Ο φωτογράφος θέλει να κάνουμε τη φωτογράφιση το πρωί, γιατί τότε το φως είναι πιο απαλό.

Modern Greek normally uses να + a finite verb where English often uses an infinitive.

So:

• θέλει να κάνουμε = he wants us to do / he wants us to have
• literally, it is something like he wants that we do

English says wants to do or wants us to do, but Greek usually uses να instead of an infinitive.

Yes. Κάνουμε is the 1st person plural form: we do / we make.

Greek verb endings usually show the subject clearly, so Greek often leaves out subject pronouns unless they are needed for emphasis or contrast.

So:

• να κάνουμε = for us to do / that we do
• να κάνετε = for you all to do
• να κάνει = for him/her/it to do

Here the photographer wants us to do the photoshoot in the morning.

Because Greek is a pro-drop language. The verb ending already tells you the subject.

• κάνω = I do
• κάνεις = you do
• κάνει = he/she/it does
• κάνουμε = we do

So εμείς is unnecessary unless the speaker wants emphasis, as in θέλει να κάνουμε εμείς τη φωτογράφιση = he wants us, specifically, to do the photoshoot.

Τη φωτογράφιση is the accusative singular form of the noun η φωτογράφιση.

It is in the accusative because it is the direct object of κάνουμε:

• κάνουμε τι; → τη φωτογράφιση

So:

• dictionary form: η φωτογράφιση
• object form: τη φωτογράφιση

In Modern Greek, the final -ν of forms like την is often dropped before many consonants.

Since φωτογράφιση starts with φ, it is very normal to say:

• τη φωτογράφιση

You may also see or hear την φωτογράφιση, especially in more careful or formal speech, but τη φωτογράφιση is completely standard.

Not quite.

• η φωτογραφία = photo, picture, photograph
• η φωτογράφιση = photo shoot, photography session

So this sentence is about the session/event of taking the photos, not about a single photo.

Greek often uses the definite article in time expressions where English may not focus on the article in the same way.

So:

• το πρωί = in the morning
• το βράδυ = at night / in the evening
• το μεσημέρι = at noon / at midday

This is just the normal Greek way to express time here.

It can mean both because and why.

In this sentence, it means because:

• ..., γιατί τότε το φως είναι πιο απαλό.
• ..., because the light is softer then.

When it means why, it is part of a question. Context, intonation, and punctuation make the difference.

Τότε means then or at that time.

Here it points back to το πρωί:

• το πρωί ... γιατί τότε...
• in the morning ... because then / at that time...

It makes the connection more explicit: the light is softer at that time, meaning in the morning.

Yes. Πιο + adjective is a very common way to make a comparative in Greek.

So:

• απαλό = soft / gentle
• πιο απαλό = softer / more gentle

Greek does not need a special ending here. It simply uses πιο = more.

Because the adjective has to agree with το φως.

• το φως is neuter singular
• so the adjective must also be neuter singular
• therefore: απαλό

Compare:

• ο ήχος είναι απαλός = the sound is soft
• η φωνή είναι απαλή = the voice is soft
• το φως είναι απαλό = the light is soft

Because the comparison is only implied, not stated explicitly.

Πιο απαλό means softer or more soft/gentle, but Greek does not have to say what it is softer than.

If you wanted to include the comparison, you could say something like:

• πιο απαλό από το φως το απόγευμα
  = softer than the light in the afternoon

But in your sentence, the idea is simply that morning light is softer, so από is not needed.