1d mark iii w/1.4 tc vs. 7d native

I am trying to plan out a future camera body purchase, so I thought I would come here for some advice. The main use of the body would be for wildlife photography, but I also shoot a lot of pictures of my son and cover events for my job as well as do occasional paid work.

I would be using the camera mostly with the 400mm f/5.6. Due to the extra "reach" of a crop camera, I am thinking that I would want to get a 1.4 tc to make up the extra focal length that I am used to. Is the tc going to degrade my image quality enough that I would be better off sticking with the 400 native on a 7D? From what I've seen, the Mark III produces nicer files than the 7D and most likely has better noise performance due to the larger sensor.

Another factor is MP's. I really like having the smaller files when using my 40D. They offer me some ability to crop with the benefit of having a smaller file to store. I also don't have to worry about my computer being up to the task of working with the files quickly.

People often say that the extra MP's add a great ability to "crop for more reach," but I have also read reports that this introduces a lot of noise. My experience would support this, but I have never shot with a high resolution sensor like what is in the 7D.

If anyone could share their own thoughts/experience I would appreciate it. Choosing to spend the extra money on the 1D is not an easy choice, but I tend to buy for the long term rather than settling for something just to get by. I would also appreciate it if responses came from those with actual experience with the cameras or lenses being discussed, or general canon experience. I don't really care to read a post from someone with a rebel xt and a kit lens that has taken 5 shots and then spent the next five years telling everyone that they have to buy L lenses...

40Driggs wrote in post #12132340
Is the tc going to degrade my image quality enough that I would be better off sticking with the 400 native on a 7D? From what I've seen, the Mark III produces nicer files than the 7D and most likely has better noise performance due to the larger sensor.

A TC is going to degrade your IQ. Whether that loss of IQ is acceptable to you is subjective of course. Keep in mind, a TC is going to drop you to f/8 as well on that lens. You might find that a bigger problem. As for your "nicer files" and "better noise performance" I'm not sure where you get this from or what it even means. I'm sure that you'll be happy with the noise performance of the 7D at 100ISO. Comparing both bodies at 3200 ISO might be a different case, although I'm certainly happy with my 7D's performance in that regard.

Hopefully you don't take this the wrong way, but this really sounds like you've made up your mind on getting a 1D instead of the 7D and are trying to justify the difference between the 10 and 18 MP images. I have tens of thousands of pictures I've kept, in RAW, from my 7D and they maybe take up $100 in storage. Bigger size is a good thing (more pixels per duck!).

Are you actually saying that cropping an image increases noise? Maybe cropping will make any existing noise more obvious, but in that case the bigger the file size the less the effect. Cropping doesn't introduce anything, you are merely removing unwanted pixels from the image.

If I had the choice you have (1d mark III versus 7D) I would pick the 7D in a second. Now a 1D Mark IV versus 7D is a competely different matter.

If I had the choice you have (1d mark III versus 7D) I would pick the 7D in a second. Now a 1D Mark IV versus 7D is a competely different matter. [/QUOTE]

Interesting.
Last autumn I was photographing Otters in west Wales and (after they had gone) stopped to have a chat to another photographer who was doing exactly the same thing. He was using a 100-400 and a 1D3 and had noticed my 1d4 + 600, or rather the expression on my face when carrying it! When he opened his backpack I noticed he had a 7D as well and asked why he had not used it? He stated that he was impressed with the 7D but that in critical situations he preferred the !d3 for (in his opinion) better high ISO, AF and responsiveness. I have had a few plays with 7d's and I like this model, especially the viewfinder, but have not done direct comparisons - he had both and the 7d was his backup!
I was a little surprised but that was his (informed) decision.
The moral is try before you buy. They are both excellent cameras.