Originally posted by LeeRunge It's not like the D750 is way down the list. No matter what you pay you also don't get the Tamron or Sigma 150-600 or the AF in the Nikon with Pentax, also a factor. Sensor size isn't everything in a camera.
On DxO the score would indicate you shouldn't be able to tell the difference between the D750 and the K-1. But that's because DxO is so heavily weighted towards low light performance. But best case scenario a D750 is little better than a K-3.
D750 2900 lw/ph extinction at over 4000 lw/ph
Pentax K-3ii with Pixel shift 2900, 2750 without.
That's less than a 5% difference in resolution, or even with Pixel Shift.
The K-1 is 3450 lw/ph with Pixel shift. 3350 without. The K-1 is about 20 % more resolution than a D750 with Pixel Shift, 15% without.
The D750 is about the same as a K-3 with pixel shift or 9% difference without.
Th kicker though will be if when the K-3 replacement comes out, the accelerator cleans up the K-3ii image to D750 levels. It's quite possible that from 100-1600 ISO the K-3 replacement will be able to surpass or match the D750 where it is strongest. DxO hasn't rated any camera with he accelerator unit,
At 100 ISO the D750 image can't hold a candle to a K-1.
At 100 ISO the D750 is marginally better than the K-3, probably because the K-3ii is further away for the same image.
The D750 is decidedly better than the K-3 or K-1 at 3200 ISO, if you shoot in low light. The K-1 is the best camera in good light. IN good light the K-3 is only marginally worse than the D750. So in essence, the D750 is better at the worst images. IN good light you may as well have a K-3II, plus with a K-3ii a Pentax 150-450 is longer and gives you more subject resolution than a D750 with a Sigma 150-600.
So I definitely don't agree with your choice. A K-3ii which can match the D750 with pixels shift and is darn close without is around $800 now. $1500 for a D750 seems like a waste of money, it needs bigger more expensive glass and even really expensive long glass is better used on 24 MP APS_c. But, if all your shooting is done at high ISO it's pretty good looking camera. I am almost always able to take my images, even small birds where I have to keep the shutter speed up at 800 ISO or less.
At 1600 ISO or higher no Pentax matches the D750 in the red channel for detail. The camera does have it's strong points. At 100 ISO the D750 isn't close to K-1 resolution. But that's why we shoot 100 ISO whenever we can.
LeeRunge doesn't need resolution (or so he says), I don't need really high ISO performance. Each to his/her own.