I'm curios, why early studio cameras used a turret of lens in stad of one lens unit?

Zoom didn’t really exist. So to change from wide to close in, you had to change lenses.

Zoomar was an early zoom lens out here. They were made not far from where I grew up.

Early zoom lenses did not have a wide range by today's standards. This one appears to be marked 55mm to 160mm
https://www.worthpoint.com/worthopedia/rca-tk-41-zoomar-super-studio-lens-138395817

Those were the days of directors calling to 'truck in' or 'dolly in'. Need a closer shot? Move there, physically. Or, cut away, change lens, cut back.

Those were the days of directors calling to 'truck in' or 'dolly in'. Need a closer shot? Move there, physically. Or, cut away, change lens, cut back.

In early programs, there were also times when a dolly tire had a flat spot, and you would see the camera nod periodically if it was dollying on air.

Here, following time 00:30, you can see a dolly shot with a bit of a wobble.
https://www.youtube.com/watch?v=g09PFJOz1Ug&list=RDkM66bBjPW7M&index=12

The Bell Telephone Hour used dolly shots extensively.

Probably a union thing so the dolly operator would always have a job.

Then, when zoom lenses became available, the "truckin' zoom" was quickly discovered: Dolly in at the same rate you're zooming out (or the inverse) to give a radically different depth of field/background look while retaining the same image size of the primary subject. Can add quite a dramatic effect to an otherwise static scene. Requires excellent coordination of personnel for manual execution, or a trivial bit of code if you're in a motion control/automated camera scenario.

As Chip Chester says, zooming and tracking give very different effects. Zooming changes the perspective of the scene, tracking does not. Long focal length flattens perspective, wide angle exaggerates it, leading to the infamous "donkey shot". Portrait photography was often done with a somewhat long lens to avoid exaggerating long noses.

As others have said, zoom lenses simply weren't available in the early days. The very earliest camers didn't even have turrets, just a single fixed focal length lens.

Yes, true. At 1936 Olympics the Germans had a single lens camera.
But wait a minute, the turret wasn't operated by the cameraman?

...
But wait a minute, the turret wasn't operated by the cameraman?

The turret was operated by the cameraman. The zoom was also operated by the cameraman in early TV and generally in live TV. In live TV, use of zoom for effect was/is uncommon [Edit: except to replace the sort of dollying you see in Telephone Hour tapes]. It is used mainly for framing.

But for film, or later, pre-made video, the cinematic special effect of zooming and dollying simultaneously would have to be done by two people, as coordination would be too difficult for one person. Also, the camera tilt and pan would very likely be locked down so that it couldn't be disturbed. [Edit: and it would be shot several times to try to get it right.]

As stated above, a guaranteed smooth effect is obtained by computer motion-control of camera position and zoom.

https://www.youtube.com/watch?v=g09PFJOz1Ug&list=RDkM66bBjPW7M&index=12

The Bell Telephone Hour used dolly shots extensively.

I'm guessing The Doors never appeared on The Bell Telephone Hour?

The Bell clip looks to only have two cameras on it. Most of it was a Chapman crane floating along as part of the sweeping choreography. Directors prerogative. Cranes were so much better for any kind of moving shot as the camera was so far removed from the wheels but still could wobble at the end of the arm. Momentum in action. There is only one ground shot early on. Bell was shot at the NBC Brooklyn studios which had the space for all of this.

Bobby Ellerbee has a nice page on Brooklyn here;

http://eyesofageneration.com/nice-shot-nbc-brooklyn-studiosjodie-peeler-sent-me-this-recently-and-as-i-stud/

Here is another Bell clip that has two cranes and two pedestal cameras, one with a zoom for sure and the other with just a turret.

https://www.youtube.com/watch?v=JZ2diDZf5nM

Thanks for posting that BTH clip. I see a zoom at 3:11, all the rest seem to be camera moves (?).

Wayne, I am deducing this from may years of directing and trying to figure out what the director (Clark Jones) had in the studio. The opening shot of Florence Henderson is pedestal/turret and that camera vacated to in-between the audience risers for the head-on shot of the artist. The zoom camera was down stage next to the down stage crane and not used much, nor would it have to cross the crane camera cable to shoot Florence. The other crane was backstage looking down at the orchestra and the reverse shot of the piano. All of this is classic Clark Jones style. One of the most famous entertainment directors of the day.

From personal experience behind a TK-43, I can say that a heavy camera up high on a pedestal is just not good for dolly/truck shots. And you "dolly in/out". You "truck L/R". Any bump by the wheels just amplifies up to the high center of gravity camera, just like the end of a fishing pole.

And an added note. Zoom lenses have a long history in film but were not used much in the studio. They were just a quick way to change lens lengths but not for screen. Paramount used these heavily.

Thanks, Dave. Always good to hear the analysis from experienced eyes.

Telecolor, you asked about control of the turret.

The outside cameras used at the World's Fair in 1939 only had no turret and only one lens, but they had remote control of the focus. The reason was that they didn't have either an electronic viewfinder or a twin-lens optical viewfinder, only a wire sighting frame. So, the video engineer/shader had to adjust focus remotely.

http://www.bretl.com/tvarticles/images/SarnoffatRCApavilion1939.jpg

Some much later closed circuit cameras had remote controlled turrets.
An extreme example is the RCA TK-45 color Vidicon camera (the 1960 version, not the 1973 studio Plumbicon camera that used the same number). It had remote turret and focus, and was used at the U.S. Walter Reed medical center (at least three), Strategic Air Command weather center, University of Michigan, and the Museum of Science and Industry in Chicago.

https://www.oldradio.com/archives/hardware/TV/RCA-TV.htm

I have not seen any record of how many were sold, but it must have been very few, as the camera required extremely high light levels and was undoubtedly expensive.

Of course, these days, small high-definition pan-tilt-zoom (PTZ) webcams are easily available.

ISTR reading that the zoomar lenses were more common in sports telecasts.

Zooms were a sports staple when available. Very hard to follow a home run with a turret. A studio drama did not need them as it was usually a small box studio and a turret did the work. Just make sure you did the turret swing quietly (squeeze/turn/release slowly) so the audience did not hear the clank as the new lens fell in to place. It was useful for programs like Today with a zoom in to Dave Garroway to save a closeup camera for another shot. Same for the early Tonight Show.

About half way down this page:
2 TK-41s wiht the longer focal length Zoomar version, for baseball:
https://chicagobaseballmuseum.org/chicago-baseball-history-news/chicago-baseball-history-feature/daily-wgn-cubs-sox-baseball-telecasts-1948-spurred-tvs-growth/