When roughly did television studios change from TV cameras with a turret
of fixed-focal-length lenses to those with zoom lenses? Was the change initially partial, with a studio having mainly turret cameras but with a
zoom camera for those shots that needed it (*)? Could any existing
cameras have the turret removed and a zoom lens attached in its place,
or did the change to zoom lenses generally happen only when older
cameras were replaced with newer ones?
Did turret lenses have a common focus control, so a cameraman could
change from one lens to another (obviously not while they were live to
air) and be reasonably confident that the subject would still be in
focus, with only minor tweaks being needed?
I presume the changeover from turret to zoom happened when zoom lenses
could be made that gave equivalent picture quality (sharpness, minimal pincushion/barrel distortion, wide maximum aperture), driven by the
greater convenience of not having to dolly cameras in/out (with the
resulting change in perspective and the need to follow-focus) in order
to home-in on a detail in the picture or to pull back to reveal the
wider picture.
(*) Equivalent to the use of radio mikes which initially gave worse
sound quality than boom mikes but were justified if they allowed a wide
shot where a boom mike would be seen in-shot.
When I worked in studios on b/w cameras, late '50s early '60s zooms were rarely used in studios and occasionally on OBs. The turret didn't have to
be removed, the zoom fitted in place of one of the fixed lenses but with additional hardware to support the weight because the zooms were massive.
I think cameras with built in zooms only appeared with colour (bIcbw).
Did turret lenses have a common focus control, so a cameraman could
change from one lens to another (obviously not while they were live to
air) and be reasonably confident that the subject would still be in
focus, with only minor tweaks being needed?
Focus on b/w cameras was done by moving the pickup tube back and forth,
the lens being fixed focus. The add-on zooms had their own focus control.
I presume the changeover from turret to zoom happened when zoom lenses
could be made that gave equivalent picture quality (sharpness, minimal
pincushion/barrel distortion, wide maximum aperture), driven by the
greater convenience of not having to dolly cameras in/out (with the
resulting change in perspective and the need to follow-focus) in order
to home-in on a detail in the picture or to pull back to reveal the
wider picture.
A common fault with the bolt-on zooms was vignetting - darker in the
corners of the picture than in the centre.
On Fri, 13 May 2022 12:05:51 -0000 (UTC), The Other John
<nomail@home.org> wrote:
When I worked in studios on b/w cameras, late '50s early '60s zooms were >>rarely used in studios and occasionally on OBs. The turret didn't have to >>be removed, the zoom fitted in place of one of the fixed lenses but with >>additional hardware to support the weight because the zooms were massive.
I think cameras with built in zooms only appeared with colour (bIcbw).
The Pye image orthicon cameras had motorised turrets, so the operator
only had to push a little switch instead of turning a mechanical
handle. When we fitted a zoom to one of those we had to remember to
disable it with an internal switch in case the lens change switch was
pressed accidentally and burned out the motor.
The reason I was told for fitting zoom lenses to colour cameras was to maintain colour lineup. Different glassware could have slightly
different tints that wouldn't be a problem if the camera kept the same
lens, but would be noticeable if they were changed.
Rod.
I imagine the camera would have had to be mounted further back than
normal so it didn't continually try to tilt forwards.
I'd have thought that it would have been easier to
make the lenses move internally, as on a still or cine camera, rather than >moving the tube and the deflection coils without jogging them and getting >microphonic artefacts. Would the correct tube position for one lens have
been the correct one for another lens, or would the camera have to be >refocussed when changing lens?
When I worked in studios on b/w cameras, late '50s early '60s zooms were >rarely used in studios and occasionally on OBs. The turret didn't have to
be removed, the zoom fitted in place of one of the fixed lenses but with >additional hardware to support the weight because the zooms were massive.
I think cameras with built in zooms only appeared with colour (bIcbw).
I saw a very long focal-length zoom (not sure what its wide-angle setting was, but it was designed for greater magnification than normal at the telephoto end) and it was a big bugger - it looked to be about 6 feet long, so, given the large diameter lenses in it, it would have been very heavy. I imagine the camera would have had to be mounted further back than normal so it didn't continually try to tilt forwards.
Really. I remember I had a colour camera made by Hitachi. It had a serious >weird effect in very bright sun. IE on changes in contrast edges even when
in focus, you tended to get a kind of yellow fringe around things. In kind
of normal dull cloudy days it did not occur. Not sure what sensor it had in >it, but it was not a ccd, but a proper tube of some sort, though with very >little smearing you used to get with videcons. I'm going back a bit to the >late 70s early 80s, when I could still see here.
Brian
Really. I remember I had a colour camera made by Hitachi. It had a serious weird effect in very bright sun. IE on changes in contrast edges even when
in focus, you tended to get a kind of yellow fringe around things. In kind
of normal dull cloudy days it did not occur. Not sure what sensor it had
in it, but it was not a ccd, but a proper tube of some sort, though with
very little smearing you used to get with videcons. I'm going back a bit
to the late 70s early 80s, when I could still see here.
(*) Equivalent to the use of radio mikes which initially gave worse sound
quality than boom mikes but were justified if they allowed a wide shot
where
a boom mike would be seen in-shot.
The radio link was actually pretty good, it used an Eddystone FM tuner
which the firm had specially modified to cover the radio mic
frequencies. (Model S890 or S890/1). The sound quality limitation was
in the microphones they could use, as good quality microphones were too
big to conceal about the person.
The BBC research Department did tests on a lot of different microphones
and established that small crystal 'lapel' mics would be adequate in the circumstances. Anyone who has used one of those mics will appreciate
its limitations. The earliest transmitters used hearing aid valves,
which gave a remarkably good performance considering their low power consumption.
On Fri, 13 May 2022 at 16:45:06, "Brian Gaff (Sofa)" <briang1@blueyonder.co.uk> wrote (my responses usually FOLLOW):
Really. I remember I had a colour camera made by Hitachi. It had a serious >>weird effect in very bright sun. IE on changes in contrast edges even when >>in focus, you tended to get a kind of yellow fringe around things. In kind >>of normal dull cloudy days it did not occur. Not sure what sensor it hadIf it wasn't a CCD, it was probably three (for amateur use) tubes; colour haloing in bright conditions was, I think, caused by one of the tubes
in
it, but it was not a ccd, but a proper tube of some sort, though with very >>little smearing you used to get with videcons. I'm going back a bit to the >>late 70s early 80s, when I could still see here.
Brian
hitting its limit (the video equivalent of clipping in audio -
saturation?) before the others did.
(I don't _think_ any tube cameras used many tiny multicoloured filters -
or stripes - to get colour our of a single tube; I think the syncing -
plus, memory aspects in those days - would have been too horrendous. But I may be wrong.)
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1prws0m.117rqbt1qstwsgN%liz@poppyrecords.invalid.invalid...
(*) Equivalent to the use of radio mikes which initially gave worse sound >> quality than boom mikes but were justified if they allowed a wide shot
where
a boom mike would be seen in-shot.
The radio link was actually pretty good, it used an Eddystone FM tuner which the firm had specially modified to cover the radio mic
frequencies. (Model S890 or S890/1). The sound quality limitation was
in the microphones they could use, as good quality microphones were too
big to conceal about the person.
The BBC research Department did tests on a lot of different microphones and established that small crystal 'lapel' mics would be adequate in the circumstances. Anyone who has used one of those mics will appreciate
its limitations. The earliest transmitters used hearing aid valves,
which gave a remarkably good performance considering their low power consumption.
I remember one of my early Blue Peter Annuals from the late 60s or early 70s had a chapter on "how television is made" and there was a photo of John Noakes with what looked like the business end (capsule) of a hand-held mike on a heavy-duty string round his neck, connected to the big amp and transmitter in his back pocket, with the explanation that radio mikes were not used unless they really had to because the director wanted an especially wide shot. Things have progressed a bit since then, with tiny cylindrical mikes that clip to your tie, complete with a mini-Dougal (Dougal pup?) hairy windshield if used outdoors. And they can be hidden from view when used in drama, to allow a wide shot of actors having a conversation, with no boom anywhere. But when I last saw a drama being filmed (Lewis, in about 2005) they still used analogue comms back to the sound mixer. I got chatting to
the sound guy between scenes and he said that analogue still worked well and you didn't need to account for any digital encoding/decoding delays when syncing with the film, but they were prone to interference. And sure enough
a few minutes later he made a cut-throat gesture at the director who yelled "Cut. Reset. Let's go again. Dick's just picked up the radio of the taxi
that went past".
If it wasn't a CCD, it was probably three (for amateur use) tubes;
colour haloing in bright conditions was, I think, caused by one of the
tubes hitting its limit (the video equivalent of clipping in audio - saturation?) before the others did.
(I don't _think_ any tube cameras used many tiny multicoloured filters -
or stripes - to get colour our of a single tube; I think the syncing -
plus, memory aspects in those days - would have been too horrendous. But
I may be wrong.)
On Fri, 13 May 2022 at 16:45:06, "Brian Gaff (Sofa)" <briang1@blueyonder.co.uk> wrote (my responses usually FOLLOW):
Really. I remember I had a colour camera made by Hitachi. It had a serious >>weird effect in very bright sun. IE on changes in contrast edges even when >>in focus, you tended to get a kind of yellow fringe around things. In kind >>of normal dull cloudy days it did not occur. Not sure what sensor it hadIf it wasn't a CCD, it was probably three (for amateur use) tubes; colour haloing in bright conditions was, I think, caused by one of the tubes
in
it, but it was not a ccd, but a proper tube of some sort, though with very >>little smearing you used to get with videcons. I'm going back a bit to the >>late 70s early 80s, when I could still see here.
Brian
hitting its limit (the video equivalent of clipping in audio -
saturation?) before the others did.
(I don't _think_ any tube cameras used many tiny multicoloured filters -
or stripes - to get colour our of a single tube; I think the syncing -
plus, memory aspects in those days - would have been too horrendous. But I may be wrong.)
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf
If it's not on fire, it's a software problem.
On 13/05/2022 21:04, J. P. Gilliver (John) wrote:
If it wasn't a CCD, it was probably three (for amateur use) tubes;
colour haloing in bright conditions was, I think, caused by one of the
tubes hitting its limit (the video equivalent of clipping in audio -
saturation?) before the others did.
(I don't _think_ any tube cameras used many tiny multicoloured filters -
or stripes - to get colour our of a single tube; I think the syncing -
plus, memory aspects in those days - would have been too horrendous. But
I may be wrong.)
My first camcorder, a Philips branded Panasonic NV-M1, had a striped
filter on the single Newvicon tube. The filters were, IIRC cyan and
magenta, with a clear stripe between them to give a mono signal, BICBW, to make the tube more sensitive than RGB filtering, and the electronics
encoded the RGB components directly from that (Actually red, blue and
mono, as that was that was recorded on a VHS cassette. Green was obtained
by subtracting the Red and Blue from the mono.). Smaller, lighter, and a *lot* cheaper than the 3 tube setup, as well as being more robust. It used
a full size VHS cassette, and the reason I bought it was the fact is used
the same batteries as my Panasonic cellphone. It gave very acceptable results.
The first 3 sensor amateur cameras I saw were when CCD chips started being used and video went digital, and that was right at the top end of the
market. I still have one here in working order, and it uses a tiny 4
Gigabyte hard drive, which fits in a Compact Flash socket. At the time,
the available CF cards were less than a gigabyte, very expensive per megabyte, and 4 GB in the same space was spectacular.
--
Tciao for Now!
John.
"J. P. Gilliver (John)" <G6JPG@255soft.uk> wrote in message news:NubDMoJ9mrfiFw5n@a.a...
On Fri, 13 May 2022 at 16:45:06, "Brian Gaff (Sofa)"
<briang1@blueyonder.co.uk> wrote (my responses usually FOLLOW):
Really. I remember I had a colour camera made by Hitachi. It had a >>>seriousIf it wasn't a CCD, it was probably three (for amateur use) tubes; colour
weird effect in very bright sun. IE on changes in contrast edges even >>>when
in focus, you tended to get a kind of yellow fringe around things. In >>>kind
of normal dull cloudy days it did not occur. Not sure what sensor it had >>>in
it, but it was not a ccd, but a proper tube of some sort, though with >>>very
little smearing you used to get with videcons. I'm going back a bit to >>>the
late 70s early 80s, when I could still see here.
Brian
haloing in bright conditions was, I think, caused by one of the tubes
hitting its limit (the video equivalent of clipping in audio -
saturation?) before the others did.
(I don't _think_ any tube cameras used many tiny multicoloured filters -
or stripes - to get colour our of a single tube; I think the syncing -
plus, memory aspects in those days - would have been too horrendous. But
I may be wrong.)
I remember looking into video cameras when I worked in the school's audio visual room as my prefect duty in the sixth form (a really cushy number, getting to play with someone else's expensive kit, instead of having to
break up playground fights or keep order in the dinner queue). And there
were two categories: single tube with a striped filter and three tube with
a prism. The latter were bigger and more expensive: they produced better pictures but were more prone to the tubes getting out of registration.
Even nowadays, many cheaper cameras, both consumer and professional, have
a single CCD sensor and a stripe filter - and others are sold as "3 CCD".
I believe some professional tube cameras had *four* tubes: three for the colours and a separate one for the luminance rather than deriving it from (approx) 30:60:10 percent proportions of RGB.
NY <me@privacy.invalid> wrote:
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message
news:1prws0m.117rqbt1qstwsgN%liz@poppyrecords.invalid.invalid...
(*) Equivalent to the use of radio mikes which initially gave worse
sound
quality than boom mikes but were justified if they allowed a wide shot
where
a boom mike would be seen in-shot.
The radio link was actually pretty good, it used an Eddystone FM tuner
which the firm had specially modified to cover the radio mic
frequencies. (Model S890 or S890/1). The sound quality limitation was
in the microphones they could use, as good quality microphones were too
big to conceal about the person.
The BBC research Department did tests on a lot of different
microphones
and established that small crystal 'lapel' mics would be adequate in
the
circumstances. Anyone who has used one of those mics will appreciate
its limitations. The earliest transmitters used hearing aid valves,
which gave a remarkably good performance considering their low power
consumption.
I remember one of my early Blue Peter Annuals from the late 60s or early
70s
had a chapter on "how television is made" and there was a photo of John
Noakes with what looked like the business end (capsule) of a hand-held
mike
on a heavy-duty string round his neck, connected to the big amp and
transmitter in his back pocket, with the explanation that radio mikes
were
not used unless they really had to because the director wanted an
especially
wide shot. Things have progressed a bit since then, with tiny cylindrical
mikes that clip to your tie, complete with a mini-Dougal (Dougal pup?)
hairy
windshield if used outdoors. And they can be hidden from view when used
in
drama, to allow a wide shot of actors having a conversation, with no boom
anywhere. But when I last saw a drama being filmed (Lewis, in about 2005)
they still used analogue comms back to the sound mixer. I got chatting to
the sound guy between scenes and he said that analogue still worked well
and
you didn't need to account for any digital encoding/decoding delays when
syncing with the film, but they were prone to interference. And sure
enough
a few minutes later he made a cut-throat gesture at the director who
yelled
"Cut. Reset. Let's go again. Dick's just picked up the radio of the taxi
that went past".
Yes, I had breakthrough from a police car during a live stsge show. The fairy who had been fitted with the radio mic, carried on regardless but
the producer nearly had a fit!
I've just remembered a bit more about the Eddystone S890: Because the
radio mic transmitters drifted, the receiver was fitted with
extra-strong AFC. This was done by an auxiliary ferrite-cored inductor
in parallel with the main tuning coil, physically mounted in the
magnetic gap of a modified P.O. 2000-type relay. The relay coil was in
the anode circuit of an EF91 which was controlled by the F.M. detector.
As the anode current increased, the ferrite saturated and the inductance
of the auxiliary inductor reduced.
--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
"Brian Gaff (Sofa)" <briang1@blueyonder.co.uk> wrote in message news:t5lue6$8gh$1@dont-email.me...
Really. I remember I had a colour camera made by Hitachi. It had a
serious weird effect in very bright sun. IE on changes in contrast edges
even when in focus, you tended to get a kind of yellow fringe around
things. In kind of normal dull cloudy days it did not occur. Not sure
what sensor it had in it, but it was not a ccd, but a proper tube of some
sort, though with very little smearing you used to get with videcons. I'm
going back a bit to the late 70s early 80s, when I could still see here.
I think by the late 70s and early 80s, many consumer cameras had changed
from vidicons to plumbicons/saticons, though almost invariably a single
tube with a vertical RGB stripe to sense the different colours, and some means of de-multiplexing the camera output to separate into RGB colours.
High contrast didn't do any favours to tube cameras. I've even seen
broadcast cameras that produced horrible effects. One of the most
pronounced was in the TV adaptation of R F Delderfield's "To Serve Them
All My Days" from 1980 which was shot almost entirely on video, apart from some filmed scenes on a remote moorland. The shots of the public school
where most of the action occurred were mostly very good quality, but there were also shots of trains arrived at or departing from the local railway station, and of the seaside where the protagonist met his first wife.
Those station and seaside shots had lurid vibrant canary-yellow (!!) skies
or an unnaturally pale, washed-out blue that is never seen in real life. I presume the camera couldn't handle the fact that the sky was so much
brighter than the rest of the scene that they had exposed for, and reacted with bizarre colour casts.
There was a programme the other day about Morecambe and Wise, and there
was an excerpt from an archive interview on Pebble Mill at One. The bright exterior seen through the window, reflecting off bright concrete outside, caused a nasty green halo across M's and W's dark suits. (*)
Tube cameras were notorious for lag and smear: you often saw it if a
bright candle flame was seen in a studio-based drama: as the flame
flickered there was a coloured after-image which lasted several seconds.
And programmes like Top of the Pops, which often had low camera angles
that happened to "see" the studio lights, often led to a streaky
after-image as the camera panned across the light.
Modern solid-state (CCD or CMOS) cameras are pretty much bomb-proof to
that, so you don't see it any more. You might get people's faces with featureless white or orange patches where the brighter parts have caused
one or all of the colours to max-out, but at least there's no after-image. Gone are the days of early tube-camera ENG when a news report happened to catch a photographer's flash pointed at the lens, and the rest of the
report had a coloured rectangle at that point in the frame which very gradually faded.
For *really* bad overexposure artefacts, you have to go back further into history to the days of image orthicons. They produced a lovely crisp,
clean (not muddy, like a vidicon) image, but they went seriously loopy if part of the image was overexposed. Around a very bright object you got a
big black halo which made the correctly-exposed part of the image nearby darker in that area than it was elsewhere. I believe a very dark area
against a lighter grey produced the opposite effect: a whiter halo around black patch which extended into the mid-grey part of the subject. I'm sure someone will be along to explain the technicalities of localised electron depletion on the camera's sensor better than I could ;-)
(*) https://i.postimg.cc/G3BLKv9S/vlcsnap-2022-04-11-14h17m19s129.png is a still. For the benefit of Brian, Morecambe is wearing a brown jacket and
has a white hanky in his breast pocket. Wise is wearing a dark blue
jacket, a light grey shirt and a dark blue tie. Between them is a patch of overexposed white concrete from the building seen through the window.
There are green ghost patches to the right of M's tie-clip mike and his hanky, a very wide and really obnoxious green band about 20 pixels wide (almost 3% of the picture width) on W's sleeve to the right of the bright concrete, and fainter patches where even his light grey shirt has caused coloured banding on his dark tie. That camera really didn't like the sharp edges of light/dark contrast ;-) I imagine the interview dated from the
early 80s - 1984 at the very latest, for obvious reasons :-(
I remember looking into video cameras when I worked in the school's audio >visual room as my prefect duty in the sixth form (a really cushy number, >getting to play with someone else's expensive kit, instead of having to
break up playground fights or keep order in the dinner queue). And there
were two categories: single tube with a striped filter and three tube with a >prism. The latter were bigger and more expensive: they produced better >pictures but were more prone to the tubes getting out of registration.
Even nowadays, many cheaper cameras, both consumer and professional, have a >single CCD sensor and a stripe filter - and others are sold as "3 CCD".
I believe some professional tube cameras had *four* tubes: three for the >colours and a separate one for the luminance rather than deriving it from >(approx) 30:60:10 percent proportions of RGB.
As for the pro cameras with the turret lenses. I did often wonder why they >did it that way, as it made an already heavy camera even heavier.
it uses a tiny 4 Gigabyte hard drive, which fits in a Compact Flash
socket. At the time, the available CF cards were less than a gigabyte,
very expensive per megabyte, and 4 GB in the same space was spectacular.
But yellow, seems to suggest that it was two colours that were running
into trouble, unless they used some type of complimentary colour system of unknown sort.
I do wish these days when recording dialogue they would try to at least make sure we can hear the actors over the background.
So are there any cheap tie clip mikes that can be used wirelessly by incompetent people who keep on moving. grin!
On Sat, 14 May 2022 10:06:36 +0100, "Brian Gaff \(Sofa\)" <briang1@blueyonder.co.uk> wrote:
As for the pro cameras with the turret lenses. I did often wonder why they >>did it that way, as it made an already heavy camera even heavier.
Prime lenses have less glassware than zooms, therefore not so much
light loss.
The practice of smoothly varying the focal length during a shot seems
to be one of those things that nobody needed to do, until they could.
Classic movies are almost completely devoid of it.
On Fri, 13 May 2022 22:19:04 +0100, "NY" <me@privacy.invalid> wrote:
I believe some professional tube cameras had *four* tubes: three for the >>colours and a separate one for the luminance rather than deriving it from >>(approx) 30:60:10 percent proportions of RGB.
The colorimetry is wrong if you use the luminance tube to produce the
entire luminance signal, because the three colour signals would be effectively already mixed before gamma correction, which doesn't match
what is done to the red green and blue signals. Therefore, the
luminance tube is only used to produce the fine detail, which is what
would suffer first through misregistration if it were derived by
adding the outputs of three tubes.
Three tube cameras would usually derive the fine detail from the green signal, which is very similar. Manufacturers soon realised this gave
results that were almost indistinguishable, and it was cheaper.
On Sat, 14 May 2022 10:06:36 +0100, "Brian Gaff \(Sofa\)" <briang1@blueyonder.co.uk> wrote:
As for the pro cameras with the turret lenses. I did often wonder why they >>did it that way, as it made an already heavy camera even heavier.
Prime lenses have less glassware than zooms, therefore not so much
light loss.
On 14/05/2022 10:12, Brian Gaff (Sofa) wrote:
I do wish these days when recording dialogue they would try to at
least make sure we can hear the actors over the background.
So are there any cheap tie clip mikes that can be used wirelessly by incompetent people who keep on moving. grin!
Biggest problem that I notice is muffled sound because the microphone is under a coat, fleece etc.
"John Williamson" <johnwilliamson@btinternet.com> wrote in message news:je91a2FmhjjU1@mid.individual.net...
it uses a tiny 4 Gigabyte hard drive, which fits in a Compact Flash
socket. At the time, the available CF cards were less than a gigabyte,
very expensive per megabyte, and 4 GB in the same space was spectacular.
I've seen photos of those CF spinning-HDD cards. It is one hell of an achievement to make an HDD which is less the 2 mm thick. Diameter of
about 30 mm is an achievement too, but less gobsmacking than the thickness.
I believe that the light-versus-signal response for a tube camera had a >"knee" at the upper end of the response curve (which should ideally be
a straight diagonal line or a simple curve) and this meant that tube
cameras tended to fail a little more gracefully because over-bright
areas didn't suddenly hit the maximum signal level but gave a little
bit of headroom to show at least *some* detail in the highlight. I
could be talking a load of bollocks with that ;-) I wonder if the same >principle applies to film: you don't tend to see bright highlights that
have a colour cast as opposed to just becoming peak white.
"J. P. Gilliver (John)" <G6JPG@255soft.uk> wrote in message >news:NubDMoJ9mrfiFw5n@a.a...[]
[]If it wasn't a CCD, it was probably three (for amateur use) tubes;
colour haloing in bright conditions was, I think, caused by one of
the tubes hitting its limit (the video equivalent of clipping in
audio - saturation?) before the others did.
(I don't _think_ any tube cameras used many tiny multicoloured
filters - or stripes - to get colour our of a single tube; I think
the syncing - plus, memory aspects in those days - would have been
too horrendous. But I may be wrong.)
I remember looking into video cameras when I worked in the school's
queue). And there were two categories: single tube with a striped
filter and three tube with a prism. The latter were bigger and more
expensive: they produced better pictures but were more prone to the
tubes getting out of registration.
Even nowadays, many cheaper cameras, both consumer and professional,
have a single CCD sensor and a stripe filter - and others are sold as
"3 CCD".
I believe some professional tube cameras had *four* tubes: three for
the colours and a separate one for the luminance rather than deriving
it from (approx) 30:60:10 percent proportions of RGB.
Tube cameras were notorious for lag and smear: you often saw it if a
bright candle flame was seen in a studio-based drama: as the flame
flickered there was a coloured after-image which lasted several
seconds. And programmes like Top of the Pops, which often had low
camera angles that happened to "see" the studio lights, often led to a >streaky after-image as the camera panned across the light.
For *really* bad overexposure artefacts, you have to go back further
into history to the days of image orthicons. They produced a lovely
crisp, clean (not muddy, like a vidicon) image, but they went seriously
loopy if part of the image was overexposed. Around a very bright object
you got a big black halo which made the correctly-exposed part of the
image nearby darker in that area than it was elsewhere. I believe a
very dark area against a lighter grey produced the opposite effect: a
whiter halo around black patch which extended into the mid-grey part of
the subject. I'm sure someone will be along to explain the[]
technicalities of localised electron depletion on the camera's sensor
better than I could ;-)
I imagine when zoom lenses first became available it was a real novelty
"Roderick Stewart" <rjfs@escapetime.myzen.co.uk> wrote in message >news:4sru7hhotvh1euhh1utpoe8pq5b7mkeidq@4ax.com...
On Fri, 13 May 2022 22:19:04 +0100, "NY" <me@privacy.invalid> wrote:
I believe some professional tube cameras had *four* tubes: three for the >>>colours and a separate one for the luminance rather than deriving it from >>>(approx) 30:60:10 percent proportions of RGB.
The colorimetry is wrong if you use the luminance tube to produce the
entire luminance signal, because the three colour signals would be
effectively already mixed before gamma correction, which doesn't match
what is done to the red green and blue signals. Therefore, the
luminance tube is only used to produce the fine detail, which is what
would suffer first through misregistration if it were derived by
adding the outputs of three tubes.
Three tube cameras would usually derive the fine detail from the green
signal, which is very similar. Manufacturers soon realised this gave
results that were almost indistinguishable, and it was cheaper.
Isn't there a mathematical transformation that can be applied (especially >nowadays where everything is digital) which un-gammas a copy of the R G and >B, mixes them and then re-gammas the result? I imagine trying to achieve
this in electronic hardware is considerably harder than doing it in software >;-)
I believe some professional tube cameras had *four* tubes: three for the colours and a separate one for the luminance rather than deriving it from (approx) 30:60:10 percent proportions of RGB.
On 14/05/2022 10:12, Brian Gaff (Sofa) wrote:
I do wish these days when recording dialogue they would try to at least
make sure we can hear the actors over the background.
So are there any cheap tie clip mikes that can be used wirelessly by
incompetent people who keep on moving. grin!
Biggest problem that I notice is muffled sound because the microphone is under a coat, fleece etc.
In article <t5o1q6$7r2$1@dont-email.me>, MB <MB@nospam.net> wrote:
On 14/05/2022 10:12, Brian Gaff (Sofa) wrote:
I do wish these days when recording dialogue they would try to at
least make sure we can hear the actors over the background.
So are there any cheap tie clip mikes that can be used wirelessly by
incompetent people who keep on moving. grin!
Biggest problem that I notice is muffled sound because the microphone is
under a coat, fleece etc.
far worse is the speaker turing their head away from straight ahead.
That's why I prefer head set mics.
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
I saw a very long focal-length zoom (not sure what its wide-angle setting >was, but it was designed for greater magnification than normal at the >telephoto end) and it was a big bugger - it looked to be about 6 feet long, >so, given the large diameter lenses in it, it would have been very heavy. I >imagine the camera would have had to be mounted further back than normal so >it didn't continually try to tilt forwards.
Yes but on TV, you cannot have everyone using headsets can you. I remember >having what was described as a gun mike. That was fine as long as the person >who was aiming it was paying attention and both parties were near each
other, but on some occasions, yougot echo from a wall behind the people etc.
Brian
On Fri, 13 May 2022 15:41:49 +0100, "NY" <me@privacy.invalid> wrote:
I saw a very long focal-length zoom (not sure what its wide-angle setting >>was, but it was designed for greater magnification than normal at the >>telephoto end) and it was a big bugger - it looked to be about 6 feet
long,
so, given the large diameter lenses in it, it would have been very heavy.
I
imagine the camera would have had to be mounted further back than normal
so
it didn't continually try to tilt forwards.
Sounds like something used for space exploration or orbital spy
satellites!
On Sun, 15 May 2022 13:43:05 +0100, "Brian Gaff \(Sofa\)" <briang1@blueyonder.co.uk> wrote:
Yes but on TV, you cannot have everyone using headsets can you. I remember >>having what was described as a gun mike. That was fine as long as the >>person
who was aiming it was paying attention and both parties were near each >>other, but on some occasions, yougot echo from a wall behind the people >>etc.
Brian
A few more years and microphone implants will be used. I think the top
lip would be the best position (except for boxers).
I have embarrassing memories of trying to take photos of puffins as they
flew over a headland and into shot. My wife had her camera's auto-focus set to use a fairly small circle, and she was able to keep the puffins in that area as the bird flew on an unpredictable path, so the focus continuously adjusted as the bird approached. I found couldn't do this consistently and had to go for a larger focussing zone which was find until a tree branch or
a bit of ground got into frame and the camera would focus on*that* if it
was closer, rather than on the bird. Ideally I'd have had the camera on a tripod with loose pan-tilt so I could move it in any direction but wasn't having to bear the weight of a heavy DSLR and heavy lens. Something that moves more predictably like a racing car on a track, is much easier to
follow and keep accurately in frame: I've taken a number of pictures of passing cars with a slow shutter speed to blur the background, and with the car pin-sharp so I was following it exactly.
On 15/05/2022 21:38, NY wrote:
I have embarrassing memories of trying to take photos of puffins as they
flew over a headland and into shot. My wife had her camera's auto-focus
set
to use a fairly small circle, and she was able to keep the puffins in
that
area as the bird flew on an unpredictable path, so the focus continuously
adjusted as the bird approached. I found couldn't do this consistently
and
had to go for a larger focussing zone which was find until a tree branch
or
a bit of ground got into frame and the camera would focus on*that* if it
was closer, rather than on the bird. Ideally I'd have had the camera on a
tripod with loose pan-tilt so I could move it in any direction but wasn't
having to bear the weight of a heavy DSLR and heavy lens. Something that
moves more predictably like a racing car on a track, is much easier to
follow and keep accurately in frame: I've taken a number of pictures of
passing cars with a slow shutter speed to blur the background, and with
the
car pin-sharp so I was following it exactly.
I usually find auto-focus makes following a moving object more difficult because it is quite likely to focus elsewhere brifly.
If it is a bright sunny day then I rely on depth of field on manual focus.
Yes I did try that: stop down as far as I dare without prejudicing shutter speed (puffins' wings move very quickly) and hope that the birds remain reasonably in focus as they get closer.
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