Hello,
These days digital cameras can capture both photos and videos.
A photos quality(clarity) is related to the number of pixels the lens and camera can capture within the area of the photo. The more pixels the better the quality of the photo. 1 MP(mega pixel) = 1,000,000 P (pixels).
A videos quality is related to the cameras ability to record video frames with the most resolution(detail) (i.e. 720p, 1080p, 4K, 8K). The faster (frames per second) the camera can record at each resolution will produce a smoother video.
Change advanced camera settings
"Change the Main camera resolution
On supported models, the Main and Fusion camera resolution is set to 24 MP by default. You can switch between 12 MP, 24 MP, and 48 MP."
Record videos
"Record HD or 4K video
Depending on your iPhone model, you can record video in high-quality formats, like HD, 4K, HD (PAL), and 4K (PAL).
- Go to Settings
> Camera, then tap Record Video. - Select from the list of video formats and frame rates that your iPhone supports.
- Note: Faster frame rates and higher resolutions result in larger video files.
Videos you record at faster frame rates can be played back at slower speeds in the Photos app. See Trim video length, adjust slow motion, and edit audio.
Note: PAL is a television video format used in many countries and regions in Europe, Africa, Asia, and South America.”
I am not sure what product you are wanting to take photos of but 8K is possibly over what you would actually need or be able to use for advertising. If you do need to record videos in 8K an iPhone would not be the product you need. If you just need to take high resolution photos, any of the recent iPhone models can help you achieve that.
I hope this helps.