“Judges will not admit a picture that seems to have been tampered with or that distorts any aspect of the scene [or does not render a normal perspective]…That is, the size relationships of objects in the photograph should be equivalent to what they actually are.” 
I found this quote on the “normal lens” Wikipedia article, which is an important topic that I will distill later in this piece, but first I would like to take a trip down memory lane to my days as a nerdy bird obsessed boy who just got a pair of binoculars for Christmas.
I would peer through the magic glasses, and-just as countless nerdy young boys probably had before me-began to wonder how cool it would be if I could zoom in on stuff with unaided vision. Little did I know what fantastical feats my eyes were already pulling off.
To illustrate this fully I need to explain what a normal lens is. This is the definition from the linked wiki article above: “In photography and cinematography, a normal lens is a lens that reproduces a field of view that appears “natural” to a human observer.”
Just to keep from getting too technical, I’ll keep this in the digital full frame sensor format and say that this simply refers to lenses that are somewhere between 40-60mm.
So, imagine you have a 50mm 1.8 (a very popular option made for pretty much every camera system out there) on your camera and a friend standing about 5-8 feet in front of you. If you put the camera up to your dominant eye while keeping your other eye open, the image produced through the lens of the camera would be roughly equivalent to the image produced by your other eye.
Now imagine there’s a full moon rising behind your friend. It looks so impressively gigantic right there on the horizon, so you do what anyone would do with the gear he had handy and take that amazing shot that’s sure to go viral…but, then you look at the back of the camera and the moon is so tiny in relation to how your eye is seeing it.
What gives? I mean your friend is in the proper perspective but the moon is not. Well, as it turns out if you want the moon to appear through the lens the way it does to you other eye the same way your friend appears with a normal lens, you’d really need something like a 200-300mm lens to accomplish it.
Before I explain exactly how weird this is, I want to show you the exact reason why I started to look into this:
This is one of my favorite scenes to photograph. In fact it is the scene that really propelled me, about five years ago at the tender age of 35, to finally get seriously into photography. But, that’s a story for another time.
The problem with this scene is that it is impossible to photograph. After years of attempts to really capture I realized why I was increasingly dissatisfied with the results. You see the smoke stack in the background? When you see this scene with the naked eye it is such a prominent feature in the landscape. But, just like the full moon on the horizon mentioned in the hypothetical photo of your friend it, comparatively, looks so far away. And for a while I thought it was because I was using lenses that were on the wider side. But, this shot above was taken later with a 50mm “normal lens”…
You see the very bewildering and remarkable thing is that your brain is producing an image that seems to be seeing at different focal lengths simultaneously. To jam it into photographic terms, objects that are closer to you, the view is comparable to wider focal lengths and as object get more distant it is more telephoto.
To me as a-now nerdy adult- this is so much cooler than the simple telescopic vision I desired as a kid. Just think about that for a second. How are your eyes and brain working together to do this? I’m not sure myself. But, if I had to guess, the mechanics of the eye are such that it can magnify/demagnify without physically changing-at least in the same way a lens zooms in and out. Then the takes all that information and builds a seamless seemingly complete image of our surroundings. But, I an neither a biologist nor a neurologist.
But, it brings up an interesting question relating to the opening quote, since no camera/lens combination can do what your vision does there really is no way to keep all of the object relationships in a photograph the way they really are…or at least the way they appear to our eye.
 International Center of Photography (1984). Encyclopedia of photography (1st ed). Crown Publishers, New York supra note 88, at p.208