Не будь съёмочной группы, короткометражку бы не закончили.

In this sentence, Не будь + noun means if it weren’t for... / had it not been for...

So:

• Не будь съёмочной группы = If it weren’t for the film crew
• Whole sentence: If it weren’t for the film crew, they wouldn’t have finished the short film.

This is a compact, somewhat literary way of expressing a condition.

Formally, будь is the imperative form of быть (to be), so it looks like don’t be.

But in this sentence, that is not how it functions.
Не будь + Genitive is a fixed conditional expression meaning:

• were it not for...
• if there were no...
• had it not been for...

So here you should understand it as a set construction, not as a real command.

Compare:

• Не будь грубым. = Don’t be rude. ← real imperative
• Не будь съёмочной группы, ... = If it weren’t for the film crew, ... ← fixed conditional pattern

Because this construction normally uses the genitive after не будь.

So:

• съёмочная группа = nominative
• съёмочной группы = genitive

This is connected to the idea of non-existence / absence: literally, the phrase is close in meaning to if there were no film crew. Russian often uses the genitive in negated existence-type expressions.

A fuller version would be:

• Если бы не было съёмочной группы...

And after не было, the genitive is also expected.

Because не будь already carries the conditional idea in this shortened structure.

So Russian does not need to say:

• Не будь ... бы ...

Instead it says:

• Не будь съёмочной группы, короткометражку бы не закончили.

The бы in the main clause marks the result as hypothetical / unreal:

• не закончили = didn’t finish
• бы не закончили = wouldn’t have finished

A fuller, less condensed version would be:

• Если бы не было съёмочной группы, короткометражку бы не закончили.

There is no explicit subject, and that is very normal in Russian.

Закончили is 3rd person plural past, but here it means something like:

• they wouldn’t have finished
• the people involved wouldn’t have finished
• or in more natural English, the short film wouldn’t have been finished

Russian often uses 3rd person plural with no subject when the doer is indefinite, obvious from context, or unimportant.

So this is not necessarily talking about a specific they in the English sense. It is more like an unspecified human subject.

Because it is the direct object of закончили.

• короткометражка = nominative
• короткометражку = accusative

The verb закончить means to finish something, so it takes a direct object:

• закончить фильм
• закончить работу
• закончить короткометражку

Also, короткометражка is a common colloquial word for short film / short movie.

Закончили is the past tense plural of the perfective verb закончить.

That matters because:

• perfective focuses on the completed result
• with бы, it gives a counterfactual meaning: wouldn’t have finished

So:

• не закончили = didn’t finish
• бы не закончили = wouldn’t have finished

Using the perfective is natural here because the sentence is about whether the short film reached completion.

Yes, it is correct and natural, but the construction не будь + Genitive sounds a bit more bookish, compact, or literary than the most everyday version.

More neutral alternatives would be:

• Если бы не съёмочная группа, короткометражку бы не закончили.
• Если бы не было съёмочной группы, короткометражку бы не закончили.
• Без съёмочной группы короткометражку бы не закончили.

So the original sentence is perfectly good Russian, but it is slightly more stylistically elevated.

Because the sentence has two parts:

1. the condition: Не будь съёмочной группы
2. the result: короткометражку бы не закончили

The comma separates the conditional part from the main clause, just as English often separates an initial if-clause from the rest of the sentence.

Yes. Russian word order is flexible, and you can move parts around for emphasis.

For example, you could also say:

• Короткометражку бы не закончили, не будь съёмочной группы.

That means essentially the same thing.

The original order puts the condition first, which is very natural here. It foregrounds the idea that the film crew was the crucial factor.

Yes, absolutely. That is probably the most useful everyday equivalent for a learner.

For example:

• Если бы не съёмочная группа, короткометражку бы не закончили.

This means almost the same thing as the original sentence.

A rough comparison:

• Не будь съёмочной группы... = more condensed, more literary
• Если бы не съёмочная группа... = more neutral and common in speech

So if you understand the original but are not ready to use it actively, если бы не is a very safe alternative.