Объектив и фокус кинокамеры проверены.

Because the subject is actually two things joined by и:

• объектив = the lens / objective
• фокус кинокамеры = the focus of the movie camera

Together they make a plural subject, so the predicate must also be plural.

That is why Russian uses:

• singular masculine: проверен
• plural: проверены

So Объектив и фокус кинокамеры проверены literally means The lens and the camera’s focus are / have been checked.

In Russian, the verb to be is usually omitted in the present tense.

So where English says:

• The lens and focus are checked
• The lens and focus have been checked

Russian can simply say:

• Объектив и фокус кинокамеры проверены

The idea of are / have been is understood from the form проверены and from context.

Проверены is the short-form passive participle of проверить.

That sounds technical, but the important idea is simple: it means something like checked, verified, or inspected, with the sense that someone has done that action to the objects.

Compare:

• проверить = to check
• проверен = checked, for one masculine item
• проверена = checked, for one feminine item
• проверено = checked, for one neuter item
• проверены = checked, for plural items

Here it is plural because there are two things being talked about.

No, here кинокамеры is most likely genitive singular, not plural.

The base word is:

• кинокамера = movie camera / film camera

After another noun, Russian often uses the genitive to show a relationship like of the camera.

So:

• фокус кинокамеры = the focus of the movie camera

Even though кинокамеры can also look like nominative plural in other contexts, here the meaning and structure show that it is genitive singular.

Because the phrase is structured as:

• Объектив
• и фокус кинокамеры

So grammatically, кинокамеры directly modifies фокус.

This means the sentence most literally reads:

• The lens and the movie camera’s focus have been checked

It does not automatically mean:

• the movie camera’s lens and focus

Even though in real-world context that may be what the speaker intends, the grammar most directly links кинокамеры to фокус.

If someone wanted to make it clearer that both belong to the camera, they might rephrase the sentence.

They are in the nominative case, because they are the subject of the sentence.

You can think of them as the things that are checked.

So the structure is:

• Объектив — nominative singular
• фокус — nominative singular
• joined by и = together a plural subject
• проверены — plural to match that subject

Yes, it is a complete sentence.

In Russian, short-form passive participles like проверены can function as the main predicate of a sentence.

So this is a normal complete statement, not a fragment.

A very literal breakdown would be:

• Объектив и фокус кинокамеры = the lens and the camera’s focus
• проверены = checked / have been checked

Yes, Russian word order is fairly flexible.

This sentence could be rearranged for emphasis, for example:

• Объектив и фокус кинокамеры проверены.
• Проверены объектив и фокус кинокамеры.

Both are grammatical.

The original order is neutral and straightforward. Putting проверены first can sound a bit more like emphasizing the result: Checked are the lens and the camera’s focus.

Объектив is the standard Russian word for a camera lens or objective lens.

It is the normal technical word you would expect in photography or cinematography.

A learner might also know:

• линза = lens in a more general sense, like a physical lens or eyeglass lens

But for a camera lens, объектив is the usual word.

Yes, it matters for agreement.

• объектив is masculine
• фокус is masculine
• кинокамера is feminine

If each noun appeared alone with проверен / проверена, the form would change:

• Объектив проверен.
• Кинокамера проверена.
• Фокус проверен.

But because объектив and фокус are combined with и, the result is plural:

• Объектив и фокус проверены.

It can mean any of those depending on context.

The basic idea is that they were examined to make sure everything is correct or functioning properly.

Possible English translations include:

• checked
• verified
• inspected

In a technical or equipment-related context, checked is often the most natural translation.