46 megapixel canon Locked

46MP FF wouldn't bee a huge increase in resolution, either.  Just to double the resolution of the 5D3 would require 88MP.

It's nice that you can do that, but you have to deal with aberrations in each image, or leave them in and leave artifacts.  It's much easier to have a single projection by a lens.  Ideally, you would take a lens for a large format and move the sensor relative to the lens; then when you stitch, you have a single optical projection to correct.

The way Canon sensors work, once you have eliminated banding noise, the only ay to have more DR is to have more pixels in the sensor, as Canon's base-ISO noise floor seems to be determined not by the pixels themselves, but by the CMOS circuitry reading the sensor.  Over the past 10 years, the base-ISO DR of Canon DSLR pixels has not varied more than about 1/2 stop, and your XTi is actually one of the better ones; better than the 5D by a stop, and very low in banding noise.

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John
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