Mióta tudok fókuszálni, ritkán van bemozdulás.

Here mióta introduces a time clause and means since.

So Mióta tudok fókuszálni means roughly since I’ve been able to focus or ever since I learned to focus.

A useful thing to know is that mióta can also appear in questions, where it means since when? or for how long?
For example:

• Mióta laksz itt? = How long have you lived here?

But in your sentence it is not a question word; it is a conjunction introducing the first clause.

Both are possible.

• amióta is the fuller form and often sounds a bit more explicit or standard in careful language
• mióta is also very common and natural

So:

• Amióta tudok fókuszálni, ritkán van bemozdulás.
• Mióta tudok fókuszálni, ritkán van bemozdulás.

Both work. A learner will often meet amióta in textbooks, but real speech very often has mióta.

This is a very common Hungarian-English difference.

Hungarian often uses the present tense for something that started in the past and still continues now. English frequently uses the present perfect in the same situation.

So:

• Mióta tudok fókuszálni...
  literally looks like Since I can focus...
• but in natural English it often corresponds to
  Since I’ve been able to focus... or Ever since I learned to focus...

This is the same pattern as:

• Két éve itt lakom. = I have been living here for two years.

So the Hungarian present tense here is completely normal.

tudok fókuszálni is tud + infinitive.

That pattern means:

• can do something
• know how to do something
• be able to do something

So tudok fókuszálni means I can focus or I’m able to focus.

The important structure is:

• tudok = I can / I know how to
• fókuszálni = to focus

Hungarian often uses tud + infinitive where English uses can.

Because Hungarian verbs already show the subject.

tudok ends in -ok, which tells you the subject is I. So én is usually unnecessary.

• (Én) tudok fókuszálni. = I can focus.

Hungarian normally leaves out personal pronouns unless they are needed for emphasis or contrast.

For example:

• Én tudok fókuszálni, ő nem. = I can focus, he/she can’t.

In your sentence, there is no special emphasis, so leaving out én is normal.

It depends on context.

fókuszálni can mean:

• to focus in a technical sense, especially with cameras, lenses, optics
• to focus / concentrate in a more general sense

Because the sentence also has bemozdulás, which is often used in imaging or photography contexts, fókuszálni here likely has a camera- or image-related sense.

A few related verbs:

• fókuszálni = to focus
• összpontosítani = to concentrate, to focus mentally
• élességet állítani = to adjust focus, set sharpness

So fókuszálni is a natural choice, especially in technical or photo-related language.

bemozdulás usually refers to a slight unwanted movement, and in photo/video contexts it often means:

• motion blur
• camera shake
• blur caused by movement

So ritkán van bemozdulás means that this kind of blur or shake happens only rarely.

This noun comes from bemozdul, which means something like to move slightly or to shift. In imaging contexts, that slight movement causes the blur.

Because Hungarian very often uses van + noun to express that something exists or occurs.

So:

• van bemozdulás = there is motion blur / motion blur occurs
• ritkán van bemozdulás = there is rarely motion blur

This is a very common Hungarian pattern. It does not always match English word-for-word, but it is natural Hungarian.

Compare:

• Van probléma. = There is a problem.
• Néha van késés. = Sometimes there is a delay.

So van here is functioning like there is.

Because the sentence is talking about the phenomenon in a general, indefinite way.

• ritkán van bemozdulás = there is rarely any motion blur / motion blur rarely occurs

A bare noun is common in this kind of existential statement.

If you added a, it would sound like you mean a specific, already known instance:

• van a bemozdulás would suggest the motion blur is there, which does not fit this sentence well

So the article is omitted because bemozdulás is being used generally, not as a specific identified thing.

That is the neutral, natural position for the adverb here.

• ritkán van bemozdulás = there is rarely motion blur

Hungarian word order is flexible, but the position of words often changes emphasis.

This version is neutral:

• Ritkán van bemozdulás.

If you move things around, the emphasis changes. For example:

• Bemozdulás ritkán van.
  This sounds more contrastive, as if you are especially emphasizing motion blur.

So for a plain statement, ritkán van bemozdulás is a very normal order.

Because the sentence begins with a subordinate clause:

• Mióta tudok fókuszálni = subordinate time clause
• ritkán van bemozdulás = main clause

Hungarian usually separates such clauses with a comma.

So the punctuation is standard:

• Mióta tudok fókuszálni, ritkán van bemozdulás.

This is similar to English punctuation in sentences like:

• Since I’ve been able to focus, motion blur is rare.

It describes a general pattern.

Two things point to that:

• mióta sets up a time period starting in the past and continuing
• ritkán means rarely, which describes repeated frequency, not a one-time event

So the idea is not there was one case of blur, but rather from that point on, blur has been rare.

That is why the sentence feels like a summary of experience rather than a report about one single moment.