I stitched 116 photos together to make a panorama. Here's the result.

This is the Seattle skyline viewed from Gasworks Park.

It's compiled from 116 different photos, captured with a telephoto lens and stitched together using photoshop. My goal is to see how this photo-stitched skyline compares to an image created with a single photo through a wide angle lens. 
Warning: This post is about to get geeky. 
I shot this with a Canon 5DMk3 using a 70-200mm lens and a 2x extender, so the effective focal length was 400mm. I shot at ISO 800, f/25 aperture, and a 1/160 shutter. 

Using the 400mm focal length on a full frame body gives extreme shallow focus, so the f/25 aperture helped keep everything in focus. The 1/160 shutter helped reduce motion blur.
Here's an example of a single image for scale reference:

I intentionally overlapped each frame significantly. This helped reduce distortion at the edge of each frame. Hopefully, the image looks less stitched together as a result.
Some of the clouds and ocean were artificially created through copying, cloning, and scaling images, to make the frame a proper rectangle.
The final image is 44,874x11089 pixels. That's almost 500 Megapixels!
Unfortunately, it's pretty impractical for online display. It has a 4:1 aspect ratio, a 417MB jpeg file size, and 60x more pixels than the top-end 4K monitors. 
Here's a similar shot of the skyline, taken with the same 5DMk3 and a 24mm lens.

Now here are both images cropped, and stitched together. 

The 400mm merged image flattens the space. The buildings, clouds and water seem like they're on the same plane plane. The waterline is close to a straight line. 
The 24mm cropped image has more depth. The waterline is bowed. The center of the image bulges backwards on the Z-axis.
I matched these based on the size and location of the Space Needle. Though the Needle is nearly identical, the rest of the city appears smaller in the 24mm image than in the 400mm image. They  appear further apart horizontally in the 400mm stitched image. Notice how the building on the far left is significantly further to the left on the 400mm image than on the 24mm image.
Frankly, I expected a more pronounced difference between the two images. I imagine that I could manipulate the 24mm image to closely resemble the 400mm version in Lightroom. This would save a considerable amount of time, effort and hard drive space, compared to stitching 116 images together.
It was a fun test, and I hope you find some interest to it. That said, I don't plan on photo stitching hundreds of photos together again any time soon.

-Andrew