I managed to obtain a second-hand copy of Cameras on Carolyn at some considerable expense. While I enjoyed it, I’d recommend reading it for free via a deposit library rather than investing in it yourself (unless you can find it for a couple of quid in a second-hand shop).
The story picks up from “Stage Under the Cedars” with the heroine Carolyn now sharing a flat in London with her drama school friend Phoebe, both trying to forge their way as actresses. The first half is very enjoyable and feels satisfyingly realistic. Apparently Irene Byers interviewed many young actors and actresses for this novel, which paid off. Carolyn remains consistently sulky and rather useless (there is no way this girl would ever make it as an actress in the real world) but the character consistency is nice.
The second half gets a bit “Byers” for want of a better description. Rather too twee, too many coincidences and a suffocatingly small cast of players. The filming “plot” at the party is beyond implausible and cringeworthy. The romance also feels rather crowbarred in and rushed. If this had been split into two books and expanded, perhaps with a three year gap in between, it would have been far better.
The villainess’s plotting is rather implausible: she has already “made it”, thus why she would feel the need to continually sabotage the career of someone markedly less talented and less attractive is never really explained. The prima donna doesn’t put glass in the understudy’s slipper, so to speak, it’s the other way around.
There’s a gloriously dated illustration of “young people” with sideburns etc socialising at a party in my edition (this almost made the price worthwhile). I have uploaded a copy here: