How at old tv sets the image apears in only 5 seconds?

[Telecolor 3007]

Well, I don't know how they are doin' it, but the guys how are making the movies make at the old tv sets the image to appear in less than 5 seconds.
I saw a movie (Girl, intrerrupted), in whic they shown an '60's color set with recatngural picture tube (i don't know if the set was all-tube, hybrid or soli-state). The image apeard aftre 3 seconds. I wonder how could that happend?
On my 1984 Teleocolor 3007 the image apears after 4-5 seconds. Those guys know nothing about old tv and old radios.