I took a photo from the same location with my iPhone and a 400mm lens on my Canon 7D2 DSLR. This is the iPhone photo above.
This is the 400mm lens photo on a Canon 7D Mark 2 body. There is a huge difference, as you would expect. This Canon 7D2 body has a cropped sensor so the field of view is the same as a 640mm lens on a digital camera with a full size sensor (24x36mm). More about that here.
This Google Earth Pro satellite image shows my location at the top of the yellow line. The cluster of geese in the Canon 7D2 photo is at bottom of the yellow line. They are about 130 yards from my location.
The Red X on this iPhone image shows the tree and bush in the background of my Canon 7D2 image, shown below again.
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