The Reality of the "Crop Factor"

[Kayaker72]

Rick...that is exactly the point I have been getting at. There is more side wall with higher pixel densities. Thanks for running the numbers...there is 1.69 more mm side wall per mm for the higher density sensor (7DII) vs the FF (1Dx). I ran the numbers slightly different (5472 rows 15 mm long + 3648 rows 22.4 mm long for the 7DII) and got the exact same ratio.

Now the next part is how thick are the side walls (picture below makes them look about as wide as the pixel itself) and we could calculate the % of sensor area is photosite vs sidewall (electronics, etc). But my suspicion is that the sidewall thickness is similar (to house the electronics). If true, then is 1.69x more photosite area per mm2 for the 1Dx compared to the 7DII. So, larger sensor and a larger % of the area dedicated to photosites.

After that, the question gets to be the microlenses, are they truly gapless, how well do they work, and is there a difference in efficiency depending upon the size of the pixel/microlens? At the end, if the microlenses do their job perfectly, it offsets my original point. But, another suspicion, my guess is that the larger microlenses are better than smaller microlenses.

EDIT...by the way, some interesting photos I found in my searches:

Cross section of a sensor taken by Chipworks. You can see the electrical conduits in the posts between the pixels.

And "gapless" microlenses