Learn Turkish: Görüntü çok karanlıktı, daha iyi bir aydınlatma kullanabilirlerdi. - The footage was very dark, they could have used better lighting.

This is the counterfactual past ability form. It starts with the verb root kullan (use). Then we add the ability suffix -abil, followed by the aorist (broad tense) suffix -ir, the plural -ler, and finally the past tense copula -di. Combining the ability suffix with the aorist and past tense (-abil-ir-di) expresses an action that was possible in the past but didn't actually happen, translating nicely to "could have used."

Can I say kullanabilirdiler instead of kullanabilirlerdi?

Yes, you can! Both kullanabilirlerdi and kullanabilirdiler are grammatically correct and mean the same thing. Putting the plural -ler before the past tense -di is generally more common and sounds a bit more natural in modern Turkish, but both suffix orders are perfectly fine to use.

Why is the word order daha iyi bir aydınlatma instead of bir daha iyi aydınlatma?

In Turkish, when an adjective modifies a noun that has the indefinite article bir, the article almost always comes directly before the noun, squeezed between the adjective and the noun. So "a better lighting" becomes daha iyi (better) + bir (a) + aydınlatma (lighting). Putting bir at the very beginning would sound unnatural.

I learned that means "image" or "view." Does it also mean "footage" like in the translation?