Не будь раскадровки, режиссёр бы не выбрал крупный план.

It looks like the imperative of быть, but in this sentence it is part of a fixed conditional expression.

Не будь раскадровки means something like:

• if there were no storyboard
• were it not for the storyboard
• had there been no storyboard

So this is not really telling someone don’t be. It is a set phrase used in hypothetical, often slightly bookish or formal, statements.

A fuller, less compact version would be:

Если бы не было раскадровки, режиссёр бы не выбрал крупный план.

Because the construction не будь + noun in the genitive requires the genitive.

So:

• не будь раскадровки
• не будь помощи
• не будь дождя

This matches the idea of absence / non-existence, which often triggers the genitive in Russian.

You can think of it as related in meaning to не было раскадровки, where раскадровки is also genitive.

Russian often allows a shorter, more compressed structure in formal or literary language.

Instead of saying:

Если бы не было раскадровки...

the sentence uses the shorter:

Не будь раскадровки...

So the first clause is essentially an abbreviated conditional clause. The idea of there being / existing is understood, even though it is not spelled out with было.

Бы marks the conditional mood in Russian.

So:

• выбрал = chose
• бы выбрал = would choose / would have chosen

In this sentence, the speaker is talking about an unreal, hypothetical situation:

If there had been no storyboard, the director would not have chosen a close-up.

That is why бы is needed.

In Russian, in an если бы sentence, бы can appear in both parts or only in one part, depending on the structure and style.

Here, the first clause uses the special expression не будь раскадровки, so the conditional meaning is already built into that phrase. Because of that, бы appears in the main clause:

Не будь раскадровки, режиссёр бы не выбрал крупный план.

A more expanded version would be:

Если бы не было раскадровки, режиссёр бы не выбрал крупный план.

So the sentence is completely normal as written.

Выбрал is the perfective past form of выбрать, and it fits because the sentence refers to a single completed choice.

The director is imagined as making one decision: whether to choose the close-up or not.

• выбрал = chose / would have chosen
• выбирал = was choosing / used to choose / chose repeatedly, depending on context

Since this is about one finished decision in a hypothetical situation, выбрал is the natural choice.

It is the direct object of выбрал, so it is in the accusative case.

However, крупный план is a masculine inanimate noun phrase, and for masculine inanimate nouns, the accusative looks the same as the nominative:

• nominative: крупный план
• accusative: крупный план

So even though it is accusative here, its form does not change.

It is understandable and correct, but it sounds more compressed, written, or somewhat literary than the most neutral everyday version.

In everyday speech, many people would more naturally say:

Если бы не было раскадровки, режиссёр бы не выбрал крупный план.

So:

• не будь раскадровки = more concise, somewhat elevated
• если бы не было раскадровки = more neutral and transparent

Yes. Both are good ways to capture the meaning.

Depending on context, you could translate it as:

• If it weren’t for the storyboard, the director would not have chosen a close-up.
• Had there been no storyboard, the director would not have chosen a close-up.
• Were it not for the storyboard, the director would not have chosen a close-up.

The Russian structure is flexible enough to match any of those English versions.

Yes, but the original order is very natural because it puts the condition first and the result second:

Не будь раскадровки, режиссёр бы не выбрал крупный план.

You could also reorder it for stylistic reasons, for example:

Режиссёр бы не выбрал крупный план, не будь раскадровки.

That sounds a bit more literary, but it is still correct. The original version is probably the clearest for a learner.

In Russian, this kind of conditional with past-tense forms plus бы can express an unreal present or an unreal past, depending on context.

So this sentence could mean either:

• If there were no storyboard, the director would not choose a close-up
  or
• If there had been no storyboard, the director would not have chosen a close-up

Without extra context, Russian does not always force that distinction as clearly as English does. The broader situation tells you which interpretation is intended.