Learn Turkish: Kamera çok daha çarpıcı bir görüntü kaydedebilirdi. - The camera could have recorded much more striking footage.

This is the counterfactual past ability being taught in this lesson. It is formed by adding the ability suffix -ebil, followed by the aorist (broad time) suffix -ir, and finally the past tense -di. Together (-ebilirdi), they express that something could have happened but did not. If you wanted to say the camera actually was able to and did record it, you would use the simple past ability: kaydedebildi.

Why does the verb kaydetmek have a d in the middle of kaydedebilirdi?

The verb is a compound of the noun kayıt (record) and the helper verb etmek (to do). First, the ı in kayıt drops out to form kaydet-. Then, because the ability suffix -ebil starts with a vowel, the t in et softens to a d due to consonant mutation. So kaydet plus ebilirdi becomes kaydedebilirdi.

Does the word görüntü mean "footage" or "image"?

It can mean both! Görüntü comes from the verb görmek (to see) and refers to anything that appears or is viewed. Depending on the context, it translates to "image", "appearance", "view", or in the context of cameras, "footage" or "video".