While these
> > cameras may use either tape medium, the recording is in Digital8
> > format.  All of these cameras (AFAIK) only PLAY the standard 8mm and
> > Hi8 analog formats -- they do not record in those formats.
> >
> > (Manual says that if you record on standard 8mm, you must play back
> > in same machine or you will get mosaic artifacting -- the fact that
> > it's a mosaic pattern alone tells you it's gonna record in digital
> > mode!  The cheaper standard 8mm tape doesn't have the resolution that
> > Digital8 requires.)
> >
> > http://www.epinions.com/content_27278413444
> >
> > And even if it did, the fact that your camera would record analog on
> > a standard 8 tape doesn't disprove my original statement.  It only
> > would mean that your camera supports multiple formats.
> >
> >
> > -E.
> > _______________________________________________
> > Ale mailing list
> > Ale at ale.org
> > http://www.ale.org/mailman/listinfo/ale
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