Phoenixkh wrote in post #17482603
I already mentioned this in one of the 100-400ii threads. I was at a semi local bird rookery this past Tuesday. There were 7 Canon shooters there.... 4 of us had the 7D2 and 100-400ii combo. One of the guys had a 1DX and the 200-400 w/1.4X. That lens is a beast.... I'm sure it's excellent but man, is that thing huge. I have to say.. it was nice seeing something so nice and not being envious. I am content with my 7D2/100-400ii combo.
From time to time, I do wonder about the improvements when using a full frame camera. One of the guys where I was on Tuesday was using a 300 f/2.8 on a 5D3. His comment was.... I was going to buy a 7D2 but decided to get a 5D3 and I can't believe the difference. I wasn't sure what to say so I just said: "The 5D3 is an excellent camera." I didn't ask him what he was using with his 300 f/2.8 before he got his 5d3.
I know I'm rambling here..... I guess I feel guilty for not feeling guilty for shooting a crop camera.

Is there something wrong with me?
You're waking up to reality.
If you take the 6D, 1Dx, and 5D3, and put black paint borders on their sensors to make them all 1.6x crops, the 1Dx is the only one that will have less noise than the 7D2, and that is only at high ISOs, with the 7D2 superior at base ISO. The 6D will have about the same noise t high ISOs (and more at base ISO, true even more so for the 5D3), and the 5D3, a little more noise at high ISOs, due mainly to pattern noise. The 7D2 of course will put more pixels on subject than any of them, and the 1Dx has more pattern noise than the 7D2, so there may be no noise benefit to the 1Dx at all in practice, especially when you consider the fact that the higher pixel density on the 7D2 allows more aggressive NR while still keeping more detail than the 1Dx. Operationally, I imagine that the 5D3 and/or 1Dx may have some benefits, like the faster burst rate of the 1Dx.
Note: this is the first time in recent years that Canon has had an APS-c camera that had FF-competitive high-ISO noise per unit of sensor area in an APS-c sensor, which is why the concept of "equivalence" seemed to be false before. Everything has changed now.