3-chip really better than 1-chip cams?

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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?

 

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On a sunny day (4 Feb 2005 01:28:18 -0800) it happened "Lisa Horton"
<The2ndspiketoo@webtv.zzn.com> wrote in
<1107509298.476310.317230@z14g2000cwz.googlegroups.com>:

>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?
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?

 

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"Jan Panteltje" <pNaonStpealmtje@yahoo.com> wrote in message
news:1107606190.466c0ed3eed74e44ca1949f28453efe3@teranews...
>
> 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?
>
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

 

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"David McCall" wrote ...
> 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?

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.

 

[Duff]

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On 4 Feb 2005 01:28:18 -0800, "Lisa Horton"
<The2ndspiketoo@webtv.zzn.com> wrote:

>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?

No experience myself, but was it a low light (night time) shot?

 

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"Lisa Horton" wrote:
> 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?

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.

 

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"Richard Crowley" <rcrowley7@xprt.net> wrote in message
news:1109ppkickm3fa7@corp.supernews.com...
> "David McCall" wrote ...
>> 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?
>
> 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.
>
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

 

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"David McCall" wrote ...
> 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?

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.

> I think there were varifocal lenses available 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

 

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"Richard Crowley" <rcrowley7@xprt.net> wrote in message
news:110bd86i3guuc9b@corp.supernews.com...
> "David McCall" wrote ...
>> 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?
>
> 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.
>
>> I think there were varifocal lenses available 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
>
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

 

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"David McCall" wrote
> 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.

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.

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

You are welcome to be the resident expert of those old
things. I have enough on my hands with the current crop.

 

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"Richard Crowley" <rcrowley7@xprt.net> wrote in message
news:110c99se6u5dhb0@corp.supernews.com...
>
> You are welcome to be the resident expert of those old
> things. I have enough on my hands with the current crop.
>
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

 

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On a sunny day (Sat, 5 Feb 2005 22:11:17 -0800) it happened "Richard Crowley"
<rcrowley7@xprt.net> wrote in <110bd86i3guuc9b@corp.supernews.com>:

>
>
>"David McCall" wrote ...
>> 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?
>
>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
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.

 

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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.