Canon 5Diii - image quality?

Well, with wide angle, DOF isn't really a concern, and at very low ISOs for a daylight shot, again not going to be anything that can really be noticed IMO.

The issue here is expectation and lens, it seems...

Nothing to do with the distortion, but as someone touched on, the exposure of 1/250 at f/8 (ISO 125) is likely about one-stop too much.

Van Gogh wrote in post #18433924
Where full frames shine are high ISO performance and shallow Depth of Field for portraits.
There is not going to be an astronomical jump for image quality even in that scenarios but the difference is there.

And big prints. Compare at 30x40 inches, and the difference is clear.

RDKirk wrote in post #18434744
And big prints. Compare at 30x40 inches, and the difference is clear.

True. But way too frequently blown all out of proportion. An acquaintance prints 20"x30" from a 7D all the time. They look fantastic. My family doctor's office is festooned with huge prints of his vacations (ironic, I help pay for those vacations). His goto camera is a P&S. Some of them are from his cell phone.

If bigger is better, why stop at full frame 35mm? Get yourself a 6x7, or 8x10 plate camera. My BIL does gallery exhibits of his photography. Shots from his 645D hang along-side shots from his Panasonic P&S. Artistry is not in the tools. It's in the artist.

Correction:
My BIL shoots a Pentax 645 film camera, not a 645D.

Bassat wrote in post #18434755
True. But way too frequently blown all out of proportion. An acquaintance prints 20"x30" from a 7D all the time. They look fantastic. My family doctor's office is festooned with huge prints of his vacations (ironic, I help pay for those vacations). His goto camera is a P&S. Some of them are from his cell phone.

I was concerned that prints from my lowly 8mp APS-C 20D would not be great beyond 11x14. That was until one of my shots of a rehabilitated dolphin release was blown up to 3x5 feet (not by me; I would have tried to talk them out of it) and displayed in the Long Island Aquarium. It looked fine at a distance, which was the intention.

If one's concern is that a blade of grass in a landscape shot be perfectly resolved when looked at from a reading distance, yeah, go to a 135 sensor or even bigger. But you be too close for the larger picture.

Give it some time. Get used to the camera as a whole. When you are comfortable with it in your normal shooting conditions, you will try it in new and more challenging conditions and then one day a year from now, you'll open a file from your 550D and wonder why it's broken. There is a huge difference to me. But when I upgraded (the same camera to the same camera) I felt the way you did. It took me a while to appreciate the differences. You'll be amazed at what you can pull of with that camera, but it takes time to appreciate it.

Another factor of your distortion is that your crop sensor sampled from the centre of EF lenses. That same lens on your crop body would not have shown that much horizon and therefore the distortion would not have been so in-your-face noticeable.

Also, the 24-70 is a nice entry-level L lens, but as discussed, it is not perfect and will need some tweaking in post.

joedlh wrote in post #18432765
Um, the Earth is a sphere. The horizon is mostly perceived as flat, but it's not. A wide angle lens will make the curvature more apparent.

Yes, but we happen to live on the outside of that sphere, not the inside. And, had the horizon line been framed in the bottom (opposite) portion of the image, the horizon would be smiling, not frowning. The curvature of the earth is not the primary reason for the arcing of the horizon line - distortion is.

Bassat wrote in post #18434755
True. But way too frequently blown all out of proportion.

Good one.

A lot depends on what kind of detail is in the image to being with. Some images simply don't have significant detail. Or course, it also depends on the discrimination of the viewer, as well.

There is a reason discriminating landscape fans are hung up on sharpness and sensor/film size: There is essentially no limit to the amount of detail landscape aficionados like to see in a wall enlargement. I once saw a guy at a gallery whip out a loupe to examine a landscape.

For portraits, most people consider it "sharp" when facial hair is resolved if the scale of the image is large enough to expect facial hair to be resolved. At 20 megapixels, a 24x36mm sensor can resolve facial hair in a loosely posed group shot enlarged to 30xx40 inches.

Up until the 5D Classic, I used both 4x5 and 6x7. Here is the test that finally convinced me to retire my Mamiya RZ67

Interesting post. Most certainly, image content and anticipating viewing situation matter in large prints. Incidentally, I gave up MF in 1976 when I got my first 35mm SLR.

Correction: My BIL shoots a Pentax 645 film camera, not the 645D.

Bassat wrote in post #18435668
Interesting post. Most certainly, image content and anticipating viewing situation matter in large prints. Incidentally, I gave up MF in 1976 when I got my first 35mm SLR.

Correction: My BIL shoots a Pentax 645 film camera, not the 645D.

I was deep into my f/64 period in 1976--rolling in medium format, going into large format.

SereneSpeed wrote in post #18434867
Give it some time. Get used to the camera as a whole. When you are comfortable with it in your normal shooting conditions, you will try it in new and more challenging conditions and then one day a year from now, you'll open a file from your 550D and wonder why it's broken. There is a huge difference to me. But when I upgraded (the same camera to the same camera) I felt the way you did. It took me a while to appreciate the differences. You'll be amazed at what you can pull of with that camera, but it takes time to appreciate it.

Another factor of your distortion is that your crop sensor sampled from the centre of EF lenses. That same lens on your crop body would not have shown that much horizon and therefore the distortion would not have been so in-your-face noticeable.

Also, the 24-70 is a nice entry-level L lens, but as discussed, it is not perfect and will need some tweaking in post.

Agree with this. I had the same thoughts. The change from crop to full frame is more subtle than some people think IMHO. Plus some don't realise the downsides of FF such as what you are seeing in the distortion, more vignetting. That's said, I love my 5d now, definitely takes a long time to learn the camera properly though.

The 24-105 is a fab lens, but it does have its faults. Some love it, some bash it, you'll need to work it out for yourself

Enjoy your new camera.