I have had this question asked by a couple of people and on further research, I have seen a few people ask this question on the internet so I decided to test it for myself.
Is the narrow mode on the Go Pro HD Hero 3 simply a crop of the wide view? If so, this would obviously render the footage from the narrow view much poorer quality.
To check this once and for all, I put clips from both the narrow and wide view into Sony Vegas Pro. I then zoomed in on the wide view shot to closely match the footage taken from the narrow view.
The results below show clearly (to me anyway), that whatever Go Pro do to get the narrow view, it doesn’t affect the quality of the footage. I am assuming that because the Go Pro HD Hero 3 now has a 4k sensor, the image is actually cropped to provide a narrower view (by using a smaller portion of the sensor) but still retains the 1080 resolution.
100% Still Image from 1080p “Narrow” Resolution (Click to see full size):
Cropped Still Image from 1080p Wide Resolution to Match Image Above (Click to see full size)
To my eyes, the difference is clear. The image taken from the narrow view footage is noticeably clearer and sharper than the cropped image taken from the wide field of view image.