it is based on the way you keep a small device in your hands. when we are talking about items like phones, i keep my fingers around the corners when taking a photo. i shouldnt have to pay attention to it, but with iphone i have to. if you turn your iphone on a way that the cam is in the lower corner (home button on the left) you will block the cam by your right hand. you always have to think about which corner the cam is. and it shouldnt be like this. basicly you should always turn it on the way that the home button is on the right. even then you need to control your left hand fingers other than the thumb and index finger. not a very practical solution especially if you have only couple of seconds time to take the pic..
and this is the first thing i noticed with iphone althought i was already used to it with ipad.
couple examples:
this is the way most of us probably keep a phone in our hands, placing the fingers around the corners:
https://90a2cc4b7deb50ba0492-5793e9....ssl.cf1.rackcdn.com/2013-04-26_041516-ad.PNG
look how the dude needs to lift his fingers not to block the lens. this is the first thing i noticed when i was taking the first pic:
http://mathiaspastwa.com/wp-content/uploads/2015/06/Take-Photos-With-iPhone-Camera.jpg
placing your hands like this (anyone?), you need to keep in your mind that the cam is in the left upper corner (uhm.. in which corner the cam was again?):
http://www.technobezz.com/files/upl...x-IPhone-66-Plus-Camera-Black-Image-Issue.jpg
i think that this is one thing apple didnt pay attention or they didnt bother to place the cam again. dont know, but it doesnt feel right. it is a little annoying feature.