Ovdje je nadzorna kamera.

Yes. Ovdje means here and is a very common, neutral way to say it.

A few useful points:

• ovdje = here
• It is an adverb, so it does not change for gender, number, or case.
• In everyday speech, many speakers also use tu, which can also mean here or there, depending on context.

So:

• Ovdje je nadzorna kamera. = There is a surveillance camera here.
• Tu je nadzorna kamera. = very similar, often more conversational.

Je is the 3rd person singular present of biti (to be): is.

In Croatian, short unstressed forms like je are clitics, and they often appear in the second position of the sentence or clause.

That is why you get:

• Ovdje je nadzorna kamera.

rather than a more English-like order such as:

• Ovdje nadzorna kamera je. — not natural

So the structure is:

• ovdje = here
• je = is
• nadzorna kamera = surveillance camera

Because nadzorna is an adjective that must agree with kamera in:

• gender
• number
• case

Here, kamera is:

• feminine
• singular
• nominative

So the adjective also has to be:

• feminine
• singular
• nominative

That gives:

• masculine: nadzoran
• feminine: nadzorna
• neuter: nadzorno

Since kamera is feminine, the correct form is nadzorna kamera.

It is in the nominative singular.

That is because nadzorna kamera is the noun phrase being identified or presented in the sentence:

• Ovdje je nadzorna kamera. = There is a surveillance camera here.

The basic form of the noun is:

• kamera = camera

and here it stays in that basic nominative form.

Croatian has no articles, so there is no direct equivalent of English a, an, or the.

That means:

• kamera can mean a camera or the camera
• context tells you which meaning is intended

So nadzorna kamera can mean:

• a surveillance camera
• the surveillance camera

depending on the situation.

In this sentence, English usually translates it naturally as a surveillance camera.

Yes, you can, but the emphasis changes.

• Ovdje je nadzorna kamera.
  This sounds like There is a surveillance camera here. It presents the location first.

• Nadzorna kamera je ovdje.
  This sounds more like The surveillance camera is here. It focuses more on the camera itself.

So both are grammatical, but they are not identical in nuance.

No, they mean different things.

• Ovdje je nadzorna kamera. = There is a surveillance camera here.
• Ovo je nadzorna kamera. = This is a surveillance camera.

The key difference:

• ovdje = here → location
• ovo = this → pointing to or identifying something

So if you are talking about what is present in a place, use ovdje. If you are identifying an object, use ovo.

Yes, very often.

• Ovdje je nadzorna kamera.
• Tu je nadzorna kamera.

Both can mean There is a surveillance camera here.

A rough difference:

• ovdje can feel a bit more explicit or formal for here
• tu is extremely common in everyday speech

In many situations, either one works.

A simple approximate pronunciation for an English speaker is:

OV-dye ye NAD-zor-na KAH-me-ra

A few details:

• ovdje: the dj sound is similar to the gy sound in some pronunciations of duke, though not exactly the same
• je sounds roughly like ye
• kamera is pronounced clearly in syllables: ka-me-ra

Croatian spelling is fairly phonetic, so once you know the sound rules, pronunciation is usually predictable.

It is natural and correct.

A Croatian speaker could definitely say:

• Ovdje je nadzorna kamera.

especially when warning someone, pointing something out, or explaining a location.

For example:

• in a shop
• at an entrance
• in a hallway
• in a building with security monitoring

It is a normal sentence, not an unnatural word-for-word translation from English.

Yes, it is a standard and very common expression for surveillance camera or security camera.

Literally:

• nadzorna relates to supervision / monitoring
• kamera = camera

So together:

• nadzorna kamera = surveillance camera

You may also hear related expressions in different contexts, but nadzorna kamera is the basic standard term.