3-chip really better than 1-chip cams?

Discussion in 'Professional Video Production' started by Lisa Horton, Feb 4, 2005.

  1. Lisa Horton

    Lisa Horton Guest

    Are 3-chip cams really better than 1-chip cams? Side by side with the
    naked eye, I din't notice a whopping difference. Why exactly are the 2
    extra CCDs worth having?
     
    Lisa Horton, Feb 4, 2005
    #1
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  2. Asking that question here is a bit like going to a cooking
    newsgoup and saying "is butter really better than margarine?"
    Yes, there are lots of people who don't know (or care) about
    the difference and lots of times you can't tell the difference.
    But for critical applications, nothing beats the real thing.

    If you can't see the difference, then don't worry about and
    save your money. However, if you are doing serious shooting,
    and under less than perfect conditions, you might want to come
    back and compare them again.

    One-chip cameras generally suffer from poorer performance
    at low light levels, lower resolution, and compromised color
    rendering. These are all the result of sharing the imaging surface
    between all the different colors as contrasted with each color
    having its dedicated wall-to-wall pickup chip.

    Likely there are one-chip cameras that are quite nice (certainly
    under optimal conditions). But as the technology improves the
    performance of one-chip cameras, the same technology keeps
    3-chip cameras a couple steps ahead.

    In addition, one-chip cameras tend to be designed for lower
    price points which means that there are further compromises
    in video processing and options/features.

    For the same reason, they generally have lower-performance
    lenses, frequently lenses that are built-in and give you no option
    of replacement with better (or differently featured) glass.

    These are all sweeping generalities and I'm sure people can
    cite counter-examples to each of these statements. If you
    want something more concrete, you'd have to compare specific
    models, etc.
     
    Richard Crowley, Feb 5, 2005
    #2
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  3. In 1 CCD cameras the color information is obtained by some sort of colored
    pattern (stripe filters) on the CCD.
    This sets limits to the amount of detail in the color.
    If you play on a normal TV NTSC or PAL the color bandwidth is limited anyways..
    So maybe it is not so obvious (but you can see it).
    When you use 3 CCDs, one for each color, you get more signal, and more detail.
    The difficult part is that the CCDs have to be exactly aligned.
    Quality when using RGB (best) YUV (next best) Svideo (next) or composite (worst).
    You should also have some better signal to noise ratio with 3 CCDs perhaps.
    As pointed out it all depends on quality of color splitting prism, lenses,
    electronics, when you compare these 2 systems.

    Now all we need is 4 (four) CCD chips, and we can imitate them 4 tube BBC
    cameras....
    IIRC they use(d?) one extra for luminance only?
     
    Jan Panteltje, Feb 5, 2005
    #3
  4. Lisa Horton

    David McCall Guest

    RCA used to make a camera with 1 huge image orthicon and 3 videcon.
    The Image orthicon probably gave it a pretty good luminance signal, but
    I was never that fond of videcons.

    Does anybody remember if that camera had any solid state components,
    or was that still all tubes?

    David
     
    David McCall, Feb 5, 2005
    #4
  5. "David McCall" wrote ...
    Transistors were only a laboratory curiosity across the
    river in New Jersy at that time. It took a camera cable
    as big as your wrist and 3 or 4 six-foot racks full of fire-
    bottles back in the closet to support *each* camera. I
    don't think that color television would have been practical
    in the tube-era without the previous invention of
    refrigeration and air-conditioning. :)

    It was also the era of several (typically 4) prime lenses
    on a turret as zoom lenses weren't around yet.
     
    Richard Crowley, Feb 5, 2005
    #5
  6. Lisa Horton

    David McCall Guest

    The camera that I'm talking about was manufactured in the early 60s.
    I thought the transistor was born in the same year as me (1947).
    It is conceivable that they could have put some transistors in such
    a thing by then. We had transister radios by then, didn't we?

    I think there were varifocal lenses available then. The prime lenses
    were substantially better lenses though. The earliest ones couldn't
    hold focus over much of a range, so you used it as a lens that could
    be switched to multiple focal lengths, but you had to refocus after
    every change. I seem to remember that video cameras with this type
    of lens had their turrets removed and a bar went through the hole
    with the lens attached to one end and a handle at the other end.
    You changed the focal length by pulling or pushing on that handle.
    I think that rotating the handle adjusted the focus on some units.
    I've even seen some pretty old monochrome cameras with this rig.

    I also remember working with Arri and Éclair (SP?) 16mm cameras
    with 12 x 120 Angenieux zoom lenses durring that period too. I even
    think we had some manner of zoom on one of the B&W cameras we
    used for multi-camera glitch switched oferflow classrooms while I was
    in Junior High (1961?)

    David
     
    David McCall, Feb 6, 2005
    #6
  7. "David McCall" wrote ...
    Yes there were cameras (even tube cameras) that used transistors
    in the 1960s, but the old 4-tube (and 3-tube) image orthicon cameras
    (like RCA TK41) were from the previous decade...
    http://www.ev1.pair.com/colorTV/myTK41_2.html

    I believe they were into plumbicons, saticons, vidicons,
    etc. by the 1960s and the image orthicon was no longer
    being manufactured by then.
    Yes there were by the 1960s, but not back in the early
    1950s. Note the lens turrets on the front and the operator's
    rotating handle on the back in the photos on Kris Trexler's
    webpage cited above.

    Another interesting historic account at...
    http://www.novia.net/~ereitan/Color_Cameras.html
     
    Richard Crowley, Feb 6, 2005
    #7
  8. Lisa Horton

    David McCall Guest

    I belive I've at least seen a picture of a TK-41 with a zoom and push rod
    replacing the typical turret. The camera I'm talking about TK-42 which
    was shown at the 1962 NAB convention

    Here is a quote from
    http://www.kingoftheroad.net/colorTV/TVcams-in-action.html
    It is near the bottom of the page (search on TK-42 to ge there)
    There are also a number of great pictures of the older TK-41

    "Uh oh, a suitor waits in the wings! The TK-41 will soon be
    replaced by RCA's new TK-42 "M-channel" color camera.
    In addition to the three color (RGB) vidicon pickup tubes,
    the TK-42 adds an image orthicon monochrome fourth tube.
    Shown here is the TK-42X experimental camera and a
    TK-60 monochrome camera at the 1962 NAB convention."

    A little further down the page you will see this quote
    about updateded TK-41s with transistors :)

    "NBC's old TK-41's continued to produce superior pictures
    into the early 1970's, partially due to modified
    low-noise transistorized pre-amps."

    You may also have noted that the pictures of the TK-42s
    have Zoom lenses. Closer to the top, there is a picture
    of a TK-41 with a Zoom lens fitted. The zoom lenses are
    setup to work with normal handles rather than the earlier
    push rods that I described.

    I found the information toward the bottom of this page interesting too.
    They claim that the TK-42 was more transistorized than the TK-41.
    http://www.big13.net/Facilities/facilities_black_and_white_to_co.htm

    Here are some pictures of TK-42s in stations all through the 60s
    http://www.oldradio.com/archives/hardware/TV/tk42.htm

    It was the hot new camera for the 60s, but it didn't sell that well because
    the older TK-41 with 3 Image Orthicons were still making a better picture.
    That may be why Richard didn't have good information on this one. I was
    using B&W Image Orthicon cameras in the Army in 1969, and we were
    going through brand new Image Orthicon tubes like s__t through a goose.

    Ain't Google a wonderful thing.

    I don't mean to cut down Richard. He provides a lot of good information
    around here, Just not in this particular thread.

    David
     
    David McCall, Feb 6, 2005
    #8
  9. Now that brings back memories.
    I remember in 1968 when I started working in broadcasting in the Netherlands
    (Europe BTW) we still had some orthicon BW cameras..
    1967 They started color (PAL) and used Philips 3 tube plumbicon cameras.
    Vidicons were only used in some film editing tables.
    They were very fragile, sensitive to burn in, and plumbicons were not so
    affected by that.
    Those 3 plumbicon Philips cameras gave a great picture, and were all
    transistor.
    As for the big racks with tubes, I have done maintenance on the old Ampex
    VR1200 (or 1100?) quadruplex video recorders, it had transistors in the
    'colortec' and 'amtec' time base compensator, but the rest was tubes for a
    large part, we has 6 in a room and the temp would rise to over 30 degrees C....
    http://www.xs4all.nl/~levend/tvmuseum/tvmuseumedit/edit06.htm
    shows some of thse machines and my old workplace....
    Text is in Dutch, just look at the pics :)
    Later (seventies) video editing was done on Ampex AVR1 with RA4000 editing
    console, hehe those were all transistor, but HUGE machines.
    If something went wrong it would stretch the 2 inch tapes to a string...
    I still have a license for maintenance of AVR1 ....
    That machine was so complicated it took 11 kilo of books for the 3 weeks
    training, I remembered, it was excess weight on the flight ..
    It was clear to me that (as electronics person), that one day it would all be
    hand held and integrated in a chip... They would not believe me.
    I did not foresee digital though, that much compression (as mpeg2) was unheard
    of.
     
    Jan Panteltje, Feb 6, 2005
    #9
  10. Actually the one with the tubes was the VR1000, that I forget
    that after all these years, the big cabinet with the 2 doors
    holds the electronics with TUBES.
    The doors were always open.. heat, and connected at the top
    via a chimney for the hot air IIRC.
    This was a BW video recoding machine.
    http://www.lionlmb.org/quad/vr1000_1.jpg
    Six machines required 4 technicians round the clock to keep it
    running.
     
    Jan Panteltje, Feb 6, 2005
    #10
  11. "David McCall" wrote
    What they didn't mention is that the TK42, etc were so terrible
    that even the NBC studios in NY and Burbank wouldn't use them
    even though NBC was wholly owned subsidiary of RCA. RCA
    was forced for accellerate development of the TK-44 in face
    of massive defection of their customer base to Philips/Norelco.
    I believe even NBC Burbank managed to dump RCA during
    that time because they were farther from NY corporate HQ.
    You are welcome to be the resident expert of those old
    things. I have enough on my hands with the current crop. :)
     
    Richard Crowley, Feb 6, 2005
    #11
  12. Lisa Horton

    David McCall Guest

    Don't claim to be an expert, but I was sort-of there. I remember
    my mom getting me out of school to go to "educational" station
    in Tampa. I think it was WEDU (what we now call PBS). This
    would have been in while I was in elementary school . Anyway,
    it was probably pre 1960 and all B&W. I don't recall any tape
    equipment there, but they did have a kinescope. That was a
    very exciting trip for me. She was going up to be on a live talk
    show (I have no recollection what the show was about, but seeing
    all of the equipment was very cool.

    David
     
    David McCall, Feb 6, 2005
    #12
  13. Lisa Horton

    WEBPA Guest

    I am a recovering TK-42 victim. I was forced to shove one around KGNC-TV in
    Amarillo, Texas in 1966. It had the "machine gun grip" zoom and focus
    controls. Having started on a GE model ? with a 4:1 Zoomar controled by the
    twist & push rod down the middle of the turret handle, this was like a
    sex-change operation. Worse. For a while, I (and the other camera operator),
    had to grab the thing by the upper right and lower left of the case to do pans
    and tilts without unintentional zooms and focuses. The pedistal was not a
    problem, except that the pneumatic tires on mine kept going flat.

    Furthermore, our news set had a rear-projection background for chroma-keying
    graphics behind the "talent"; in order to get a hard, 100% blue acceptable to
    the Grass Valley Chroma Keyer (about 2 feet of 19" rack space), the background
    had to be a very, very intense grass green. Not just by eyeball, but by a
    MacBeth hand-held color-meter (this is NTSC, remember). This was a great
    marvel, and at one point, we had some expert from RCA visit Amarillo
    (punishment?) to analyze the phenomena. He left without comment or solution.

    To set-up this thing, the operator (me) and the engineer at the console (?
    Jack?) had to cooperate for about 15 minutes, tweaking this pot and that. The
    main problem was that the set-up changed when you closed the side doors.
    Possibly due to the blast of hot air (like opening an oven before Thanksgiving
    dinner) you got when opening a warmed-up camera.

    There is more but I already see yawns out there.

    Good old days! Right.


    p a w e b e r @ a o l . c o m


    webpa
     
    WEBPA, Feb 9, 2005
    #13
  14. And those phenomenon are the source of the story of the
    Blue Banana (whether true or apocryphal.)

    Basically, back in the early days of color TV when the
    camera setup location was quite far away from the studio,
    a prankster sneaked into the studio and substituted a blue-
    painted banana for the yellow one in the fruit bowl they
    were using for color shading adjustments. The shading
    engineer couldn't figure out why all the other fruit looked
    wrong when he got the banana to be a nice shade of yellow,
    and vice-versa.

    And then there is the story of the origin of the phrase
    "ready when you are, CB". (Cecil B. DeMille and the
    shooting of "The 10 Commandments" with Charlton "Mo"
    Heston, etc.)
     
    Richard Crowley, Feb 9, 2005
    #14
  15. Lisa Horton

    PTRAVEL Guest

    Well? Let's have it!
     
    PTRAVEL, Feb 9, 2005
    #15
  16. Cecil B. DeMille has a dozen cameras set up for parting of the Red Sea
    scene. A dozen cameras are needed because it is going to be a "one take
    wonder"................
    All the movie heads are there. The press is there, hovering around Cecil B.
    There is literally a cast of thousands waiting for their cue.
    The dozen cameras have been carefully positioned on the beach, on the bluff
    over looking the beach, on boats out on the water, down in the valley and
    one right in front of Cecil B. DeMille.

    Cecil B. stands up.
    There is a hush...........

    He puts the megaphone to his lips and yells.........
    Rrrrrrrroll ze CAMERAS!!!!!!
    A moment passes................ and then......
    ACTION! ACTION! ACTION!!!!
    Suddenly, all hell breaks loose.
    The FX guys have the waters held back. (this ain't reality, kids. This is a
    joke... remember?)
    Egyptians on foot, on horseback and in chariots come roaring over the hill.
    The cameras on cranes boom up.
    The Egyptians race to the beach and into the liquid canyon where the
    Israelites have passed.
    Some cameras dolly left.
    Some cameras boom down.
    EVERYONE is on their feet.
    The FX guys release the water.
    The chasm begins to fill.
    Cecil B. DeMille is screaming through the megaphone at the top of his lungs,
    spouting brilliant spur of the moment directions to the actors and cameras.
    The camera assigned to close-ups hit their marks.
    It looks like all the extras in Egyptian costumes ain't gonna make it to the
    payroll hut at sunset.
    But no........... everyone knows their script. Everyone is safe.
    The scene is a cinematic triumph for Cecil B.
    There is a lot of hand shaking and back slapping going on where the studio
    folks are gathered.
    Then Mr. DeMille puts down the megaphone and .................

    .................. Ok Richard......... you take it from here................

    (Ain't I a stinker?)

    Bill F.
     
    Bill Farnsworth, Feb 9, 2005
    #16
  17. "PTRAVEL" wrote ...
    So the story goes that this happened in on location in the desert
    somewhere in Egypt during the shooting of "The Ten Commandments"
    direced by Cecil B. Demille. Charlton Heston played Mo, and
    Yul Brynner played the Pharoah, etc.
    Details at http://us.imdb.com/title/tt0049833/combined

    In the big, epic scene, the Hebrew slaves were are all assembled
    for their little 40-year trek back to the Cannan, the Promised Land.
    Now this is the scene for which the term "cast of thousands" was
    invented. Uncounted local extras dressed in period garb, with lots
    of livestock and wagons, carts, etc.

    Normally, feature films are shot with a single camera so that each
    shot/scene can be meticulously blocked, dressed, and lit as close
    to perfection as the time/budget will allow.

    However, for a big expensive scene like this, or for a non-repeatable
    scene (like blowing up something!), they use multiple cameras, more
    like TV-style shooting. For this particular scene, they are reputed to
    have used four units (crews associated with a single camera).

    The first unit was the Director of Photography up on the big Chapman
    crane with Cecil himself in the second chair. Second and third units
    were cameras down among the assembled throng/animals/rollingstock,
    etc. And the fourth unit was getting the wide shot from up on a bluff a
    few hundred feet away.

    When everything was ready, Cecil gave a nod to his assistant who
    signaled the PAs to start the background (crowd movement, etc.)
    Then when just the right amount of dust was billowing, they called
    the signal to roll the cameras.

    Extras marched, flocks roamed, children ran around, oxcarts rolled,
    etc. etc. etc. for several glorious minutes until everyone was out of
    blocking distance and then the director called "CUT!"

    But something had gone wrong. The DP turned to Mr. DeMille and
    confessed that he didn't get the whole scene because the film had
    broken in the camera sometime during the scene. Since the production
    was done in Mitchell Vista Vision where the film moves horizontally,
    it was likely moving along at a pretty good clip.

    Alas the second unit also reported a problem. Some of the desert
    sand got into the works and stripped a gear. The camera would have
    to go back to Hollywood for repair.

    But the third unit had the worst excuse of all. Those big old film
    cameras had a mechanism where you could crank the body to the
    right so you could see through the viewfinder tube through to the
    lens (to frame & focus, etc.), but then you had to remember to
    crank it back over so that the film gate was in front of the lens.
    (Now, they have a mirror on the shutter so that you can see
    through the lens during the closed interval while the film is
    moving.)

    Well, being the third-string, the camera assistant forgot to crank
    the camera back and they didnt expose ANY film! Mr. DeMille
    made sure his assistant noted the names of the crew who would
    never work in Hollywood again if he had anything to do with it.

    By this time DeMille was beside himself at the failure of three
    of of his four camera units for this huge, expensive scene. He
    ordered his assistant to use his megaphone and shout to the 4th
    unit up on the bluff to see if at least THEY had got some usefull
    footage. It took a couple of tries to get their attention and then
    to hear the faint reply...

    "Ready when you are, C.B.!"
     
    Richard Crowley, Feb 9, 2005
    #17
  18. Gee, that one's better than the version I heard. But the punch
    line is approximately the same. See my other posting for the
    alternate tale! :)
     
    Richard Crowley, Feb 9, 2005
    #18
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