1Dx image quality compared to 6D..

You may be correct but the 6D is much better at higher iso , as are the 1DX and 5D3...

That may be somewhat true, but my response was to the AF statement, nothing about ISO.

However now that you bring up ISO, "much better" is not a very good measurement, the 7D2 isn't quite that far off, and also, long exposure noise is better than the 6D and 5D3, so much so that it currently is the king of Canon bodies for astro photography, but the 80D may be better now.

TeamSpeed wrote in post #17953085
However now that you bring up ISO, "much better" is not a very good measurement, the 7D2 isn't quite that far off, and also, long exposure noise is better than the 6D and 5D3, so much so that it currently is the king of Canon bodies for astro photography, but the 80D may be better now.

True words. The thermal noise and banding of the 7D mk II are dramatically better than the 6D and will give you more true detail instead of photon noise if properly exposed.

GregDunn wrote in post #17954141
True words. The thermal noise and banding of the 7D mk II are dramatically better than the 6D and will give you more true detail instead of photon noise if properly exposed.

Don't mean to sound rude but I've already stated that I have no interest in a crop camera .... And yet the thread seems to be turning into a 7DmkII promotion..
It may be a good camera for those who want a crop camera but I am only interested in full frame..

FarmerTed1971 wrote in post #17952356
Why not? The 6D/7D2 combo is pretty sweet.

I find the 7D2 to be better for birds than the 6D, as long as I'm not too close to a big one and need the wider FOV. That's really the only way that a 1Dx, 5D3, or 6D can get a better bird photo than the 7D2; you fill the frame by shooting a bigger bird or getting closer (good luck there!). An APS-C crop from the 6D has a hair less high-ISO noise than the 7D2 on paper, but the fact that the 7D2 gives you a lot more pixels leaves more room for NR and for the noise to dither nicely. The 1Dx crop has less high-ISO noise than the 6D by about 1/3 stop or so, but the character is not as good as the 6D or 7D2. The 5D3 has about the same noise as the 7D2, but the character is the worst of the 4 cameras, with the most visible banding.

The bottom line is that if you are not filling your frame with the FF camera, it gets you nothing in practice; it is *not* a larger "antenna" that pixels up a stronger signal; it only gets more signal by getting a wider composition in sensor area, *when* you do get it. Of course, functionally, the 1Dx is better than the 7D2 in many ways, like less shutter lag and faster burst speed.

TeamSpeed wrote in post #17952802
The 7d2 and other announced bodies match the 6d in low light AF.

Owning both, my general feeling (without any explicit testing) is that the 7D2 center point AF actually works a little bit better in low light, and why wouldn't it? The 7D2 is f/8 center-point, and the 6D, f/5.6. That would mean that all other things being equal, the 7D should be able to make the best of the situation. I doubt that the limits of EV and f-number work as independent thresholds, where you have to satisfy both and AF works, or it doesn't work. They are factors that work together and results are the product of the lack of combined weaknesses. Any of a few things help AF work; a sharp (wide open) lens, smooth bokeh, f-number ability, and subject contrast and illumination.

If the only difference is f-number limits, wouldn't one expect an f/5.6 lens to work better on an f/8 AF point than on an f/5.6 AF point?

Looks like you lost your thread.

John Sheehy wrote in post #17954981
Owning both, my general feeling (without any explicit testing) is that the 7D2 center point AF actually works a little bit better in low light, and why wouldn't it? The 7D2 is f/8 center-point, and the 6D, f/5.6. That would mean that all other things being equal, the 7D should be able to make the best of the situation. I doubt that the limits of EV and f-number work as independent thresholds, where you have to satisfy both and AF works, or it doesn't work. They are factors that work together and results are the product of the lack of combined weaknesses. Any of a few things help AF work; a sharp (wide open) lens, smooth bokeh, f-number ability, and subject contrast and illumination.

If the only difference is f-number limits, wouldn't one expect an f/5.6 lens to work better on an f/8 AF point than on an f/5.6 AF point?

Handy to know if I wanted a crop sensor.... BUT I DON'T....

don1163 wrote in post #17953076
You may be correct but the 6D is much better at higher iso , as are the 1DX and 5D3...

The 6D is only better at high ISO if you use the whole frame. Don't forget, you have to use a 1.4x TC to get about the same number of pixels on target with a given lens with the 6D! That means that you will be using double the ISO, losing all of the alleged benefit of the 6D, while adding extra glass distortion and contrast loss, as small as that might be. You will also have much less AF ability. The 7D2 gives you f/8, while you can only use an f/4 lens with a 1.4x on the 6D, because the 6D is a f/5.6 camera for phase-detect AF. Or, as I said in another post, you can get closer to your subject and get the FF benefit, but that is not always possible.

Don't be fooled by "FF IQ superiority", as it is often a myth, and requires a closer subject distance, bigger lens, shallower DOF for the same FOV, f-number much less than f/2.8, etc (and that doesn't help with the 5Ds, AFAIK).

The amount of noise in your subject does not vary with 7D2 vs 6D, what it varies with is the effective physical aperture of your lens. The bigger your "eye", the less noise you will have. Crop factor only means narrower FOV in that context. Higher pixel density in the 7D2 means more room for NR without losing details.

I would never recommend a FF camera (except maybe the 5Ds) alone over the 7D2 for people shooting elusively small and distant things. In that context, the only value of the larger sensor is that you get more jumproom, but unless that FF is the 5Ds, it means a lot less resolution with little or no noise benefit.

GregDunn wrote in post #17954141
True words. The thermal noise and banding of the 7D mk II are dramatically better than the 6D and will give you more true detail instead of photon noise if properly exposed.

Photon noise is not behind banding and thermal noise. Photon noise is the very fabric of light, on its particle facade.

John Sheehy wrote in post #17954997
The 6D is only better at high ISO if you use the whole frame. Don't forget, you have to use a 1.4x TC to get about the same number of pixels on target with a given lens with the 6D! That means that you will be using double the ISO, losing all of the alleged benefit of the 6D, while adding extra glass distortion and contrast loss, as small as that might be. You will also have much less AF ability. The 7D2 gives you f/8, while you can only use an f/4 lens with a 1.4x on the 6D, because the 6D is a f/5.6 camera for phase-detect AF. Or, as I said in another post, you can get closer to your subject and get the FF benefit, but that is not always possible.

Don't be fooled by "FF IQ superiority", as it is often a myth, and requires a closer subject distance, bigger lens, shallower DOF for the same FOV, f-number much less than f/2.8, etc (and that doesn't help with the 5Ds, AFAIK).

The amount of noise in your subject does not vary with 7D2 vs 6D, what it varies with is the effective physical aperture of your lens. The bigger your "eye", the less noise you will have. Crop factor only means narrower FOV in that context. Higher pixel density in the 7D2 means more room for NR without losing details.

I would never recommend a FF camera (except maybe the 5Ds) alone over the 7D2 for people shooting elusively small and distant things. In that context, the only value of the larger sensor is that you get more jumproom, but unless that FF is the 5Ds, it means a lot less resolution with little or no noise benefit.

I am totally at a loss as how 'I am not interested in a crop sensor' is being interpreted by people as 'please convince me that a crop sensor is best for me'...
Thanks for your input but no thanks a crop is Not what I want.

don1163 wrote in post #17954996
Handy to know if I wanted a crop sensor.... BUT I DON'T....

Well, some of us might be concerned that what you want is not what you need. The 6D is not going to get you better pictures of small birds, period. The 6D can only give you a better shot of a bird or a given region around it in a composition with the same lens, to get the FF IQ that you've heard so much about, if you get 1.6x closer. There's no magic with a bigger sensor. You need to get closer (and therefore have lower DOF) with the same lens! This is a fact that many people seem to miss. I've been shooting small birds for over a decade, and rarely has an APS-C ever made me wish I had my FF with me at the time; that generally only happens with larger birds that allow close approach. My 6D stays at home and goes out with me when I am shooting with super-wide angles and fish-eyes, f/1.4, etc. Things where FF have an edge.

There was a time when I had a 6D and a 7D "mark I". Then, I used the 6D in low light because you actually got reduced noise in return for losing resolution, or having to use a TC.

I traded in my 5Diii for a 1DX. I also own the 7 Dii. If I could swing it I would have two 1DXs. The 1Dx is better for even birds. I read others saying that and did not believe it. It's true. Better images cropped in and more keepers than 7Dii. Same with sports. 6d, 7dii and 5diii are all great, nothing wrong with any of them, that is why it is a tough descision and long thread.

Get the 1DX other wise you will be second guessing because you don't have the top camera. Best being relative. The new 5Ds for landscape seems killer too

I would get either the 1Dx or the 5Dsr then, if a crop sensor is totally out of the question.

5Dsr is beter DR wise, but has adequate af for stationary wildlife and better af than the 6D, and miles of cropping available.

1Dx is the way to go for birds on the move.

There is a trade off for 'pixels on the target' though, depending on how deep the pockets are for longer lenses.

That is why we keep bringing up the 7DII, people pairing that with the 100-400mm v2 are very happy with that combo for birds and wildlife. You mention the worry of losing croping with the 1dx, and the 7DII is very good at making up for that. There are merits to both, and how much you want to spend usually determines the equipment direction. Usually AF, and pixels on the target are Number 1 and number 2 for birding... then high iso performance, then DR is down the list. JMHO, YMMV.

John Sheehy wrote in post #17955019
Well, some of us might be concerned that what you want is not what you need. The 6D is not going to get you better pictures of small birds, period. The 6D can only give you a better shot of a bird or a given region around it in a composition with the same lens, to get the FF IQ that you've heard so much about, if you get 1.6x closer. There's no magic with a bigger sensor. You need to get closer (and therefore have lower DOF) with the same lens! This is a fact that many people seem to miss. I've been shooting small birds for over a decade, and rarely has an APS-C ever made me wish I had my FF with me at the time; that generally only happens with larger birds that allow close approach. My 6D stays at home and goes out with me when I am shooting with super-wide angles and fish-eyes, f/1.4, etc. Things where FF have an edge.

There was a time when I had a 6D and a 7D "mark I". Then, I used the 6D in low light because you actually got reduced noise in return for losing resolution, or having to use a TC.

If you had read my original post you would see that I don't want to buy a 6D....As I already have one..
What I want is to upgrade to the 1DX...